The growth of a pre-Inca civilization known as the Wari may have been aided by psychedelic-laced beer, researchers propose in a new study.

The Wari flourished from roughly A.D. 600 to 1000 and are known for their mummified burials, human sacrifices, and elaborate objects created out of gold, silver and bronze. They also built cities such as Huari and Pikillaqta, which contained temples and dwellings for elite inhabitants, and controlled much of Peru as well as parts of Argentina and Chile.

In the new study, published Monday (Oct. 6) in the journal La Revista de Arqueología Americana (The Journal of American Archaeology), the researchers suggest that Wari rulers used psychedelics mixed in beer to help grow their empire. They explain that the "afterglow" — the long-term effect of drinking the mix — would have lasted weeks and that communal feasts where it was drunk would have brought people together. While the body may excrete psychedelics quickly, the aftereffects can last for days or weeks.

The study authors noted that the remains of seeds from a plant named Anadenanthera colubrina (also known as vilca) have been found at Wari sites, including near the remains of beer made from a plant called Schinus molle. Mixing the vilca, which is known to produce a psychedelic effect, with the beer would have "lessened but extended the high," Justin Jennings, a curator of South American Archaeology at the Royal Ontario Museum and co-author of the paper, told Live Science in an email.

In the paper, the authors noted that scientific studies of similarly acting psychedelics found that people who took them tended to display "greater openness and empathy."

These traits "would have been highly desirable for a Wari political system that depended on friendly, routine face-to-face interactions between people who had once been strangers or even enemies," the researchers wrote in their paper.

People would have drunk the psychedelic beer together at communal feasts held within enclosed areas at the residences of Wari officials. This shared experience would have enhanced the event, the researchers said.

"When guests came to the Wari compounds, they gathered in patios that could only comfortably fit a couple dozen people," the team wrote. "Except for a patch of sky, they were cut off from the rest of the world in a high-walled interior space — this was the place where they would spend hours together drinking, eating, talking, and praying," the researchers wrote in their paper.

"The hours that participants spent together must have been an unforgettable collective experience that forged strong bonds between participants," they added.

Building an empire

The regular, widespread use of the psychedelic beer and its afterglow played a key role in the Wari Empire's consolidation of political power, said Jacob Keer, an independent scholar and co-author of the paper.

The "long-term psychological effects of drinking vilca beer a few times a year could constitute a new cognitive normal, instilling increased openness and empathy in feast participants," the researchers wrote in their paper. "Within the context of an expanding empire where violence and animosity was commonplace, the lingering effects [of consuming it] may have been integral to Wari legitimization and consolidation."

Scholars who were not involved with the research had mixed reactions to the conclusions in the paper, however. Patrick Ryan Williams, director of the School of Human Evolution and Social Change at Arizona State University, said the team put forward an "interesting hypothesis" but cautioned that we can't be certain that vilca was actually mixed into beer.

"I am not convinced, however, that the discovery of vilca seeds in an area where molle beer was consumed constitutes evidence of vilca being included as an ingredient in beer," Williams said, as it would be like finding cocaine on the floor of a nightclub and assuming the drug was put into drinks.

"When a chemical trace for vilca is found in the ceramic pores of drinking cups, I will be more open to the premise presented here," Williams said.

Mary Glowacki, an archaeologist and president of the Pre-Columbian Archaeological Research Group, called the paper "thought-provoking" but noted that "most early Andean societies used intoxicating substances — including vilca — for political negotiation." She questioned whether the Wari's use of psychedelics was greatly different from that of other groups in the region.

Beer is one of the most popular beverages in the world, with nearly every country having its own local lager. In the U.S. alone, the overall beer market in 2023 totaled $116.9 billion, and breweries shipped out 192 million barrels of beer.

But the ice-cold, bubbly beverage we know today didn't always exist. So when was beer invented?

The answer traces back thousands of years. But there's still some mystery surrounding the exact origins of beer, and the beer of ancient times probably didn't taste anything like what you're used to today.

"We don't actually know exactly how [beer] was discovered," Tate Paulette, an associate professor of history at North Carolina State University, told Live Science. "Partly because of the kind of evidence we have, it's unlikely that we're going to get that kind of answer."

Because humans discovered fermentation so long ago, it's difficult to find evidence of exactly where beer-making began, Paulette explained. Much of the evidence comes from organic-residue analysis, he said.

Using this technique, archaeologists can identify the chemical signatures of grain fermentation on ancient ceramic or stone vessels. Researchers have found strong evidence of beer brewing as far back as the Neolithic period (10,000 to 4,000 years ago), when agriculture took root, in sites all around the world.

The oldest beer

Kirk French, an assistant professor of anthropology at Penn State, pointed to 9,000-year-old sites in China as the best evidence for ancient beer brewing. At the Qiaotou archaeological site in southeastern China, archaeologists found residues of plants, yeast and mold on ancient pots near human skeletons, suggesting that they once contained a beer-like fermented beverage. Analyses indicate that the beverage those pots contained also included rice, tubers and fungi.

Another site in China from the same time period, Jiahu, also contains bronze vessels with chemical signatures of grain fermentation, as well as residues of rice, honey and fruit.

French said the Jiahu site contains the most foolproof evidence of ancient beer because the chemical residues were found in drinking vessels. There are even older potential instances of beer brewing, but the evidence isn't as strong. That's because analyses of the older sites rely on residues found on cookware, which also could have been used to make bread or porridge; both foods involve a small amount of fermentation and can leave the same chemical signatures as beer brewing.

Related: Why is alcohol used to preserve things?

One of these older sites is an 11,000-year-old cultic feasting location in Turkey. At the site, named Göbekli Tepe, researchers found large stone kilns with residues of ground grain. Although these kilns also could have been used to grind grain for bread, one of the researchers argues that the finish on the stone suggests the grain was ground coarsely, in a manner more appropriate for fermenting beer or making porridge than for baking bread.

Some archaeologists have proposed that beer dates back even earlier, to a 13,000-year-old cave near Haifa, Israel. There, researchers found starch granules in pits taken out of the bedrock that could indicate fermentation. But again, it's possible these stone pits were used for making food rather than drinks.

"It's totally possible (and maybe even likely) that they were making beer," French told Live Science in an email. But ultimately, he said the evidence is too ambiguous to make a conclusion.

Paulette said we likely will never know the exact date that humans brewed their first batch of beer, though emerging evidence continues to push the potential date back further and further. Both experts agreed it's unlikely that beer was "invented" in one place and spread from there; rather, fermentation was probably independently discovered by different groups of people throughout the world.

What did ancient beer taste like?

Though it's still a mystery exactly when and where the first beer was made, one thing is clear: Ancient beer would have tasted quite different from a modern lager.

For one, it would have been sour — a flavor resulting from both yeast and lactic acid bacteria fermenting the grain, Paulette said. It also may have been thick and unfiltered. That's because the process of ancient beer brewing began with a mixture of ground grain and water, and the remaining sediment wasn't always filtered out after fermentation. Paulette said there is some written evidence of "strained" beer in Mesopotamia. But more often than not, imagery and artifacts from the period show that people drank beer through straws with filter tips, suggesting that the beer itself was unfiltered.

In ancient times, beer was also likely drunk shortly after it fermented; otherwise, it could quickly go bad and develop harmful mold or bacteria. Because of this, ancient beer was likely relatively flat and not particularly high in alcohol, unlike our bubbly, boozy IPAs. And without refrigeration technologies, beer was definitely not ice-cold.

French said the beers we know and love today are only about 500 years old.

"They really start in the 1500s, with the Czech beers and German beers," he explained. This is when lagering — the process of cold-fermenting beers that creates a clear, crisp and bubbly beverage — was developed. As Germans migrated around the world in the coming centuries, they brought this brewing technique with them.

"That's why, if you've traveled a lot, it doesn't matter where you go in the world — you can find your basic lager," French said.

From its humble medieval origins as a medicinal agent, vodka has conquered the world. In 2020, the worldwide sales of vodka earned around $45 billion, and U.S. consumers alone guzzled 189.7 million gallons (862.4 million liters) of the potent alcoholic beverage, according to Beverage Dynamics, a national magazine focused on retail alcohol sales. 

But what is vodka made from?

To produce vodka, you must first ferment any foodstuff that contains sugar or starch, then distill the product to increase its alcohol content. (Fermentation means feeding sugar to yeast, so that the yeast can produce alcohol.) Vodka can made from fermented grains such as sorghum, corn, rice, rye or wheat, tor from potatoes, sugar beet molasses or even fruit, according to "Vodka: A Global History," (Reaktion Books, 2012).

The fermentation step creates a product with only about 16% alcohol by volume (ABV) — too low for spirits. Upping that number requires distillation, or heating in a  container known as a still. Alcohol's boiling temperature is lower than that of water, which means the alcohol evaporates and can be collected separately from the water. Most vodka is 30% to 40% ABV. "Rectified spirits," like the American brand Everclear, reach 95% ABV.

Related: Why is fermentation used to preserve things?

The first records of a distilled vodka-like spirit come from Islamic alchemist and chemist Jabir ibn Hayyan, who invented a distilling device to capture the vapor from heated wine for scientific purposes, according to "Vodka: How a Colorless, Odorless, Flavorless Spirit Conquered America," (Lyons Press, 2014). Vodka reached Russia by the 1430s century, when a monk named Isidore adapted the Italian drink aqua vitae, according to the book. This first vodka likely smelled bad, tasted even worse, and was used mainly for medicinal purposes.

Over the course of a few centuries, distillers got better at their practice, the flavor improved, and "voda" eventually became the preferred beverage of the Russian empire, according to the book. 

Vodka's popularity spread with Russian Soldiers, gaining a foothold across Europe during the Napoleonic Wars. In the 1860s, former serf Pyotr Smirnov perfected the distillation process and began selling something that resembled the odorless, clear beverage familiar today.  Following the civil war that established the Soviet Union, Smirnov's son Vladimir moved the distillery to Paris and used a French spelling of his name: Smirnoff, according to the book.

Originally published on Live Science.

The world is full of beautiful equations, numbers and calculations. From counting beads as toddlers to managing finances as adults, we use math every day. But scientists often go beyond these quotidian forms of counting, to measure, weigh and tally far stranger things in the universe. From the number of bubbles in a typical glass of beer to the weight of all the coronavirus particles circulating in the world, here are 10 weird things scientists calculated in 2021.

Related: Photos: Large numbers that define the universe

Beer bubbles

Pouring ice-cold beer into a glass forms lots of tiny bubbles — and thanks to some thirsty scientists, now we know how many. 

These scientists calculated that a half-pint glass of beer produces up to 2 million bubbles, about twice as many bubbles as Champagne makes. But the researchers found that the number of bubbles in a half-pint glass ranged from 200,000 to 2 million, according to their study, published in March in the journal ACS Omega. It turns out that the number of bubbles depends on three factors: the concentration of dissolved carbon dioxide (CO2) in the glass, the volume of bubbles and the point at which the CO2 depletes such that no more bubbles form. Also, tiny flaws in the glass would help bubbles emerge from the liquid.

Read more: How many bubbles are in a glass of beer?

Weight of SARS-CoV-2

If you were to gather all the particles of SARS-CoV-2, the virus that causes COVID-19, circulating around the globe into one place, the weight of the tiny, invisible particles would be somewhere between that of an apple and a young toddler, according to a study published in June in the journal Proceedings of the National Academy of Sciences. That calculation is based on the estimation that each infected individual carries about 10 billion to 100 billion SARS-CoV-2 particles at the peak of their infection. If there are between 1 million and 10 million infections at any given time, which has been the case during the course of the pandemic, the particles together would weigh somewhere between 0.22 and 22 pounds (0.1 and 10 kilograms).

"Here we are talking about a super-tiny mass of viruses, and they are completely wreaking havoc on the world," the researchers told Live Science. 

Read more: How much does all the SARS-CoV-2 in the world weigh? 

Elephants from space

Using satellites and artificial intelligence, researchers counted African elephants from space for the first time, according to a study published online in Dec. 2020 in the journal Remote Sensing in Ecology and Conservation. The team combined high-resolution images of Addo Elephant National Park in South Africa captured by satellites that orbit 372 miles (600 kilometers) above Earth's surface. This novel technique can survey thousands of miles in minutes, which is much faster than the typical way conservationists count elephants in low-flying planes, a process that can take hours. The researchers say this method could be vital for ensuring the survival of the African elephant (Loxodonta africana), a species the International Union for Conservation of Nature classifies as endangered. 

Read more: Elephants counted from space using satellites and AI

Acceleration of a finger snap

Using high-speed cameras and force sensors, researchers figured out the fastest acceleration of the human body: a snap of the fingers. Finger snaps generate maximal rotational velocities of 7,800 degrees per second and a maximal rotational acceleration of 1.6 million degrees per second squared, according to a study published in November in the Journal of the Royal Society Interface. The acceleration of a finger snap is three times the acceleration produced by a professional baseball player's arm. 

"When I first saw the data, I jumped out of my chair," study senior author Saad Bhamla, an assistant professor of chemical and biomolecular engineering at the Georgia Institute of Technology, said in a statement. "The finger snap occurs in only seven milliseconds — more than 20 times faster than the blink of an eye, which takes more than 150 milliseconds." 

Read more: Scientists find the fastest acceleration in the human body

Most precise pi ever

Pi is one of the most famous irrational numbers, which means it can't be expressed as a common fraction and has an infinite number of digits after the decimal point. Researchers in Switzerland have now calculated the most precise value of pi ever, up to 62.8 trillion decimal places. Of course, the calculations, which took 108 days, weren't done by hand but rather with a supercomputer. But don't get too comfortable with this achievement. Because pi is irrational, this record can be broken over and over … forever. 

Read more: Pi calculated to a record-breaking 62.8 trillion digits

Popularity of your friends

According to the "friendship paradox," an idea that was first formulated in 1991, your friends are typically more popular than you are. But a group of mathematicians came up with a new theory that they say better describes real-world friendships, according to a study published in May in the Journal of Complex Networks. "Averages are often highly misleading or at least can fail to describe people's experiences," lead author George Cantwell, a postdoctoral fellow at the Santa Fe Institute in New Mexico, previously told Live Science. "Some people are less popular than their friends; others are more so." 

Their new equations show that the friendship paradox tends to be stronger in social networks made up of people with different levels of popularity, such as a high school. If a person has two friends in the same social network as a person with 100 friends, in general, the friendship paradox will be stronger than in a network where the most social person has 10 friends and the least social person has three. 

Read more: The 'friendship paradox' doesn't always explain real friendships, mathematicians say

Black holes

How many black holes exist in the universe? These mysterious objects are so dense that not even light escapes themt. Astronomers can't detect all the black holes out there, so they turned to theoretical calculations. In a study published in October the preprint database arXiv, a group of researchers calculated that there might be millions of small black holes in our cosmic neighborhood, or the most immediate environment around the sun, according to NASA. The largest black holes, supermassive black holes, are much rarer than the smaller ones; each galaxy usually has only one. All in all, they calculated that black holes hold about 1% of all ordinary matter (not dark matter) in the universe. 

Read more: How many black holes are there in the universe?

Walking around the moon

How long would it take to walk around the moon? The answer isn't black-and-white; rather, it depends on a number of factors, including how fast you walk and how much time you spend walking each day. It also depends on whether you take detours to avoid rough topography. At a hypothetical walking speed of up to 3.1 mph (5 km/h), which researchers previously calculated in a 2014 study, it would take about 91 days to walk the 6,786 miles (10,921 kilometers) around the moon, Live Science reported this year. But because it's not possible to walk nonstop for 91 days, the journey would likely take much longer. It's more likely that a person would walk a few hours a day. If a person walked at this speed for 4 hours a day, it would take about 547 Earth days, or about 1.5 years, to walk around the moon.

Read more: How long would it take to walk around the moon?

Satellites orbiting Earth

In another article, Live Science explored the question of how many satellites currently orbit the planet. Since Russia launched Sputnik, the world's first human-made satellite, in 1957, thousands of satellites have been lofted. About 10 to 60 were launched annually until the 2010s. Since then, the numbers have increased tremendously: 1,300 new satellites were sent to low Earth orbit in 2020 and more than 1,400 in 2021. As of September 2021, there were around 7,500 active satellites in low Earth orbit, Live Science reported.

Read more: How many satellites orbit Earth?

"Absolute limit" on the human life span

The "absolute limit" on the human life span may be 120 to 150 years, according to a study published in May in the journal Nature Communications. A group of researchers calculated that limit using a mathematical model, which predicted that after 120 to 150 years, the body would lose its resilience, or the ability to recover from illness and injury. But if future therapies targeted and extended the body's resilience, humans might be able to live longer, the researchers said. The data for the study came from large data sets that contained medical data for more than 500,000 people across the U.S., the U.K. and Russia. The data included blood tests in which the researchers specifically looked for the ratio of two types of disease-fighting white blood cells.

Read more: Human life span may have an 'absolute limit' of 150 years

Originally published on Live Science.

When you pour a glass of beer, a frothy cascade of fizz rises to the top; as more and more tiny bubbles coalesce, they form a nose-tickling layer of foam. 

At first, that frothy stream of carbonation seems endless. But just how many bubbles can emerge from a glass of beer before it goes flat?

Gérard Liger-Belair, a professor of chemical physics at the University of Reims Champagne-Ardenne in France, had previously explored this effervescent subject in Champagne, calculating that one flute produces about 1 million bubbles. Recently, Liger-Belair peered into the depths of beer glasses and found that they produce twice as many bubbles as Champagne — with up to 2 million bubbles popping in a half-pint glass, according to a new study. 

Related: When was beer invented?

Archaeological evidence shows that people have been brewing and drinking beer for at least 5,000 years and possibly for as long as 13,000 years, Liger-Belair and co-author Clara Cilindre, an associate professor and researcher in the Molecular and Atmospheric Spectroscopy Group (GSMA) at the University of Reims, reported in the study. The beverage "is by far the most popular alcoholic drink worldwide," with global production reaching nearly 53 billion gallons (200 billion liters) per year, and bubbles and foam are an important part of the beer experience, Liger-Belair told Live Science in an email. This is especially true of lager, the most popular type of beer, Liger-Belair said.

"It seems pertinent to us to bring some more knowledge about bubble formation, bubble size and finally about the issue of the total number of bubbles likely to form in a glass of beer along the entire natural degassing process," he said.

Beer is typically made of four ingredients — malted cereal grains, hops, yeast and water — which are then fermented. This process breaks down carbohydrates to produce alcohol, sugars and carbon dioxide (CO2). When beer is bottled or canned, additional CO2 is added, creating pressure in the container. Once the seal on a can or bottle is broken, the liquid becomes supersaturated with CO2, which is then released as tiny bubbles.

For the study, the researchers looked at beer that was 5% alcohol by volume, pouring about 8 ounces (250 milliliters) of beer at a temperature of 42 degrees Fahrenheit (6 degrees Celsius) into 17-ounce (500 ml) glasses. The scientists determined that the overall number of beer bubbles would be mostly affected by three factors: concentration of dissolved CO2 in the glass, volume of the bubbles, and the point at which beer becomes so CO2-depleted that no more bubbles can form.

Tiny flaws in beer glasses also help CO2 bubbles emerge from the liquid, the study authors found. Dissolved CO2 would collect around pits and crevices larger than 1.4 micrometers wide, forming streams of bubbles. High-speed photography then showed the bubbles getting bigger as they rose, capturing even more CO2 from the beer. In total, a glass of beer of this volume would generate between 200,000 and 2 million bubbles, according to the study.

However, this research wasn't just about counting bubbles, the scientists said. When bubbles in a beverage pop on a drinker's tongue, they enhance subtle flavors; by studying effervescence in liquid, scientists can learn how beverages behave under different conditions and how that can affect their taste, Liger-Belair said in the email. 

While the quantity of dissolved CO2 in beer is "a key parameter" for understanding this, the geometry of the glasses that hold the drink also plays an important part, "so that we can easily imagine modifying some beer and glass parameters for a better overall sensory experience," he said. 

"We believe that the beer industry could benefit from more knowledge about bubble science," Liger-Belair added.

The findings were published online March 31 in the journal ACS Omega.

Originally published on Live Science.

In this episode of Life's Little Mysteries, we'll take a closer look at an alcoholic beverage that has quenched thirsts for thousands of years and is one of the oldest chemistry experiments in the world: beer.

How is beer made, and when did people start making it? How many different types of beer are there, and what gives them their distinct flavors? Listen to Life's Little Mysteries Episode 48: Mysterious Beer, to find out! 

You'll also hear about the importance of beer in ancient civilizations, and why — despite the staggering variety of beers available today — some people just can't stand the taste of it. 

Co-hosts: Jeanna Bryner (Live Science editor-in-chief) and Mindy Weisberger (Live Science senior writer)

Guest host: Brandon Specktor (Live Science senior writer)

Guest scientist: Ronen Hazan, microbiologist at the Hebrew University of Jerusalem

Listen to Life's Little Mysteries, Episode 48: Mysterious Beer below or on Audioboom, or subscribe on Apple Podcasts and Spotify, so you don’t miss out on new episodes.

Follow us on Facebook and Twitter for even more Life's Little Mysteries, and catch up on the latest Life's Little Mysteries articles. You can also join the conversation in our forums, where you can pose Life's Little Mysteries questions of your own, or even suggest topics for upcoming podcast episodes. 

Originally published on Live Science.

Drinking alcohol is known to raise women's risk of developing breast cancer, but many women aren't aware of this link, a new study from the United Kingdom suggests.

The study researchers analyzed information from 205 women who were undergoing breast cancer screening or seeking treatment for breast cancer symptoms at a U.K. hospital. The women were surveyed about their knowledge of risk factors for breast cancer.

About half the women surveyed knew that smoking was a risk factor for breast cancer, and 30% recognized obesity as a risk factor. But only about 20% knew that consuming alcohol was a risk factor, the study found.

Even among health care staff, knowledge of the connection between alcohol and breast cancer was still lacking — of 33 health care staff surveyed, 49% identified alcohol as a risk factor for breast cancer. [7 Odd Things That Raise Your Risk of Cancer (and 1 That Doesn't)]

The new study was conducted at a single health center in the U.K., and so the findings don't necessarily apply to the general population. But the findings do agree with previous research conducted in the United States: A 2017 survey by the American Society of Clinical Oncology found that 70% of Americans didn't know that drinking alcohol is a risk factor for cancer.

It's estimated that alcohol consumption is responsible for around 5% to 11% of all breast cancer cases, with higher risks seen among heavy drinkers. A recent study also estimated that drinking a bottle of wine a week is the equivalent of smoking 10 cigarettes per week for women, in terms of their overall cancer risk.

The new study also suggests that it may be difficult for people to estimate exactly how much alcohol they consume. The study showed that more than half of participants couldn't correctly estimate the alcohol content in any of four commonly consumed alcoholic drinks — a glass of wine, a pint of beer, a liter of cider and a bottle of liquor.

"This suggests that many women may be unaware that their level of alcohol consumption may be increasing their risk of breast cancer," the authors wrote in the June 18 issue of the journal BMJ Open.

It's possible that breast cancer screenings and visits for breast cancer symptoms might serve as "teachable moments" to inform women about ways to decrease their breast cancer risk, such as by reducing alcohol consumption, the authors said.

Indeed, when women in the study were asked how they would feel about having a 5-minute session in which they were provided with cancer prevention information at their breast cancer screenings or appointments for breast symptoms, about 30% percent said this would make them more likely to attend those appointments, and 70% said it would make no difference.

This suggests that "women would not be put off attending breast [cancer] screening or clinic appointments if they were aware they would receive some cancer prevention education," and may in fact be more likely to attend, the authors said.

However, more research would be needed about how to best deliver such information. Both patients and health care providers expressed concern that such sessions might come across as placing stigma on women who drink or blaming women for drinking.

• 5 Myths About Women's Bodies
• 10 Do's and Don'ts to Reduce Your Risk of Cancer
• 7 Ways Alcohol Affects Your Health

Originally published on Live Science.

A glass of clear moonshine may look identical to water, but this illicit alcoholic beverage is infamous for its potency — and for the peril associated with drinking it.

What is moonshine? Broadly, moonshine is any type of distilled liquor that's manufactured without government oversight, though some argue that moonshine can be labeled as such only when it is made with certain ingredients or comes from specific geographic regions, experts told Live Science.

People all over the world make and drink moonshine, particularly in places where alcohol is illegal or where legal alcohol is prohibitively expensive or hard to get. But producing spirits can be a tricky chemical process; manufacturers' mistakes, ignorance or shortcuts can yield a highly toxic product. 

So, how does that happen, and how can you tell if a glass of moonshine is safe? [7 Ways Alcohol Affects Your Health]

Alcohol in moonshine and other intoxicating drinks comes from fruits or grains that are fermented — that is, they are exposed to yeasts or bacteria that convert sugar molecules to carbon dioxide and alcohol.

Ingredients for moonshine vary widely depending on what's available. In the early 20th century, American moonshiners typically made their brews from corn mash; in fact, legal versions of traditional American moonshine are commercially produced today by craft distilleries in the United States.

But moonshine is also made from grapes, plums or apricots (Armenia), barley (Egypt), palm tree sap (Myanmar), bananas (Uganda) and cashew fruit (India), said Kevin Kosar, author of "Moonshine: A Global History" (Reaktion Books, 2017).

"It's just basic chemistry. If you can tease sugar out of something, you're on your way to making a drink," Kosar told Live Science.

Potent potables

Fermentation produces two forms of alcohol: ethanol and methanol, which is also known as wood alcohol. Methanol is released from pectin, and is therefore more abundant in fermented fruit, according to research published by the American Chemical Society. Though ethanol is generally considered safe for drinking, both ethanol and methanol suppress the central nervous system and inhibit brain function. Consuming too much alcohol — even the "safe" kind — can cause alcohol poisoning, affecting heart rate and breathing and even leading to coma and death, according to the Mayo Clinic.

Methanol is far more dangerous than ethanol, said Anne Andrews, a professor of psychiatry, chemistry and biochemistry at the University of California, Los Angeles. In the human body, methanol is converted to formaldehyde — the same substance in embalming fluid — and then to formic acid, which is highly toxic to cells, Andrews told Live Science.

"It interferes with their mitochondria, and actually causes cells to suffocate," Andrews said.

After fermentation, moonshine is distilled to concentrate the ethanol and other volatile flavor ingredients. However, ethanol boils at 173.1 degrees Fahrenheit (78.37 degrees Celsius), while methanol boils at 148.5 degrees F (64.7 degrees C). Because methanol has a lower boiling point and it evaporates earlier, it can become concentrated in the distillate — the vapor that is condensed and collected during distillation, Andrews said.  

Regulated alcohol production — including commercial moonshine — is carefully monitored. Products are rigorously tested to ensure that methanol is separated from the beverage and that the amount of alcohol by volume is clearly identified on packaging and labels. But for unregulated moonshine makers, there are no universal guidelines or enforced safety checks. Moonshine can therefore be more potent than legal beverages, and a batch of moonshine can quickly turn toxic, Andrews said.

If fermentation vats are unsterilized, that can promote the growth of bacteria that pump out methanol, resulting in a higher methanol concentration than expected, Andrews explained. And if moonshiners aren't cultivating microbial communities for fermenting the moonshine — "inoculating" it with species that produce mostly ethanol — unexpected shifts in environmental microbes can also generate a methanol spike.

"That moonshine could have been safe for years," Andrews said. "But then something changes in the environment, affecting local microbes that are doing the fermentation. Now there's a higher concentration of methanol, and the person making it would never know."

Poison for profit

In some cases, greed is the cause of moonshine's toxicity. Unscrupulous manufacturers that want to increase the volume of their moonshine either don't remove methanol or add a cheap, toxic alcohol like isopropyl, which is found in rubbing alcohol, said Kosar. Though this tactic may boost profits, it significantly raises the risk that the drink will be poisonous.

"With alarming regularity, there are stories — often coming from parts of Asia — where people go out and buy illicit alcohol, they have a party, and then hours into the party, people just start dropping and having convulsions," Kosar said.

Drinking alcohol with high levels of methanol can also lead to blindness: Methanol caused 130 deaths and 22 cases of blindness in just six months during Prohibition, according to a 1922 article in The New York Times that cited a report by the U.S. National Committee for the Prevention of Blindness.

Even when moonshine doesn't contain toxic levels of methanol, it's difficult for a casual drinker to tell how strong a batch may be without testing it — an uncertainty that could lead to accidental alcohol poisoning. The best way for drinkers to stay safe is to give illicit alcohol a wide berth, Kosar said.

"Unless you're a close friend of the person producing the moonshine and have absolute trust in their competence to produce it, don't drink it," he warned.

Editor's Note: This story was updated to correct the boiling points of ethanol and methanol; to note the legal production of commercial moonshine; and to add that while chemical tests do exist to test for methanol in moonshine, most casual drinkers don't have these on hand while consuming these beverages.

• Why Does Alcohol Make You Sleepy, Then Alert?
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• What's Worse for Your Brain — Alcohol or Marijuana?

Originally published on Live Science.

Drinking a bottle of wine per week may be like smoking five to 10 cigarettes in the same time period, in terms of cancer risk, according to a new study from the United Kingdom.

The study, published today (March 28) in the journal BMC Public Health, is the first to estimate the "cigarette equivalent" of alcohol, with regard to cancer risk.

The researchers found that the increase in cancer risk tied to drinking one bottle of wine per week is equivalent to smoking five cigarettes per week for men and 10 cigarettes per week for women.

The goal of the research is to better convey the cancer risks that are tied to moderate alcohol consumption, which is generally thought to be less harmful than smoking cigarettes. Indeed, studies in both the U.S. and U.K. have found that many people aren't aware of alcohol's link to cancer. For example, a 2017 survey from the American Society of Clinical Oncology found that 70 percent of Americans didn't know that drinking alcohol is a risk factor for cancer.

"Our estimation of a cigarette equivalent for alcohol provides a useful measure for communicating possible cancer risks that exploits successful historical messaging on smoking," lead study author Dr. Theresa Hydes, of the Department of Gastroenterology and Hepatology at the University Hospital Southampton NHS Foundation Trust, said in a statement. "We hope that by using cigarettes as the comparator we could communicate this message more effectively to help individuals make more informed lifestyle choices." [7 Ways Alcohol Affects Your Health]

Dr. Richard Saitz, an addiction medicine specialist and chair of the Department of Community Health Sciences at Boston University School of Public Health, said that the study's comparison makes sense.

"I think it's about time that we communicate the cancer risks of alcohol — it's really been under the radar [and] this way is a good way to do it," said Saitz, who wasn't involved with the study.

Still, the researchers stress that the study isn't saying that moderate alcohol consumption is the same thing as smoking. The study only considered cancer risk, and not the risks of other health conditions, such as heart disease. In addition, the study looked at the lifetime risk of cancer in the general population, which might differ from an individual's cancer risk from either smoking or alcohol, the authors said.

Alcohol vs. cigarettes

To put alcohol's cancer risks in perspective, the study aimed to answer the question: In terms of cancer risk, how many cigarettes are in a bottle of wine? One bottle contains about 80 grams (2.5 ounces) of pure alcohol.

The researchers used national data from the U.K. on the lifetime risk of cancer in the general population as well as previously published research on the relationship between alcohol, smoking and cancer.

They estimated that, among nonsmokers, drinking one bottle of wine per week is tied to a 1.0 percent increase in lifetime cancer risk for men; and a 1.4 percent increase in lifetime cancer risk for women. In other words, if 1,000 men and 1,000 women each drank one bottle of wine per week, about 10 extra men and 14 extra women would develop cancer at some point in their lives, the researchers said. The higher risk among women is mainly due to the link between alcohol consumption and breast cancer.

This risk was comparable to smoking five cigarettes per week for men and 10 for women.

A "known carcinogen"

"Everybody knows that cigarettes cause cancer," Saitz told Live Science. "Hearing that some amount of alcohol is the equivalent of some amount of cigarettes" in terms of cancer risk, is helpful for the general public, he said.

Saitz noted that there's been little discussion of the cancer risks tied to alcohol, even though alcohol is a known carcinogen. Even dietary guidelines discuss the recommended number of alcoholic drinks per day.

"If I didn't call it alcohol or wine or beer or cocktails, and I just called it a carcinogen, no one would be talking about how many glasses of a carcinogen you could have," Saitz said.

The study authors noted that because the study only considered cancer risk, it didn't take into account other diseases tied to smoking or alcohol use, such as respiratory, cardiovascular or liver diseases.

The authors also pointed out that smokers typically consume far more than five to 10 cigarettes per week — the average smoker in the U.K. consumes around 80 cigarettes per week, and the average smoker in the U.S. consumes around 100 cigarettes per week.

Still, "these findings highlight moderate levels of drinking as an important public health issue," the authors concluded.

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Originally published on Live Science.

Alcohol consumption may be more harmful than thought, particularly for young and middle-age adults, a new study suggests.

Although drinking alcohol in moderation is often thought to be good for you, the authors point out that many studies on the benefits of alcohol consumption involve people ages 50 and older. This paints a skewed picture of the benefits of alcohol, because it eliminates people who have died from alcohol consumption at younger ages.

That's worrisome, because more than one-third of deaths from alcohol consumption occur among people ages 20 to 49, according to the study, published yesterday (Feb. 28) in the Journal of Studies on Alcohol and Drugs.

Indeed, "deceased persons cannot be enrolled in" medical studies, the study authors wrote. What's more, "those who are established drinkers at age 50 are 'survivors' of their alcohol consumption who [initially] might have been healthier or have had safer drinking patterns" compared with others, according to the study, led by Dr. Timothy Naimi, of Boston Medical Center's Clinical Addiction Research and Education Unit. [7 Ways Alcohol Affects Your Health]

The findings add to a growing body of research questioning the protective effects of alcohol consumption. Last year, a global study concluded that there is no safe level of alcohol consumption.

In the new study, the researchers analyzed information from a database that contains estimates of alcohol-related deaths and potential years of life lost due to alcohol consumption in the United States. The database includes 54 medical conditions that are related, either directly or indirectly, to alcohol consumption, such as alcoholic liver disease and alcohol-related car crashes. Though alcohol consumption is tied to an increased risk of death from most of these conditions, it's linked with a reduced risk of some others, mainly types of cardiovascular disease.

The study researchers found that from 2006 to 2010, about 36 percent of deaths related to alcohol consumption occurred in people ages 20 to 49, and 35 percent occurred among those ages 65 and older.

In addition, about 60 percent of years of life lost due to alcohol consumption occurred in people ages 20 to 49, compared with just 15 percent in people ages 65 and older.

To look at alcohol's benefits, the researchers focused on deaths that were estimated to be "prevented" by alcohol consumption, as well as years of life "saved" by alcohol. Only 4.5 percent of estimated deaths said to be prevented by alcohol consumption occurred among those ages 20 to 49, compared with 80 percent among those ages 65 and older.

More than 50 percent of the estimated years of life said to be saved occurred among those aged 65 and older, compared with just 14.5 percent of those ages 20 to 49.

Overall, the findings suggest that previous studies that enrolled older adults underestimated alcohol-related risks compared with what would be seen for drinkers of all ages, the researchers said.

Still, the researchers note that "there are many reasons why people choose to drink or not to drink alcohol apart from its health effects" and that most people who choose to drink moderately can do so with relatively low risk.

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Originally published on Live Science.

The adage, "beer before wine and you'll feel fine, wine before beer and you'll feel queer" doesn't hold up to scientific scrutiny. A new study finds that the order in which you consume alcoholic drinks won't actually help you avoid a hangover.

Rather, drinking too much alcohol of any kind — and in any order — will likely give you a hangover, the study researchers conclude.

"We didn't find any truth in the idea that drinking beer before wine gives you a milder hangover than the other way around," lead study author Jöran Köchling, of Witten/Herdecke University in Germany, said in a statement. "The truth is that drinking too much of any alcoholic drink is likely to result in a hangover." [11 Interesting Facts About Hangovers]

The study is published yesterday (Feb. 7) in the American Journal of Clinical Nutrition.

Putting proverbs to the test

There is no medically proven way to prevent or treat a hangover — the symptoms of headache, nausea and fatigue that come with drinking too much alcohol. Instead, people sometimes rely on such unproven folk sayings as "wine before beer"; or "grape or grain but never the twain"; or "beer before liquor, never been sicker." Similar folk wisdom on the ordering of wine and beer exist in other languages, including German and French.

The new study put these proverbs to the test. The researchers recruited 90 healthy volunteers ages 19 to 40 who agreed to down large amounts of alcohol, for science.

The participants were divided into three groups. The first group consumed about two and a half pints of beer (with an alcohol content of 5 percent each) followed by four large glasses of wine (with an alcohol content of 11 percent each). The second group consumed the same amount of alcohol, but in reverse order (wine followed by beer). The third group drank only beer or only wine. During the drinking task, the participants were asked to rate their perceived level of drunkness.

Afterwards, they spent the night at the study site under medical supervision. The next day, participants were asked about their hangover symptoms; and they were given a score based on the number and severity of those symptoms, such as thirst, fatigue, headache, dizziness, nausea, stomach ache, increased heart rate and loss of appetite.

A week later, the participants came back to the study site to perform the drinking task again, but participants in groups one and two were switched to the opposite drinking order. (Those who consumed beer first on the initial visit consumed wine first on the second visit, and vice versa.) Participants in the third group who drank only beer on the first visit drank only wine on the second visit, and vice versa. This way, the researchers could compare the reactions of each individual to the same person's earlier experience. (In other words, each person served as their own "control."

The researchers found that participants in all three groups had similar hangover scores.

"Unfortunately, we found that there was no way to avoid the inevitable hangover just by favouring one order over another," senior study author Dr. Kai Hensel, a senior clinical fellow at the University of Cambridge in the United Kingdom, said in the statement.

Only two factors predicted the severity of a person's hangover: that person's "perceived drunkenness" score and whether the person vomited after the drinking task. (Higher perceived drunkenness scores and vomiting were both tied to more severe hangovers.)

"The only reliable way of predicting how miserable you'll feel the next day is by how drunk you feel and whether you are sick. We should all pay attention to these red flags when drinking," Köchling said.

The researchers note that the study used only lager beer and white wine, so it's unclear if the results apply to other types of alcohol.

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Originally published on Live Science.

Archaeologists recently uncovered ancient storage rooms in a 2,000-year-old winery, at a site in Egypt's Nile Delta to the north of Cairo.

Inside these rooms — which appeared to be climate-controlled for keeping wine — archaeologists also found coins, pots used in winemaking and other pottery objects, said officials with the Ministry of Antiquities for the Arab Republic of Egypt (MOA), who shared the find in a Facebook post today.

The rooms were linked to a larger winery complex, which had already been partly unearthed during earlier excavations. Based on evidence gathered during this latest dig, experts suspect that there may be additional buildings nearby, which housed the winery's employees and their supervisors thousands of years ago, according to the Facebook post. [In Images: An Ancient Palace Wine Cellar]

The winery was built in what is now the Beheira governorate on Egypt's northern coast, during the Greco-Roman era — which lasted from the fourth century B.C. to the seventh century A.D., the Associated Press reported. During that time, this region of the Nile Delta was renowned for producing some of the finest wine in Egypt, Ayman Ashmawy, head of ancient Egyptian artifacts at MOA, said on Facebook.

Walls that made up the newfound storage chambers were thick and built from mud bricks; in some places, the walls incorporated limestone slabs of different sizes. This building technique probably helped to cool the chamber and regulate the temperature of the stored wine, Mostafa Waziri, general secretary of Egypt's Supreme Council of Antiquities, said on Facebook.

A set of kilns and assorted pottery artifacts associated with daily activities was found alongside coins that spanned centuries: from the time of Ptolemy I Soter, a successor of Alexander the Great who ruled Egypt from 323 B.C. to 285 B.C., to the Islamic conquest from A.D. 639 to A.D. 646, MOA reported.

Archaeologists also found painted shards that may have once covered a building's walls, as well as fragments of a mosaic layer that could have decorated the floor. These decorative elements hint at the presence of yet another building in the winery complex — possibly a residential structure for people who worked there, Ashmawy said.

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Originally published on Live Science.

There are all sorts of drinking traditions. Some people sing songs as they down their alcohol. Others dance to thumping music. Somewhere in the vicinity of Rotterdam, in the Netherlands, a group of young men, apparently inspired by the American television show "Jackass," got in the habit of capping off their boozing by swallowing live fish.

This, it turns out, is a bad idea. Especially in the event that the fish have evolved to fight back.

According to a recent case report published on Jan. 17 in the journal Acta Oto-Laryngologica Case Reports, the young men typically swallowed live goldfish out of their home aquarium — small, squishy creatures that don't put up much of a fight. The fun stopped on April 3, 2016, when one of the men tried to take their tradition a bit further by swallowing a bronze catfish (Corydoras aeneus), a popular aquarium fish with some powerful natural defenses. [27 Oddest Medical Case Reports]

Perhaps unsurprisingly, the night ended with the 28-year-old man in the emergency room, where puzzled doctors carefully removed the spiny fish from the man's throat.

"Most animals know better"

Most animals know better than to eat bronze catfish, said Kees Moeliker, a director at the Rotterdam Natural History Museum who reviewed the catfish remains after doctors removed them from the man's throat. That's for a good reason: Their cute 2- to 3-inch bodies (5 to 8 centimeters) are defended with spines, mounted on their pectoral fins. When the fish get stressed out — say, for example, when they're being swallowed by a predator — those spines become erect and can pump venom into the mouths of their attackers.

Because of this, bronze catfish "don't have predators like birds and other fishes," Moeliker told Live Science. "Those who give it a try die, and natural selection does its work."

Indeed, in the man's case, it appears that he quickly realized that he had made a grave mistake, according to a video of the incident that was described by the case report authors. Unfortunately, the video was not available for Live Science to review or share. But the report includes a vivid description of what it showed. In the video, a crowd of men stood around drinking and shouting "grote vis, grote vis!" (Dutch for "Big fish! Big fish!") One guy, holding a glass of clear water with the live catfish in it, tips it back, attempting to swallow it whole. Four seconds later, he spit the water and the fish out into his hands, and threw it on the table, where it floundered, appearing "distressed" and "agonized," according to the report.

That might have been the end of it, if someone hadn't plucked the flopping catfish off the table and handed it to a third man, a 28-year-old whose trauma would become the subject of the case report. This unfortunate fellow swallowed some beer, and then dropped the still-living creature into his throat. [11 Weird Things People Have Swallowed]

Immediately, it was obvious something had gone wrong. The man tried to swallow more beer but couldn't. Ten seconds later, he was "gagging vigorously" and vomiting liquid. "In extreme distress," he shoved two fingers down his throat, trying to make himself gag but no luck. Someone administered what the doctors described as a "wrongly-applied Heimlich maneuver," which again failed to produce the fish. The man spewed some blood into a bucket, and then the camera switched off.

Even so, the man apparently waited "several hours" before going to the hospital, after trying but failing to dislodge the fish with "more beer, honey and ice cream."

A "fish-like" structure

When the man finally made it to the emergency room, doctors looked down his throat using a tool called a laryngoscope, and spotted what they described as "a fish-like structure," according to the report. [Photos: The Freakiest-Looking Fish]

"This is definitely in the top three of weirdest medical cases I’ve encountered," said case report co-author Dr. Linda Benoist, a medical resident at Rotterdam’s University Medical Center who treated the patient. Benoist told Live Science that she had been aware that the fish-swallowing game was a "bizarre" tradition among some young people in the area.

The catfish, she said, was already dead when the patient arrived, pressed up against the entrance to the man's esophagus, at the bottom of his throat. (The fish had probably suffocated, Moeliker said, noting that a few swallows of beer do not contain enough water for a fish to breathe in).

The man needed surgery to remove the fish, with the surgeons paying very close attention to carefully remove the fish's spines from the delicate tissue in the throat. .

Fortunately, the procedure was a success. Though not much is known about the effects of bronze catfish venom on humans, it didn't appear to complicate the situation. As of the man's most recent follow-up with doctors, in March 2017, he is doing well.

The fish, meanwhile, ended up preserved at the Rotterdam Natural History Museum, which is right next door to the hospital. It joined an exhibit called "Dead Animal Tales" on dramatic collisions between animals and humans, Moeliker said.

Asked whether the drinking game is dangerous when only goldfish are involved, Benoist said, "I'm not an expert in goldfish swallowers, but I can imagine that fish species without [spikes] would slide easier into the stomach."

Still, the researchers did highlight some other case studies where people choked on live fish, including one instance where a fisherman attempted to kiss a fish but it slid into his throat. Live Science recommends eating fish dead and in bite-size pieces.

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Originally published on Live Science.

Smoking pot just once might be linked to changes in young brains, a new study suggests.

Adolescents who smoked marijuana one or two times had increased amounts of gray matter — a combination of neuron bodies and cells that feed them — in their brains compared with those who hadn't, according to a new study published yesterday (Jan. 14) in the Journal of Neuroscience.

A bigger brain volume may sound like a benefit for adolescents, but it may not be, said lead study author Catherine Orr, a lecturer in the department of psychological sciences at Swinburne University of Technology in Australia. [7 Ways Marijuana May Affect the Brain]

That's because, in adolescence, the brain typically undergoes a process called pruning, Orr said. During this process, which goes on through a person's early 20s, the brain chips away at its existing gray matter, and increases the amount of white matter, which consists of the long tails of neurons called axons that connect cells, and their protective coating called myelin.

Though it’s not absolutely clear why the brain does this, the best explanation to date is that the process makes the brain more efficient, cutting away unnecessary or redundant components, and also makes the brain more complex by building more connections, Orr said.

That's why interfering in the process — by adding more gray matter — could potentially be a bad thing.

Measuring gray matter

In their study, Orr and her team looked at brain scans from 46 teens, all age 14, from Ireland, France, England and Germany. Some reported having smoked marijuana once or twice while others reported never having used the drug at all. The researchers controlled for other factors such as cigarette smoking and alcohol-use that could have also driven these changes.

The study found that those who smoked pot had higher volumes of gray matter in areas of the brain that had cannabinoid receptors, compared with those who reported never using the drug. Compounds in marijuana bond to cannabinoid receptors, which are found in areas including the amygdala (which is involved in emotion and threat processing), the hippocampus (which is involved in memory and learning), and the nucleus accumbens (which is involved in reward and addiction).

The researchers also found that those who had increased gray matter in their brains also had lower perceptual reasoning and a lower ability to perform a task quickly than those with normal levels of gray matter

"I personally was surprised at how extensive the effects were," Orr told Live Science.

Previous studies had found marijuana affects similar areas of the brain, however, these studies have had inconsistent results. For example, some studies in adults have found that marijuana-use was linked to an increase in gray matter, while others found the opposite. Orr noted that because these earlier mostly looked at adult brains, it's difficult to untangle the potential effects of other substances such as alcohol.

Even so, increasing evidence shows that adults that use marijuana at higher rates or for longer amounts of time or those who started earlier in life showed greater changes in the brain, she said.

Still, Orr said that more research is needed to say for sure what the effects of marijuana are on the brain. The small sample size of the study makes it difficult to disentangle the effects that other activities may also have on the brain, she added.

It's also unclear whether these changes in the brain are long-lasting, Orr said, adding that it would be good to do a follow-up study to explore this question. Ultimately, the researchers hope to be able to "identify which people are more at risk of these brain-based effects and [let] people know what [these effects] are," Orr said.

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Originally published on Live Science.

The first human colonists on Mars will have to forgo many of the creature comforts of Earth — things like enjoying an ozone layer, for example, or opting out of rearing genetically engineered Martian babies. Fortunately, one essential earthly amenity these hardscrabble colonists may not have to give up is wine.

Georgia, a country with an 8,000-year-old viticulture tradition, is putting its top space and wine scientists to work figuring out how to grow grapes on Mars.

The project, named IX Millennium, ostensibly as a nod to Georgia's ninth millennium making wine, will involve several phases of research into building an agricultural infrastructure on Mars. One critical step: identifying the grape varietals on Earth best equipped to withstand the harsh radiation, fearsome dust storms and severe temperature swings of the Red Planet. This research could help hydrate permanent settlements on Mars a soon as 2024 — the year when SpaceX founder Elon Musk intends to launch the first crewed mission there. (NASA hopes to follow in the 2030s.) [Mars InSight Photos: A Timeline to Landing on the Red Planet]

"If we're going to live on Mars one day, Georgia needs to contribute," Nikoloz Doborjginidze, founder of Georgia's Space Research Agency and an adviser on the wine project, told The Washington Post. "Our ancestors brought wine to Earth, so we can do the same to Mars." (The origins of wine are still debated, but Georgia holds a valid claim thanks to their recent discovery of an old wine-stained pot dated to 6000 B.C.)

The first wine on Mars

The new space wine project will kick off later this year with the installation of "vertical greenhouses" inside a hotel in the capital city of Tbilisi, according to Georgian news agency Agenda.ge. There, floor-to-ceiling pods of soil and seeds (including grapes, strawberries and arugula) will be left to grow under hydroponic lights with minimal human interference, simulating the possible conditions of a controlled agriculture pod on Mars.

In the meantime, Georgian wine experts are hard at work trying to figure out which grape varietals might best survive harsh Martian conditions. Over the next few years, researchers at Tbilisi's Business Technology University plan to simulate a Martian environment in the laboratory, exposing soil samples to subzero conditions, high carbon monoxide levels and thin air meant to mimic the atmospheric pressure at "20,000 feet [6,000 meters] altitude on Earth," The Washington Post reported.

These experiments likely will not bear fruit until at least 2022, but scientists already have a hunch that white wine will fare best on the Red Planet.

"Whites tend to be more resistant to viruses," Levan Ujmajuridze, director of Georgia's vineyard Laboratory, told The Washington Post. "So, I'd imagine they'll do well against radiation, too. Their skin could reflect it."

These experiments could well provide future Martians with grapevines — but the actual fermenting, bottling and aging would be up to them. Nobody knows exactly how fermenting grapes in microgravity will actually work yet, but NASA scientists think it's possible.

The Georgia team's boozy experiments aren't the first foray into space agriculture. Astronauts aboard the International Space Station (ISS) have already begun growing salad crops in microgravity, while China's recently deployed Chang'e-4 lander will attempt to grow potatoes and rockcress (a flowering plant similar to cabbage and mustard) on the moon.

The makers of Budweiser, meanwhile, have launched barley seeds into space three times in hopes of becoming "the first beer on Mars," while a batch of Ardmore scotch whisky spent three years aboard the ISS from 2011 to 2014. That project showed Earthlings that even an old drop of the pure is apparently not immune to the ravages of microgravity; the scotch reportedly came home tasting of "antiseptic lozenges" and "rubbery smoke."

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Originally published on Live Science.

It may sound counterintuitive, but people who are supersensitive to coffee's bitter taste actually drink more of it, a new study finds.

This sensitivity isn't simply a matter of taste, either, but rather is influenced by a person's genetic makeup, the researchers said in the study, which was published online today (Nov. 15) in the journal Scientific Reports.

"You'd expect that people who are particularly sensitive to the bitter taste of caffeine would drink less coffee," study senior researcher Marilyn Cornelis, an assistant professor of preventive medicine at the Northwestern University Feinberg School of Medicine in Chicago, said in a statement. "The opposite results of our study suggest coffee consumers acquire a taste [for] or an ability to detect [the bitterness of] caffeine due to the learned positive reinforcement elicited by caffeine." [10 Things You Need to Know About Coffee]

Put another way, people who have a heightened ability to taste the bitterness of coffee, and especially the distinct bitter flavor of caffeine, learn to associate "good things with it," Cornelis said. This finding is surprising, given that bitterness often serves as a warning mechanism to convince people to spit out harmful substances, the scientists said.

Researchers conducted the study to understand how genetics influences people's consumption of tea, coffee and alcohol, which tend to taste bitter, said lead study researcher Jue Sheng Ong, a doctoral student in the Department of Genetics and Computational Biology at the QIMR Berghofer Medical Research Institute in Brisbane, Australia.

"While all bitter flavors might seem the same, we perceive the bitterness of Brussels sprouts, tonic water (quinine) and caffeine separately," Ong told Live Science. "The degree to which we find these flavors bitter is, in part, determined by your genes."

To investigate, the researchers looked at the genetic makeup and daily bitter-beverage consumption of more than 400,000 people from the United Kingdom. "Using the genes related to our ability to taste bitterness, we were able to assess whether those that have a higher genetic predisposition to tasting bitterness are more likely to prefer tea over coffee," Ong said.

The results showed that people with the genes to taste the bitterness of green vegetables (such as Brussels sprouts) or tonic water are more likely to prefer tea over coffee, the researchers found. In addition, people who were more sensitive to quinine's bitter flavors and those found in green vegetables tended to avoid coffee.

Meanwhile, people with the genes to taste the bitterness in Brussel sprouts were less likely to drink alcohol, especially red wine, than people without those gene variants, the researchers found. This insight may help scientists studying addiction, Ong said.

Ong noted that the researchers didn't look at flavorings, such as cream or sugar, that people sometimes pour into coffee to temper its bitterness. "One can imagine that, at a personal level, there are a lot of factors that determine a person’s coffee intake — socioeconomic status, ability to metabolize caffeine and smoking," he said. "On top of that, people drink all sorts of coffee — black coffee, flat white [and] cappuccino." So, the researchers chose to look for big trends in how genes relate to bitter-beverage consumption, he said.

"[The results] suggest that perhaps most types of coffee still share very similar bitter-taste profiles," Ong said.

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Originally published on Live Science.

The world's oldest beer may have been brewed for a funeral 13,000 years ago.

At a graveyard cave in Israel, archaeologists discovered traces of mashed wheat and barley lining pits carved into the bedrock. The researchers interpreted these residues as leftovers from beer brewing, perhaps part of a funerary feast.

"This accounts for the oldest record of man-made alcohol in the world," Li Liu, a professor of Chinese archaeology at Stanford University, said in a news release.

Liu's team had been trying to learn about ancient diets from plant residues on the stone pits found in the Raqefet Cave, a Natufian grave site near Haifa, Israel. [Raise Your Glass: 10 Intoxicating Beer Facts]

The Natufians were a Stone Age culture that lived in the Near East from around 15,000 to 11,500 years ago. They established some of the earliest settlements in the world and may have been among the earliest people to domesticate plants and animals.

At Raqefet Cave, Liu's team collected residue samples from the stone pits, or mortars that had been dug into the cave. Under a microscope, they saw damaged-looking starch granules, thought to be from wheat or barley that was malted and mashed during beer brewing.

To test this hypothesis, the researchers conducted experiments to look at how starch granules transformed during the brewing process. To re-create Natufian-style beer, they turned barley into malt, which they mashed and heated and left to ferment with yeast. Under the microscope, the modern starch granules matched the ones found at Raqefet Cave, Liu and her colleagues reported in the Journal of Archaeological Science: Reports.

"I thought [the study] was pretty exemplary in terms of the procedures and techniques," said Brian Hayden, an archaeologist at Simon Fraser University in Canada who was not involved in the study, but reviewed the paper before publication. "They show that in the brewing process, the starch grains undergo some morphological changes."

Hayden told Live Science that there has been considerable debate among archaeologists about the nature of the Natufian culture and other complex hunters and gathers of the same period. He's argued that this was a society with surpluses, wealth, social inequality and extensive trade networks —and finding evidence for brewing helps support that point of view.

"Brewing by itself indicates that this is a society with surpluses," Hayden told Live Science. "A lot of the residual material from brewing is discarded."

He added that there is evidence for feasting in the Natufian culture, and ethnographic evidence suggests that feasting for many traditional societies involves making alcohol.

"We were predicting that eventually somebody would find the smoking brew pot and demonstrate that there was brewing in the Natufian," Hayden said.

Pat McGovern, a biomolecular archaeologist at the University of Pennsylvania Museum of Archaeology and Anthropology, has also been waiting for evidence of alcohol consumption from the Paleolithic period, or Old Stone Age, which he calls the "Holy Grail" in his book "Ancient Brews" (W. W. Norton & Co., 2017).

"The earliest evidence we had for ancient beverages until now was from the Neolithic period," McGovern told Live Science. "I believe that this article is on the right track in finding out more about fermented beverages during 99 percent of humankind's history, dating back millions of years."

McGovern does, however, think the starch analysis could be strengthened by further chemical and pollen studies. "It would be good to have additional verification by different methods of the ingredients that were used, and of the mashing or fermentation process," he said. "I'm not totally convinced, but I think it was highly probable that people were making a fermented beverage in this period, and that it was used for religious burial practices."

The findings at Raqefet Cave might also add to the debate over whether a thirst for beer or a hunger for bread may have driven people to domesticate grain. In July, another group of archaeologists working at a Natufian site in east Jordan reported that they found the earliest evidence of bread making — 14,000-year-old traces of charred flatbread made from wild grain.

Original article on Live Science.

We all know we shouldn't drink and drive. But what about hopping behind the wheel the morning after you've been drinking? According to a new meta-analysis, even this could be problematic, as the effects of alcohol on our brains may linger even after the chemical has left our bloodstream.

The meta-analysis, which was published Aug. 25 in the journal Addiction, found that a night of heavy drinking may affect people's cognition the next day, including their memory, attention, coordination and even driving skills.

"Our findings demonstrate that [having a] hangover can have serious consequences for the performance of everyday activities such as driving, and workplace skills such as concentration and memory," senior study author Sally Adams, an assistant professor in the Department of Psychology at the University of Bath, in the United Kingdom, said in a statement.

Thinking after drinking

It's well-known that drinking alcohol can temporarily impair thinking and coordination while a person is intoxicated. But whether drinking alcohol impairs cognition the next day — i.e., when a person is  hungover — is less clear, with studies on the topic finding conflicting results. [11 Interesting Facts About Hangovers]

In the meta-analysis, the researchers analyzed data from 19 previous studies involving more than 1,100 people. All of the studies tested people's thinking abilities the day after they had drunk heavily, when their blood-alcohol level was less than 0.02 percent. (For comparison, the legal blood-alcohol limit for driving a car in the United States is 0.08 percent.)

Some of the studies were conducted in a laboratory — meaning that researchers gave people precise amounts of alcohol before testing their thinking abilities; other studies were "naturalistic," meaning that researchers told people to come to the lab after a typical night of social drinking.

The study found that, overall, people who were hungover had poorer attention, memory and coordination skills, compared with those who weren't hungover. A few of the studies tested people's driving ability using a driving simulation. The studies found that when people were hungover, their ability to control a vehicle was impaired, compared with when they were not hungover.

Although many people think that it's fine to drive the morning after a night of drinking, "it might be that we're still impaired the next day, even after the alcohol has left our system," Adams said.

Overall, the findings suggest that "some of the things that you might expect to happen with your thought processes on alcohol may continue throughout into the hangover period," said lead author Craig Gunn, also of the University of Bath's Department of Psychology. This means that if you're a student attending a lecture, you might not be able to remember things as well when you're hungover, compared with when you're not hungover, Gunn said. And if you're driving a car, you might not be able to react as efficiently to a red light, he said.

Still, the researchers noted that some of the studies did not take into account other factors that could affect thinking abilities, such as smoking or sleep deprivation. The researchers called for further studies testing the effects of alcohol on cognition, particularly on people's "executive functions," which include decision-making and problem solving.

More research is also needed on the effect of hangovers on workplace safety and productivity, the researchers said. They noted that although many workplaces have policies prohibiting intoxication on the job, few of these policies cover the next-day effects of alcohol.

Original article on Live Science.

Drinking alcohol in moderation is more harmful than previously thought, according to a new study that concludes there's no "safe" level of alcohol consumption.

The comprehensive study, which analyzed information from millions of people in nearly 200 countries, found that alcohol is tied to nearly 3 million deaths globally each year, with about 1 in 10 deaths linked to alcohol use among people ages 15 to 49.

What's more, any protective health effects of alcohol were offset by the drink's risk, including strong links between alcohol consumption and the risk of cancer and injuries such as those resulting from car accidents. [7 Ways Alcohol Affects Your Health]

"The widely held view of the health benefits of alcohol needs revising," the researchers wrote in their paper, published online Aug. 23 in the journal The Lancet. "Our results show that the safest level of drinking is none."

The findings contrast with most health guidelines, which say that moderate drinking — about one drink a day for women and two for men — is safe.

However, it's difficult to estimate the risks for a person who drinks fairly infrequently — such as someone who has one drink every two weeks — so the findings might not apply to this population. "[It] doesn't mean, if you drink on birthdays and Christmas, you're going to die," said Keith Humphreys, a professor of psychiatry and behavioral sciences at Stanford University who was not involved in the study.  

Rather, the findings apply more to people who have one drink a day, most days of the week, Humphreys said. Contrary to what some previous studies have found, "the kind of person who drinks every week, but never drinks much, is in fact not better off than somebody who doesn't drink," according to the new study, Humphreys told Live Science.

No "safe" level

The study analyzed information from nearly 700 previous studies to estimate how common drinking alcohol is worldwide, and examined almost another 600 studies including a total of 28 million people to investigate the health risks tied to alcohol.

The researchers found that, globally, about 1 in 3 people (32.5 percent) drink alcohol, which is equivalent to 2.4 billion people worldwide, including 25 percent of women and 39 percent of men.

Worldwide, drinking alcohol was the seventh-leading risk factor for early death in 2016, accounting for about 2 percent of deaths in women and 7 percent of deaths in men. For people ages 15 to 49, alcohol consumption was tied to 4 percent of deaths for women and 12 percent for men in 2016.

The study found that moderate drinking was, in fact, protective against ischemic heart disease. But this benefit was outweighed by the health risks of alcohol.

Specifically, for people who consume one drink a day, the risk of developing one of 23 alcohol-related health problems increases by 0.5 percent over one year, compared with someone who doesn't drink.

But the risk increases rapidly the more people drink. For people who consume two drinks a day, the risk of developing one of the 23 alcohol-related health problems increases by 7 percent over one year, and for those who drink five drinks a day, the risk increases by 37 percent over one year. [Top 10 Leading Causes of Death]

"Alcohol poses dire ramifications for future population health in the absence of policy action today," Emmanuela Gakidou, a professor of global health at the University of Washington's Institute for Health Metrics and Evaluation and a co-author of the study, said in a statement.

The researchers said that, based on their results, public health campaigns should consider recommending abstinence from alcohol.

Alcohol abstinence?

Humphreys called the work the "most sophisticated global study of the impact of alcohol on human health ever conducted."

"The study confirms that alcohol is one of the world's leading causes of disability, disease and death," Humphreys said.

However, in terms of recommending abstinence from alcohol, Humphreys said that promoting such a message would be difficult, in part because of the large number of people who currently drink alcohol and the influence of powerful industries in the alcohol market. "I'm not saying it's a terrible idea," Humphreys said, but "it would be a very tough uphill battle to be established."

Still, in addition to considering abstinence, the researchers called for other policies that focus on reducing the population's consumption of alcohol, such as increasing alcohol taxes, controlling the availability of alcohol and the hours it can be sold, and regulating alcohol advertising. "Any of these policy actions would contribute to reductions in population-level consumption, a vital step toward decreasing the health loss associated with alcohol use," Gakidou said.

The study was funded by the Bill & Melinda Gates Foundation.

Original article on Live Science.

Following the 2011 Fukushima nuclear power plant accident, radioactive waste leaked into surrounding areas and contaminated waters and food. Seven years later, traces of the disaster were found half a world away — in California's wine. 

A group of French nuclear physicists tested 18 bottles of California's rosé and cabernet sauvignon produced in 2009 and onward and found that the wines produced after the disaster had increased levels of a man-made radioactive particle. Cabernet sauvignon, for example, had double the amount. [Tracking Japan's Tsunami Debris (Infographic)] 

They reported their findings in the pre-print online journal Arxiv.

The researchers used two methods to look for traces of a radioactive isotope called cesium-137. The first method was developed about 20 years ago and could detect the particles through the wine bottle, without destroying or opening it. Since the presence of cesium-137 prior to 1952 is impossible (it's a man-made isotope first released into the surroundings by nuclear testing in the mid-20th century), it has proven quite effective for detecting fraud in old vintage wines, according to the study.

For a more accurate detection, the researchers destroyed the wines through heating and reducing them "to ashes," they wrote. They tested for the cesium-137 in those ashes.

Though they did find increased levels of the radioactive waste, experts say there is nothing to worry about, according to The New York Times. There are no "health and safety concerns to California residents," the California Department of Public Health told the Times.

The levels of radioactive toxins found in food and drinks outside of Japan is too low to be dangerous, according the World Health Organization.

Even in Japan at the core of the meltdown, though over 100,000 people were evacuated from their homes, there have been no deaths or radiation sickness reported so far, according to the World Nuclear Association. Further, most bottles of wine made after 1952 do contain at least a little bit of this nuclear twist. 

Originally published on Live Science.

New mothers are commonly heaped with advice — some of it welcome, some not. But there's one rather unconventional piece of wisdom that stands out from the rest: For decades, women have been told they should drink Guinness — the dark, Irish beer — to boost their production of breast milk and nourish their newborns. To Guinness lovers, this might be a welcome nugget of advice. But does it stand up to scientific scrutiny?

One thing we do know is that the idea has roots deep in history, long before Guinness came along. In fact, humans have been touting the milk-boosting benefits of beer for centuries. As far back as 2000 B.C., records apparently show that the Sumerian people prescribed beer as an aid for breast-feeding. Along with many other foods — like anise, fenugreek (an herb) and oatmeal — beer developed a reputation as a "galactagogue," a food thought to stimulate lactation. Over the centuries, this became an established belief in traditions around the world.

"It's cross-cultural," said Maija Bruun Haastrup, a clinical pharmacologist at Odense University Hospital in Denmark. "Something I find very interesting is that we have this same old-wives tale everywhere."[Does Mom's Drinking Harm Breastfed Babies?] 

In the early 1900s, the marketing campaign around Guinness, in particular, gave it a special identity as a "healthful" beverage. Because the beer initially was manufactured with a kind of yeast that gave it a high iron content, it was reportedly offered to blood donors back in the day, or to patients who had just undergone surgery in the hospital. This helped to solidify the drink's original slogan: "Guinness is good for you." Nursing mothers were then encouraged to imbibe this drink as a milk-boosting tonic, too.

While we now know that the campaign around this beverage may have overstated its benefits at the time, Haastrup said there is some scientific truth to the idea that beer boosts breast milk.

"It's important to emphasize that the amount of research here is quite limited," she cautioned. But some studies have drawn a link between a polysaccharide, a type of carbohydrate present in barley hops, and an increase in prolactin, the hormone that aids the production of milk from breast tissue. These factors might explain why beer drinkers of the past sensed that the beverage had a beneficial effect on their capacity to produce milk.

But there's a caveat: Adding alcohol to this hoppy mixture obscures any potential benefit one might get from the barley. Gary Beauchamp and Julie Mennella, two biopsychologists at the Monell Chemical Senses Center in Philadelphia, carried out landmark research in the 1990s showing that when mothers consume alcohol and breast-feed, it seems to alter the flavor of their milk, causing infants to feed less over a certain period of time.

"Essentially, the hypotheses are that the alcohol is affecting either the infant or the mother," Beauchamp, now emeritus director of the Monell Chemical Senses Center, told Live Science.

In a meta-analysis of more than 40 papers, Haastrup identified another pattern in the research, highlighting how alcohol impacts the way the body discharges milk. Breasts release milk through a reflex known as the "letdown," which is triggered by a hormone called oxytocin, Haastrup said.

"Oxytocin is extensively inhibited by alcohol," she said. "So if you ingest alcohol, your oxytocin production is reduced, which leads to a delayed milk letdown reflex." [Why Do Some People Hate the Taste of Beer?]

What can this research collectively tell us about breast-feeding and booze? On one hand, Beauchamp said, "I think it is important for [mothers] to know that the still-prevalent idea that alcohol consumption somehow enhances breast-feeding has no scientific basis."

On the other hand, Haastrup believes that moderate alcohol consumption is less of a hindrance to milk production than it may appear at first. The letdown seems only to be delayed by alcohol, not entirely stopped, she said. Studies have found that babies nursing from mothers who've consumed an alcoholic drink will still feed as much over a 16-hour period as babies whose mothers haven't imbibed at all.

"There isn't a direct inhibition of milk production caused by alcohol, but it makes it a bit more difficult to start breast-feeding," Haastrup told Live Science.

So, what's the verdict for Guinness? It seems that drinking it to enhance breast-milk production probably isn't the best course of action. For that, alcohol-free beers — with all their barley-rich goodness — might be a better bet. "That's why, in maternity wards in Denmark, they actually recommend alcohol-free beer," Haastrup said. "This is something we've known for ages."

But breastfeeding aside, if a nursing mother just feels like having a pint to pass the time while her baby feeds, Haastrup said there's no reason why she shouldn't.

"As far as I can see, there isn't a problem here as long as you follow the general recommendations, only drink occasionally, and drink responsibility," she said. For instance, the American College of Obstetricians and Gynecologists says that a nursing mother would be wise to wait for two hours after an alcoholic drink, before she feeds her infant again. And sure, the alcohol could trigger a temporary delay in milk production — but then, that might just be worth it for the chance to kick back with the occasional beer.

Original story on Live Science.

When grape harvesters at a German winery mysteriously fell ill with "rabbit fever," a rare bacterial illness, one question in particular stood out: How did they get sick?

After a lengthy investigation, officials had an answer: It was the grapes.

Rabbit fever, or tularemia, is a serious illness caused by the bacterium Francisella tularensis, which infects animals such as rodents, rabbits and hares, according to the U.S. Centers for Disease Control and Prevention (CDC). It's rare in the United States, with only a few hundred cases reported per year, and also rare in Germany. People can contract the disease through tick bites, from handling infected animals or by consuming contaminated food or water. [10 Bizarre Diseases You Can Get Outdoors]

In the German cases, which occurred in October 2016 in the southwestern state of Rhineland-Palatinate, six harvesters became ill, with symptoms including fever, chills, difficulty swallowing, swollen lymph nodes and diarrhea, according to a new report of the outbreak published Wednesday (July 11).

The workers tested positive for F. tularensis, and their symptoms suggested they had become ill from eating or drinking something contaminated with the bacteria, not from a tick bite. (When people get tularemia through tick bites, they usually develop skin ulcers at the site of the bite, where the bacteria entered the body, according to the CDC.)

What's more, the workers didn't have any of the typical risk factors for the disease, such as having hunted or eaten infected animals, the report said.

So, health officials conducted a study to figure out which activities at the winery were linked with the illness. They found that, compared with workers who didn't get sick, those who developed tularemia were much more likely to have engaged in one particular activity: drinking "grape must," or juice from crushed grapes that contains the skin, seeds and stems. (Preparing grape must is one of the first steps in winemaking.)

In particular, the workers who got sick drank grape must made from a batch of grapes that had been harvested by a machine, rather than picked by hand.

The researchers found genetic traces of F. tularensis bacteria in the unfinished wine made from this machine-pressed grape must, the report said.

"To our knowledge, [this] is the first outbreak of tularemia linked to grape must," said senior author Dr. Philipp Zanger, an infectious-disease specialist at University Hospitals in Heidelberg, Germany, and an epidemiologist at the Federal State Agency for Consumer and Health Protection in Rhineland-Palatinate.

The researchers also found genetic traces of field mice in the unfinished wine made from the grape must. They suspect that an infected mouse may have been collected by the mechanical harvester and pressed with the grapes.

"This outbreak suggests that mechanical harvesting can be a risk factor for the transmission of zoonoses [diseases from animals] such as tularemia," the report said.

Zanger told Live Science that the report highlights the need to be cautious when consuming raw, untreated food products like grape must.

But what about the wine? Zanger said that, based on experiments that he and his colleagues conducted, there's no evidence that tularemia bacteria can survive in finished wine products. But as a precaution, the contaminated products at this winery were confiscated, and their sale was prohibited, the report said.

Original article on Live Science.

If the thought of sipping a beer is gag-inducing, you're not alone. But even if you're in good company, it begs the question: Why do some people hate the taste of beer?

The answer comes down to genetics, which influences how our brains process bitter-tasting and cold beverages.

What's more, it turns out that beer's bitter taste triggers evolutionary wiring designed to keep us away from potentially dangerous food and drink, and this trigger is stronger in some people than it is in others. [Is Booze Tasty or Bitter? Your Genes Decide]

But first, let's start with beer's bitter taste. As you may remember from science class, there are five types of taste cells within our taste buds that help us perceive salty, sweet, sour, umami (savory) and bitter flavors. Once the taste buds identify specific flavors, taste receptors send this data via nerves to the brain stem.

"If you think of a receptor as a lock, then whatever it binds to is a specific key," Dr. Virginia Utermohlen Lovelace, an associate professor emeritus of nutritional sciences at Cornell University in Ithaca, New York, told Live Science. "The cell to which that receptor is attached sends a message to the brain to say, 'Oooh this is bitter!'"

There are a whopping 25 different types of taste receptors for bitterness in the human body. In comparison, there are only two different kinds of salt receptors. Meanwhile, beer's bitterness largely comes from hops. The alpha and beta acids found in hops, as well as the low concentrations of ethanol in beer, bind to three of these 25 bitter receptors, signaling a strong bitter taste to the brain when you take a sip of lager, Lovelace said.

But what makes bitter flavors hard to swallow? The next time your friends delight in introducing you to a new craft IPA, you can tell them that their singular tastes are in direct opposition to evolutionary instinct. Humans actually evolved bitter taste receptors for our own safety — to identify poisonous foods that could be harmful.

"Bitter taste is considered a warning system for poisoning," researchers in a 2009 study published in the journal Chemosensory Perception concluded. "Many toxic compounds appear to taste bitter; yet, toxicity seems not to be directly correlated with the taste threshold concentrations of bitter compounds," the researchers said.

In other words, just because something tastes bitter and makes you wince, that doesn't automatically mean that beer (or any other bitter food or beverage) is out to kill you.

This brings us to the science behind genetic functional polymorphisms, also known as genetic variations. Since there are so many taste receptors for bitterness, it's safe to say that bitter flavors — how we perceive them and how much we can tolerate them — have a plethora of inheritable genetic possibilities.  

According to a 2017 study published in the journal Scientific Reports, TAS2R16 alone (which is one of the 25 bitter receptors in the human body) has 17 polymorphisms, including a variant that is associated with alcohol dependence.

Lovelace explained that one of the easiest indicators of bitter sensitivity is the number of taste buds you have in your mouth. The more taste buds you have, the more likely you are to detest hoppy beers.

Bitter receptors, however, are not the only variants at play. The carbonation in beer turns on our "cold" receptors (the same temperature receptors that make minty gum taste cold and cinnamon taste hot). Cold receptors have genetic variations too, so while you may not be sensitive to the bitterness of beer, the receptors that signal coldness might also make beer seem unappealing, Lovelace said.

If you're sensitive to the bitterness in beer or other alcohol, there are countermeasures to help "drown out" the strength of the bitter receptors, she noted.

"Sweet and salty foods can help turn off the effects of the bitter receptors, which is why we have beer nuts and why we drink tequila with salt!" Lovelace said. "When you cut away the bitter, you're more likely to receive the specifics of the flavors underneath."

Original article on Live Science.

Forget the conundrum of whether your glass is half-empty or half-full — pretty soon, plenty of beer glasses in the United Kingdom may not have anything in them at all.

Soda drinkers won't have much to toast with, either. And it's all due to a severe disruption in the European supply chain of industrial, food-grade carbon dioxide (CO2), the gas that lends the beverages their fizz, gas industry website Gasworld reported on June 19.

The CO2 shortage isn't just affecting beverages — it's also serving up a generous helping of trouble for meat production in Europe. Carbon dioxide is used in meat packaging to slow the growth of microbes and preserve the meat's color and freshness, and in slaughterhouses, CO2 is used to stun animals prior to killing them, representatives of the British Meat Processors Association (BMPA) reported in a statement released June 21. [Raise Your Glass: 10 Intoxicating Beer Facts]

The trouble began with the recent closure of several industrial plants that provide liquid CO2 across northern Europe; they were shuttered "for various reasons, including maintenance and refurbishment," affecting a number of businesses that produce or distribute food and beverages, Gavin Partington, director general at the British Soft Drinks Association, said in a statement on June 20.

BMPA officials reported on June 21 that the CO2 shortage would likely last "approximately four weeks." In the days that followed, the flow of CO2 across northern Europe slowed to a trickle, with the U.K. the hardest hit by the CO2 scarcity. On June 26, a widely used British wholesale food and beverage company began rationing distribution of carbonated drinks, restricting businesses' purchases to no more than 10 cases of beer and a maximum of five cases of cider or soda, CNBC reported.

Meanwhile, concerns were growing that meats, beer and carbonated beverages would disappear from British supermarket shelves "if a normal supply of CO2 is not restored as quickly as possible," Ian Wright, a representative of the U.K.'s Food and Drink Federation (FDF) said in a statement released June 29.

A purified gas

CO2 that puts the fizz in your beer and soda is fundamentally the same as CO2 in Earth's atmosphere, but it must be food-grade quality. In other words, to be used in food or drink, CO2 has to be purified according to local regulations and standards, and then shown to be free of contaminants, chemist and American Chemical Society member Richard Sachleben told Live Science.

This CO2 is typically produced as a byproduct of industrial or chemical manufacturing processes, such as those used in ammonia plants. It is dissolved in liquid in sealed containers under high-pressure conditions, Sachleben explained. Once the CO2 is sealed up, it has nowhere to go until the container is opened, which is why you see fizz rising in a bottle after you open the cap and release the pressure inside, enabling the CO2 to convert to gas and escape, he said.

"As long as you maintain the pressure, carbon dioxide will stay in the liquid — if you release the pressure, it'll release into the atmosphere," Sachleben said.

But in case you're wondering if the U.K. and the rest of Europe could get some relief from the CO2 shortage by siphoning CO2 from the atmosphere — that wouldn't be a practical solution, Sachleben told Live Science.

Even with rising levels of atmospheric CO2 due to climate change, CO2 in the air is still only about 400 parts per million, and is mixed with nitrogen, oxygen and other elements. It would therefore be quite a costly and time-consuming challenge to extract and refine purified CO2 from air — at least in the amounts that are typically collected from industrial processes, he said.

Original article on Live Science.

Drinking less alcohol may be linked to a lower risk of cancer, a new study suggests.

In the study, researchers found that people who drank some alcohol had a lower risk of cancer and death from any cause during a nine-year period than those who drank more or none.

In particular, people who had fewer than seven drinks a week had the lowest risk of cancer and death, compared with those who had seven or more drinks a week, according to the study, published today (June 19) in the journal PLOS Medicine. And with each additional drink a week, the risk of cancer and death from any cause increased, the scientists reported.

However, the study found only an association between alcohol and cancer and death, and did not prove cause and effect, the researchers said.

What sets the new study apart, said lead study author Andrew Kunzmann, a postdoctoral research fellow at Queen's University Belfast in Ireland, is that previous studies have tended to look at cancer and mortality separately. [7 Ways Alcohol Affects Your Health]

"That tends to give very different messages about what the role of alcohol and health is," Kunzmann told Live Science. Most existing evidence suggests that light-to-moderate drinkers had the lowest risk of dying from various causes during the study period, yet "never drinkers" had the lowest risk of developing cancer, he said.

"What our study does is combine the two outcomes together and [finds] that lighter drinking is associated with the lowest risk of cancer or death," Kunzmann said. And those who had no drinks or more than one drink a day were more at risk for death or cancers, most commonly esophageal and liver cancer and cancers of the head or neck regions, Kunzmann said.

In the study, the team analyzed data about lifetime alcohol use from questionnaires that were given to the nearly 100,000 participants in the United States between 1998 and 2000. The questionnaires were given at the beginning of the study and asked how many drinks a person had a week at present and with what frequency over the previous year. The researchers also looked at data on the number of primary cancer diagnoses (meaning it was the first time the person had been diagnosed with cancer) and deaths that occurred in the cohort over the next nine years.

"The study results suggest that minimizing alcohol intake may help individuals who already drink to lower their risk of developing certain types of cancer, such as breast, colorectal and liver cancer," Kunzmann said in a statement. "The results perhaps also suggest that [decisions about] drinking that second glass each night shouldn't be made for health reasons."

But Kunzmann noted that the participants were all older adults. That means that "we're not really reflecting what happens in younger people if they drink," he said. Also, it's difficult to account for other lifestyle factors that could have affected the results.

"Light drinkers tend to be more wealthy or lead healthier lifestyles in a number of ways than never drinkers," he said, and these factors could also influence health. But the results did take into consideration differences in diet, smoking and education among participants, Kunzmann noted.

In general, most people agree that "if you drink alcohol, drinking less reduces your risk" of health problems, including cancer," said Dr. Timothy Naimi, an alcohol epidemiologist at Boston Medical Center who was not involved with the study. But there could be other factors that "may make light drinkers 'appear' to be better off statistically, because they are socially advantaged," he told Live Science.

The researchers said that they hope their study sparks conversation about reducing the recommended alcohol intake in countries' guidelines. The U.K. guidelines, for example, recommend that both men and women should have fewer than six drinks a week (less than one drink a day), whereas the U.S. guidelines state that men shouldn't have more than two drinks a day and women no more than one, according to Kunzmann.

However, public health guidelines take into account many more factors than the study authors did, Kunzmann said. And the team cautioned that nobody really knows why light drinking might have a benefit such as cardiovascular protection or even if the results are caused by unrelated factors such as being more health-conscious.

"We're not telling people what they can or can't do or what they can or can't drink," Kunzmann said. "We're just trying to give them reliable evidence so that they can make their own informed, healthy decisions."

Originally published on Live Science.

You've probably heard of the brain's reward network. It's activated by basic needs — including food, water and sex — and releases a surge of the feel-good neurotransmitter dopamine when those needs are met. But it can also be hijacked by drugs, which lead to a greater dopamine release than those basic needs.

But the reward network isn't the only brain network altered by drug use. A new review concluded that drug addiction affects six main brain networks: the reward, habit, salience, executive, memory and self-directed networks.

In 2016, a total of 20.1 million people ages 12 and older in the U.S. had a substance-use disorder, according to the National Survey on Drug Use and Health, an annual survey on drug use. And drug addiction, regardless of the substance used, had surprisingly similar effects on the addicted brain, said the new review, published yesterday (June 6) in the journal Neuron.

The review looked at more than 100 studies and review papers on drug addiction, all of which studied a type of brain scan called functional magnetic resonance imaging (fMRI).

More than half of the studies out there look at the effects of drug use on the reward network, said Anna Zilverstand, lead author of the new review and an assistant professor of psychiatry at the Icahn School of Medicine at Mount Sinai in New York City. [7 Ways Alcohol Affects Your Health]

"Because we showed that the effects are very distributed across the six different networks … [we can conclude that] an approach that only looks at one of these networks isn't really justified," Zilverstand told Live Science. "This [finding] will hopefully lead other researchers to look beyond the reward network."

For example, the memory network is pretty much ignored in research on substance-use disorders, Zilverstand said. This network allows humans to learn non-habit-based things, such as a new physics concept or a history lesson. Some research has suggested that in people with substance-use disorders, stress shifts the person's learning and memory away from the memory network to the habit network, which drives automatic behavior, such as seeking and taking drugs.

Another less-studied network is the self-directed network, which is involved in self-awareness and self-reflection, the review said. In people with addictions, this network has been associated with increasing craving.

Two other networks are involved in substance-use disorders: The executive network is normally responsible for goal-maintaining and execution, but drugs can alter this network as well, reducing a person's ability to inhibit their actions. The salience network picks up important cues in a person's environment and redirects the individual's attention to them. (In people with drug addiction, attention is redirected toward drugs, increasing craving and drug-seeking.)

Which comes first, the brain activity or the drug use?

"For me, the most surprising [finding] was how consistent the effects were across addictions," Zilverstand said. What's more, "the fact that the effects are quite independent of the specific drug use points to them being something general that might actually precede drug use rather than be a consequence of drug use."

Zilverstand said she hopes that more studies will look at whether some people have abnormal brain activity in these six networks naturally and if that activity just gets exacerbated if they begin drug use. It's important to know if some of these traits precede drug use; if that's the case, it might be possible to identify people who are prone to addiction and intervene before an addiction begins, she said.

Some research has pointed toward this possibility already. For example, studies have shown that some people have "difficulties … inhibiting impulsiveness before drug use," Zilverstand said. "Some of these impairments precede drug use, and they may become worse with more drug use, but they exist before the problem escalates."

The good news, however, is that activity in four of these networks — executive, reward, memory and salience — moves back toward "normal" once drug use ends. "We know that four of the networks (partially — not fully) recover but not yet what happens to the other two networks," Zilverstand said in an email.

Zilverstand added that she's particularly excited about an ongoing study called the Adolescent Brain Cognitive Development (ABCD) Study, which is tracking 10,000 children across the U.S. from around ages 9 or 10 to age 20 (the children are now around 13). Some of these individuals will inevitably become addicted to drugs, most likely marijuana or alcohol, Zilverstand said.

"We'll be able to see if the effects that we found [in the review] exist in youth who have not yet abused drugs," she said, and she predicted that researchers will be able to find a lot of the effects identified in the review in the six brain networks.

The authors noted that because some regions of the brain are very small — for example, the amygdala, which is found toward the center of the brain — the studies can't identify strong signals from those areas on brain scans. So, it's possible that drugs affect additional networks in the brain that are hidden because of the limitations of our technologies, Zilverstand said.

"We don't want to conclude that [those effects] don't exist," she said.

Originally published on Live Science.

Worldwide, alcohol and tobacco cause much more death, disability and addiction than illegal drugs, according to a new review.

The review analyzed data from 2015 on global drug use — both overall and in 21 different regions — using data from the World Health Organization, the United Nations Office on Drugs and Crime, and the Institute for Health Metrics and Evaluation, as well as other sources. The researchers examined both the prevalence of drug use as well as the "health burden," in the form of death and disability tied to drugs.

The researchers found that, worldwide, an estimated 18 percent of people reported "heavy" alcohol use in the last month (heavy use corresponds to more than 60 grams of alcohol, or about four standard drinks, on one occasion). In addition, 15 percent reported daily tobacco smoking, 3.8 percent reported marijuana use in the past year, 0.77 percent reported amphetamine use in the past year, 0.37 percent reported non-medical opioid use in the past year and 0.35 percent reported cocaine use in the past year.

Some of the highest levels of alcohol consumption were in Central, Eastern and Western Europe, where the per-capita consumption was 11 to 12 liters (about 3 gallons) of pure alcohol a year, compared with about 6 liters (1.5 gallons) a year per capita worldwide. These regions also had the highest levels of daily tobacco smoking, with around 21 to 24 percent of those populations reporting daily smoking, according to the review. [Here's How Much Alcohol Is OK to Drink in 19 Countries]

Regarding addiction, an estimated 63 million people worldwide were dependent on alcohol in 2015, with about 843 cases of  alcohol dependence per 100,000 people. For comparison, about 20 million people were dependent on marijuana (260 cases per 100,000 people) and 17 million were dependent on opioids (220 cases per 100,000 people) in 2015.

However, the rates of marijuana and opioid dependence were almost threefold higher in the United States and Canada (a region called "high-income North America" in the report) than in the rest of the world, with an estimated 749 cases of marijuana dependence and 650 cases of opioid dependence per 100,000 people.

Tobacco smoking was tied to the greatest rate of death. For every 100,000 deaths in 2015, 110 were tied to tobacco, while just 33 were related to alcohol and seven to illegal drug use.

The researchers also calculated how many years of life were lost by people who died from drug use, or who were living with disability from drug use (which together were called "disability-adjusted life years," or DALYs). They found that tobacco smoking cost the human population 171 million DALYs, compared with 85 million DALYs for alcohol and 28 million DALYs for illegal drug use.

"Alcohol use and tobacco smoking are far more prevalent than illicit substance use, globally and in most regions," the researchers wrote in the May 11 issue of the journal Addiction.

And tobacco smoking accounted for most of the health burden due to drugs, they said. Still, the health toll of illegal drugs may be underestimated because available data on these drugs is limited.

For example, some countries and regions (including Africa, the Caribbean, Latin America and Asia) have little or no data on substance use and its associated health burden, the researchers said.

"Better standardized and rigorous methods for data collection, collation and reporting are needed to assess more accurately" the disease burden from substance use worldwide," the researchers said.

Original article on Live Science.

Unlike chocolate chip cookies or tomato soup, the invention of bread can't be pinned down to a single person or people; instead, it evolved to its present state over the course of millennia.

Although the modern version of sliced bread is a fairly new invention (Wonder Bread began marketing the first sliced loaf of bread in 1930), bread itself is an ancient food with origins dating back more than 22,000 years.

In 2004, at an excavation site called Ohalo II, in what is modern-day Israel, scientists found 22,000-year-old barley grains caught in a grinding stone: the first evidence of humans processing wild cereal grains. But these early "bread" creations were probably more like "flat cakes of ground seeds and grains heated on a rock, or in the embers of a fire," than standard sandwich bread, Howard Miller, a food historian and professor at Lipscomb Universityin Nashville, Tennessee, told Live Science. [Why It Took So Long to Invent the Wheel]

Bread grains, the first plants to be domesticated, were first harvested in the wild by the Natufians. This Mesolithic group of hunter-gatherers lived in the Jordan River Valley region of the Middle East about 12,500 years ago.

"The Natufians are thought to be the first people to make the transition between survival purely on foods that you harvest from nature to becoming farmers who control all aspects of the food supply," William Rubel, a food historian and author of "Bread: A Global History" (Reaktion Books, 2011), told Live Science. "The Natufians had the infrastructure for grinding barley and then making it into bread."

The Natufians had the earliest known agricultural-based society and would process grains into a coarse flour, from which they made a "small, pita-like, unleavened loaf cooked directly on the coals of a fire," Miller said.

Over the next several thousand years, agriculture and the cultivation of grains spread across the Middle East and southwest Asia through trade contacts with other hunter-gatherer peoples in the Nile Valley, Mesopotamia and east of the Indus Valley.

"Bread was the evolutionary spark that led to the development of state and large political units," Rubel said. "Bread allowed for the accumulation of surplus, and so the villages got bigger until you had actual cities."

More than 5,000 years after the Natufians began making flatbread, three civilizations were rapidly growing and expanding during the Bronze Age: the Egyptians, the Mesopotamians (in what is modern-day Iraq) and the Harappans (in the Indus Valley, in what is modern-day Pakistan). All three civilizations, considered the largest in the ancient world, depended on bread.

"Bread was the majority of their calories," Rubel said. "Bread allowed for the building of surpluses and developing of [social] classes. You didn't have a class of full-time artisans until you had bread."

The first-known leavened bread made with semi-domesticated yeast dates back to around 1000 B.C. in Egypt, according to Miller. However, scholars debate the exact origin, as evidence suggests that Mesopotamians also produced yeast-risen bread, Rubel said.    

In fact, the invention of yeast-risen bread likely has boozy roots. Ancient Egyptians used barley and emmer wheat both to brew sour beer and to make sourdough bread, according to a 1994 study in the journal Egyptian Archeology. The ancient Egyptians could have made beer by baking "richly yeasted dough" into "beer loaves," then crumbling that bread and straining it with water, which would then ferment into beer, according to the book "Ancient Egyptian Materials and Technology" (Cambridge University Press, 2000).

"Beer is liquid bread," Miller said. "They have the same ingredients — water, grain, yeast — just in different proportions."

From the cradle of civilization's flatbreads to the packaged supermarket slices we know today, bread has evolved alongside society, ever since humans first crushed grains against a grinding stone thousands of years ago.

Original article on Live Science. 

Drinking alcohol may increase women's risk for premenstrual syndrome, or PMS, a new meta-analysis from researchers in Spain suggests.

However, the review found only an association between drinking alcohol and PMS and didn't prove that drinking causes PMS or makes symptoms worse, the researchers said.

PMS is a group of symptoms that start about one or two weeks before a woman's period, according to the National Institutes of Health. Symptoms can include mood swings, tender breasts, food cravings, fatigue, irritability and depression. It's estimated that 20 percent to 40 percent of U.S. women experience moderate PMS symptoms and 3 percent to 8 percent experience severe symptoms, according to the review.

Some studies have found that PMS symptoms tend to be more severe among women who drink alcohol, but it's unclear whether this is due to the alcohol itself or if some women drink to cope with PMS symptoms, the researchers said. [7 Ways Alcohol Affects Your Health]

The new meta-analysis, from researchers at the University of Santiago de Compostela in Spain, analyzed information from 19 previous studies in eight countries involving more than 47,000 participants in total.

The researchers found that drinking alcohol was linked with a 45 percent increase in the risk of PMS and that heavy drinking — or consuming more than one alcoholic drink a day — was linked with a 79 percent increase in the risk of PMS.

The relatively large number of studies included in the meta-analysis and the consistency of the results suggest that alcohol intake may increase the risk of PMS, the researchers said.

However, this link could still be due to reverse causation — that is, researchers may be finding an association because women with PMS are drinking to cope with symptoms, said Elizabeth Bertone-Johnson, a professor of epidemiology at the University of Massachusetts Amherst, who studies premenstrual syndrome.

"I think it's really premature to link alcohol to worsening of premenstrual syndrome symptoms … based on this study," said Bertone-Johnson, who wasn't involved in the new analysis.

Nearly all of the studies included in the meta-analysis were retrospective, meaning that the women included in the studies already had PMS when they were asked about their alcohol intake, Bertone-Johnson noted.

"That, unfortunately leaves the possibility that their menstrual symptoms themselves led them to drink alcohol," Bertone-Johnson told Live Science.

To better understand this link, more studies are needed that start tracking women in their teenage years and follow them over time to look at alcohol intake and the development of PMS, she said.

Still, if women want to cut down on alcohol and see if it improves their PMS symptoms, "that's very reasonable," Bertone-Johnson said. But, scientifically, it's unclear if reducing alcohol intake will improve PMS symptoms in the majority of women, she added.

The new study was published today (April 23) in the journal BMJ Open.

Original article on Live Science.

Beer connoisseurs would certainly give you an odd look if you imbibed your Guinness from a martini glass.

But one mathematician says this actually might be the best glass to serve Guinness in because it allows the beer's bubbles to settle faster.

William Lee, a professor of mathematics at the University of Huddersfield in England, has studied the unique flow of bubbles in the creamy stout, and recently weighed in on which type of glassware would hypothetically be best to serve the famous Irish beer in.

"People think that the Guinness glass is designed to optimize the settling time," Lee said in a statement. "But now we have a better understanding of the theory behind it, we might be able to make an even better glass so that it settles faster. Unfortunately, the ideal shape would look like a giant cocktail glass!"

In 2012, Lee and colleagues used computer simulations to explain exactly why the bubbles in Guinness and other stouts appear to sink downward while the beer is settling — seemingly defying the laws of physics. (After all, since the bubbles are less dense than the liquid, shouldn't they always rise?)

At that time, the researchers determined that the bubbles were indeed obeying the laws of physics — they were sinking because of a "circulatory flow," or the current in the glass. That is, the bubbles were still rising relative to the liquid, but sinking relative to the glass due to the circulating flow, which is directed downward at the sides of the glass, and upward in the middle, according to Lee. But what caused this circulating flow? [7 Ways Alcohol Affects Your Health]

Lee and colleagues found that it was the shape of the traditional pint glass — which is wider at the top than the bottom — that produced this circulation. Live Science previously reported that this glass shape allows more bubbles to rise from the middle of the glass than its sides. A higher density of bubbles in the middle of the glass versus the sides creates a "fountain" of upward flowing beer in the middle. And the imbalance in density ultimately results in the circulation — downward flowing bubbles at the sides, and upward flowing in the middle.

The cocktail glass, with its steeply slanted sides, would allow the bubbles to flow more quickly to the bottom and then rise to the top, according to the Daily Mail.

Lee's 2012 paper used computer simulations to show why bubbles flow downward; and now, Lee has confirmed these findings using a mathematical model, which increases the researcher's confidence in the results. A paper describing the model was published in the March issue of the American Journal of Physics.

Original article on Live Science.

U.S. drinking guidelines are too boozy, according to a new study.

The research, which analyzed data from nearly 600,000 people in 19 countries, found that drinking more than 100 grams of pure alcohol per week (the equivalent of about seven standard drinks in the United States) was linked to an increased risk of early death during the study period.

But many countries have drinking guidelines that consider 100 grams of alcohol a week to be well within the range of "safe" drinking. For example, U.S. guidelines recommend that men drink no more than 196 grams per week, or 14 standard drinks. (For women, U.S. guidelines fall within these recommended amounts, at no more than 98 grams a week.) In Canada, guidelines recommend no more than 136 grams per week for women, and no more than 204 grams per week for men.

In the new study, published yesterday (April 12) in the journal The Lancet, researchers concluded that drinking guidelines should be lowered to a limit of 100 grams a week.  [Here's How Much Alcohol Is OK to Drink in 19 Countries]

"This study has shown that drinking alcohol at levels which were believed to be safe is actually linked with lower life expectancy," as well as other health problems, study co-author Dr. Dan G. Blazer II, a professor emeritus of psychiatry at Duke University, said in a statement. The study's findings are in line with new recommendations for safe drinking in the United Kingdom, which recommend no more than six standard U.K. drinks a week for men and women.

Researchers have previously found that drinking guidelines vary widely around the world. For that reason, it's a little unclear exactly how much alcohol is "safe" to drink; in other words, it's hard to tell what level is associated with a low risk of health problems and substance disorders.

For the new study, the researchers analyzed information from 599,912 people in high-income countries who drank alcohol but did not have heart disease at the study's start. The median follow-up period was 7.5 years.

About half the people in the study reported drinking more than 100 grams of alcohol per week, and 8 percent drank more than 350 grams per week.

Drinking more than 100 grams of alcohol per week was linked with a lower life expectancy. For example, life expectancy was 6 months lower among those who drank 100 to 200 grams per week, and life expectancy was 1 to 2 years lower among those who drank 200 to 300 grams per week, compared with those who drank less than 100 grams a week. The highest level of drinking in the study — more than 350 grams per week — was linked with a 4- to 5-year reduction in life expectancy.

The study also found that alcohol consumption was linked with an increased risk of stroke or heart failure, as well as an increased risk of death from hypertensive disease (high blood pressure) or an aortic aneurysm. There was no clear threshold below which alcohol consumption stopped being associated with these conditions, the researchers said.

In contrast to those findings, alcohol consumption was also linked with a slightly lower risk of nonfatal heart attack. This slightly lower risk of heart attack tied to alcohol consumption must be balanced against the other "serious, and potentially fatal, cardiovascular diseases" linked with alcohol consumption, lead study author Dr. Angela Wood, a lecturer in biostatistics at the University of Cambridge in the United Kingdom, said in the statement.

Overall, the public health message of the study is "if you already drink alcohol, drinking less may help you live longer and lower your risk of several cardiovascular conditions," Wood said.

The researchers noted that the study tracked people's alcohol consumption for at least a year but did not examine the effect of alcohol consumption over a person's entire lifetime. They also noted that the study was not able to account for people who reduced their alcohol consumption due to health complications.

Original article on Live Science.

Here's a number that's hard to swallow: U.S. adults consume more than 17 billion alcoholic drinks during binges each year, according to a new report.

That works out to about 470 drinks per binge drinker per year, according to the report, from the Centers for Disease Control and Prevention (CDC).

But how did the CDC calculate these numbers?

The results are based on interviews with more than 400,000 U.S. adults in all 50 states in 2015. The interviews were carried out monthly in each state, and included a representative sample of adults.

Participants were asked how many times they binge drank in the last month, and how many drinks they consumed on these occasions. Binge drinking was defined as consuming four or more drinks per occasion for women, and five or more drinks per occasion for men. [7 Ways Alcohol Affects Your Health]

Then, the researchers took these monthly binge-drinking episodes and multiplied it by 12 to get a yearly estimate. Because the interviews took place during each month of the year, the researchers were able to take into account seasonal variation in drinking, they said.

The report found that about 17 percent of U.S. adults, or 37 million people, reported binge drinking in 2015. Each binge drinker reported an estimated 53 binge-drinking episodes per year, or about once a week, and consumed an average of seven drinks per episode.

The researchers then multiplied the estimated total number of binge-drinking episodes by the largest number of drinks consumed per episode for each drinker, for a whopping 17.5 billion binge drinks consumed in 2015.

Binge drinking can result in dangerous behavior, such as drunk driving; and over time, it can increase the risk of serious health problems such as cancer, heart disease and liver failure, according to the CDC.

"This study shows that binge drinkers are consuming a huge number of drinks per year, greatly increasing their chances of harming themselves and others," study co-author Dr. Robert Brewer, the lead researcher in the CDC's alcohol program, said in a statement. "The findings also show the importance of taking a comprehensive approach to prevent binge drinking, focusing on reducing both the number of times people binge drink and the amount they drink when they binge."

Editor's note: This article was updated on March 19 at 4:15 pm ET to include a more accurate description of how the researchers calculated the total number of binge drinks.

Originally published on Live Science.

Humans are still evolving… but before toasting to that, know this: Some of the genetic changes may make hangovers worse, a new study finds.

So far, only certain populations have genetic adaptations that make it hard for them to process alcohol, but there's no telling how fast it will spread to other populations, the researchers found.

As for people who already have the adaptation, they may have "reduced tolerance to alcohol in today's environment," study senior investigator Benjamin Voight, an associate professor of genetics at the University of Pennsylvania's Perelman School of Medicine, told Live Science in an email. [7 Ways Alcohol Affects Your Health]

The researchers did the study so they could learn which regions of the human genome have adapted — that is, evolved — over the past tens of thousands of years, Voight said. To investigate, they looked at publicly available data from the 1,000 Genomes Project, a large sequencing venture that's collected the genomes of more than 2,500 individuals of diverse ancestries — representing 26 different populations from four continents, Voight said.

After analyzing the genomes, the researchers found a few genetic sites that showed signs of adaptation.

One of these sites is known as the alcohol dehydrogenase (ADH) gene cluster. Previous research has also this pointed out, the study said.

Alcohol adaptations

When people drink alcohol, their bodies break it down into a toxic intermediary known as acetaldehyde. When acetaldehyde accumulates in the body, it can lead to adverse reactions, including facial flushing, nausea and rapid heartbeat, according to a 2007 report in the journal Alcohol Research Current Reviews.

But acetaldehyde typically doesn't stay in the body for long, because it gets metabolized into something less toxic known as acetate, which can be easily broken down and eliminated from the body.

Some people with East Asian ancestry have a genetic variation that makes it uncomfortable to drink too much alcohol. This variation reduces the function of the gene that converts acetaldehyde into the less toxic acetate, Voight said. This means that acetaldehyde can rapidly accumulate in these individuals, leading to hangover-worthy discomfort.

In other words, people with this genetic variation won't be able to drink too much alcohol without feeling its negative effects soon after. On the upside, people with this adaption might have a lower risk for alcohol dependence, the researchers wrote in the study.

However, not all humans are evolving these genetic changes. So far, it's just been detected in people with West African and East Asian ancestry, the researchers found.

It's not clear whether this adaption is happening to protect people against excessive drinking, Voight noted. Instead, the findings show that the pressures our ancestors experienced in the distant past have influenced the "make-up of our genome in many ways," he said. In turn, these adaptations have "influenced the diversity of traits and the susceptibility to disease that we observe today," Voight said.

Other adaptations

The alcohol-related adaptation wasn't the only finding from the study.

Another involves the glycophorin gene cluster, which is thought to play a role in how humans respond to germs, and in particular, with resistance to malaria. It's challenging to know how to interpret this finding, however. This adaptation could be a response to help humans build resistance against malaria, or it could be a response to another pathogen that was present in historical times, and also happens to fight malaria, Voight said.

The researchers also spotted a genetic sequence in the CT64 gene that early humans likely acquired when they had sex with Neanderthals. This sequence doesn't code for an obvious protein, but is expressed in the male testes, Voight said.

The study was published online Feb. 19 in the journal Nature Ecology and Evolution.

Original article on Live Science.

Recent headlines touted a link between daily alcohol consumption and a nearly 20-percent decrease in mortality risk — but those findings may be clouding the true relationship between alcohol and good health.

While a study of senior citizens did find a correlation between drinking two alcoholic beverages a day and increased longevity, the underlying reasons for this association aren't clear — and are likely not sufficient reason to celebrate booze as a health tonic, other research suggests.

The research in question is part of The 90+ Study, a massive, longitudinal study from the University of California, Irvine, that began in 1981 by surveying 14,000 senior citizens living in a retirement home. The initial participants answered questions about their health, hobbies and drinking habits involving alcohol, among other things. A 2007 paper published by the study's researchers found that seniors who drank two or more alcoholic drinks a day (it didn't matter what kind) had a 15-percent reduced risk of death compared to nondrinkers. [7 Ways Alcohol Affects Your Health]

"If in 1981 you were using alcohol, compared to people your same age who weren’t using alcohol, you lived longer," Dr. Claudia Kawas, a professor of neurology and neurobiology at the University of California, Irvine, and one of the co-principal investigators for The 90+ Study, said at an American Association for the Advancement of Science (AAAS) conference on Saturday (Feb. 17).

"I have no explanation for it," Dr. Kawas added, "but I do firmly believe that modest drinking is associated with longevity."

Kawas is not alone in her thinking — various other studies have linked moderate drinking to reduced risk of heart attack, stroke, and other conditions. Findings like these come with significant caveats, however — which Kawas quickly pointed out to the AAAS audience. "Keep in mind that I start studying people when they’re 90," Kawas said. "I think it’s very likely that individuals who have very excessive alcohol intake at younger ages don’t even make it to their 90s."

Alcohol's health impacts

Kawas' disclaimer echoes mounting research that suggests that the more alcohol a person drinks, the more likely that person is to experience adverse health effects.

According to the National Institute on Alcohol Abuse and Alcoholism, an estimated 88,000 Americans die from alcohol-related conditions every year, making it the third-greatest preventable cause of death in the United States after tobacco, poor diet and inactivity. Nearly 24,000 of these deaths were attributed to liver diseases, such as cirrhosis and liver cancer.

Additionally, drinking alcohol has been associated with an increased risk of contracting seven types of cancers, according to the American Society of Clinical Oncology, with greater alcohol intake generally being associated with greater cancer risk.

Binge drinking — defined as downing at least four drinks for women or five drinks for men within a few hours — is especially dangerous. One 2014 study found that adults in their 50s and 60s who reported binge drinking once a week were twice as likely to die over the following 20 years as were adults of the same age who drank less.

So, where do alcohol's apparent longevity benefits come from? According to a 2016 meta-analysis of 87 studies linking alcohol consumption and longevity, casual drinking may be an indicator of other lifestyle factors related to good health rather than a cause.

Older individuals who abstain from drinking might do so because of existing health issues, the study said, or because they had problems with excessive drinking in the past. In other words, if a person is still drinking at age 90, their health is likely good enough for them to do so. Good health among senior citizens can be attributed to a multitude of other lifestyle factors including diet, exercise and strong social relationships, The 90+ study reported.

Because it's so hard to tease out cause and effect in studies like these, it's too soon to say whether moderate drinking is indeed a health benefit, a risk or neither. The bottom line is: If you drink, drink moderately and because you enjoy it — not because you want to live forever.

Originally published on Live Science.

Alcohol may take a greater toll on the brain than marijuana does, especially for teens, a new study finds.

Specifically, researchers found that chronic alcohol use is linked to decreases in the brain's gray matter — which consists of brain cell bodies and synapses — in both teens and adults. In adults, alcohol use was also linked to declines in the integrity of the brain's white matter, which is made primarily of the long nerve fibers that zip messages through the nervous system. Cannabis use, on the other hand, was not associated with either gray- or white-matter declines.

"The difference between the alcohol and the cannabis is pretty dramatic," said lead study author Kent Hutchison, a professor of psychology and neuroscience at the University of Colorado Boulder. [7 Ways Marijuana May Affect the Brain]

The study was published in the December issue of the journal Addiction.

Marijuana and the brain

The research shouldn't be taken as the be-all and end-all in the great debate over whether cannabis is bad for the brain. For one thing, the study looked only at marijuana use in the past 30 days, and the participants had fairly low levels of pot consumption. In addition, Hutchison told Live Science, there could be subtle brain changes that the study's measurements could not capture.

But the study fits in with a body of work that has found mixed results regarding marijuana and the brain. Some animal research, for example, hints that at least some cannabinoids, the compounds in cannabis, may be protective for the neural system, Hutchison said. Studies in humans, on the other hand, have returned varied results, and many have been too small-scale to draw firm conclusions. One large study published in 2016 failed to find changes in gray matter after marijuana use but found that the drug was linked to declines in white-matter integrity, or the quality of connections between brain cells, especially for people who started using the drug at a young age.

Part of the problem is the challenge of untangling marijuana use from the use of other substances, especially alcohol, Hutchison said. Another problem is determining whether the drug actually causes the brain changes that are observed. One large study of twins published in 2015 found that brain differences between pot users and nonusers predated the marijuana use rather than being caused by it; pot smokers might have genetic or environmental factors that predispose them to cannabis use, the researchers concluded.

The new study had the advantage of a large sample size. The researchers looked at brain scans from about 850 substance-using adults ages 18 to 55 and about substance-using 440 teens ages 14 to 19, all of whom reported varying levels of alcohol and cannabis use. Alcohol was more common than pot as a substance of choice, with 487 adults (57 percent) and 113 teens (26 percent) reporting that they'd used only alcohol in the past six months, and 5 adults (0.6 percent) and 35 teens (8 percent) saying they'd used only cannabis in the past six months. Others used both.

Alcohol versus pot

Hutchison and his team were able to statistically control for the use of alcohol while looking for the effects of cannabis, and vice versa. What they found for alcohol use was not surprising, considering booze is a known neurotoxin, Hutchison said: Heavier alcohol use led to greater declines in gray matter and declines in the quality of connections in white matter. [7 Ways Alcohol Affects Your Health]

In contrast, "we don't see any statistically significant effects of cannabis on gray matter or white matter," Hutchison said.

The findings have public health implications, he said. There are limited funds in the public coffer for minimizing the damage of people's recreational substance use, so focusing on the substance that does the most damage might make sense, Hutchison said. But there are also many more research questions to answer, and future studies could look at the long-term impacts of cannabis use by following the same people over time, the researchers wrote.

There is also a need for more research into the interaction between alcohol and cannabis, Hutchison said, especially because people who use these substances tend to use both.

Originally published on Live Science.

There may be a mean drunk inside every man — and now scientists think they might know why.

According to a new paper published in the February issue of the journal Cognitive, Affective & Behavioral Neuroscience, MRI scans of drunk and sober men show that alcohol-related changes in the prefrontal cortex — the region of the brain thought to be responsible for moderating social behavior and aggression, among other executive functions — may be responsible for booze-induced anger.

In the new study, researchers from the University of New South Wales in Australia recruited 50 healthy men (ages 18 to 30 years old) to play a standard aggression-inducing game while lying in an MRI scanner. While alcohol had been previously shown to disrupt the normal functioning of multiple brain regions (including parts responsible for working memory, hand-eye coordination and sleep quality), MRI evidence linking aggression to alcohol-induced changes in the prefrontal cortex had been lacking until now, the researchers said. [7 Ways Alcohol Affects Your Health]

Volunteers were asked to guzzle either two alcoholic drinks or two nonalcoholic placebo drinks before attempting the aggression game. Each member of the intoxicated set drank two cups of lemony vodka tonic, mixed to raise each drinker's breath alcohol concentration above the legal driving limit in Australia, 0.05 percent.

After downing their drinks, the participants entered the MRI scanner to play a few dozen rounds of the aggression game, which was described to them as a competitive reaction-time task. Each participant was shown a screen and had to race his "opponent" (which was actually a computer AI, but was described to the participants as a real student playing the game remotely from an adjacent room) to press a button whenever he saw a colored square appear on-screen.

If the participant hit the button faster than his opponent, the opponent was punished with a preselected blast of noise ranging in intensity on a scale of 1 to 4. Likewise, if the AI opponent was faster, the human player was punished with an annoying blast of noise. Even if the human player won a round, he was shown the level of noise intensity that his opponent had selected for him, allowing the human player to learn how aggressive each opponent was.

The MRI scans showed that intoxicated players showed a significant dip in brain activity in their prefrontal cortices, compared with sober players, when making an aggressive response. Specifically, the booze drinkers showed lower activity in regions known as the dorsomedial and dorsolateral prefrontal cortices, which are related to working memory and inhibition.

"Aggression is thought to occur because alcohol focuses attention on instigatory cues (such as the noise blasts) and away from inhibitory cues (norms proscribing aggression)," the researchers said in the study.

In other words, the researchers believe that alcohol's dampening effects on the prefrontal cortex could make intoxicated players more biased toward hostile cues and less wary of social etiquette, resulting in more aggressive behavior. The reduction in activity in these regions "may reflect reduced self-awareness" in intoxicated people, they added.

While further MRI studies with larger samples of drunk and sober participants are needed, this study gives researchers a clearer picture of where alcohol-induced aggression may come from.

If nothing else, it provides weary bartenders with a more specific refrain to yell at over-the-limit patrons: "Hey, buddy, I think your dorsomedial prefrontal cortex has had enough!"

Originally published on Live Science.

Just in time for that after-work cold one, a bevy of headlines are promising that a little bit of booze won't kill you; in fact, it might "cleanse" your brain and reduce your risk of dementia.

So, what's the science behind this eyebrow-raising claim? Well, it's not necessarily as out-there as it sounds, but don't go on a liquor binge just yet. The research was done on mice, which metabolize alcohol differently than humans, and it shouldn't be taken as prescriptive, wrote the authors Friday (Feb. 2) in the journal Scientific Reports.

"Naturally, this study performed in mice should not be viewed as a recommendation for alcohol consumption guidelines in humans," wrote senior study author Maiken Nedergaard and her colleagues in the paper. Nedergaard is a neuroscientist at the University of Copenhagen's Center of Basic and Translational Neuroscience. [7 Ways Alcohol Affects Your Health]

Brain flush

Nedergaard and her colleagues discovered in 2012 that the cerebral spinal fluid (CSF) that surrounds the brain and spinal cord isn't just a cushion against shocks. It also actively flushes away waste products, including the protein amyloid β, which is frequently found in abnormal clumps in the brains of people with Alzheimer's. The researchers dubbed this cerebral garbage disposal the "glymphatic system."

Meanwhile, research on alcohol and the brain has shown clearly that chronic, heavy drinking is a very dangerous activity. According to the Centers for Disease Control and Prevention (CDC), long-term heavy alcohol use has been linked to conditions ranging from cancer to heart disease to dementia.

But as any connoisseur of health news can attest, there are also multiple studies finding that small amounts of alcohol — say, a 5-ounce glass of wine a day — might be linked to a lower risk of many of those same conditions, including dementia, cardiovascular disease and many cancers. (Though even low amounts of alcohol consumption are linked to some cancers, especially breast cancer, a 2009 study published in the Journal of the National Cancer Institute found.)

Alcohol and the brain

To investigate that seeming paradox, Nedergaard and her colleagues studied the effect of alcohol on the glymphatic systems of mice. They dosed the animals with either low, medium or high levels of alcohol. The low dose was the equivalent of 2.6 drinks of alcohol for a 154-lb. (70 kilograms) person, with a drink defined as 5 ounces of wine with 12 percent alcohol, or 12 ounces of 5-percent-alcohol beer. The medium dose was the equivalent of 7.9 drinks for a 154-lb. person, and the high dose was 21 drinks. However, these body weight comparisons aren't quite accurate because they don't take into account that mouse metabolisms are faster than humans', Nedergaard told Newsweek.

Although the findings don't easily translate to people, they do provide a potential explanation for why alcohol seems damaging in large quantities but potentially helpful in small doses. Using fluorescent substances injected into the mice's cerebral spinal fluid (the stuff found to wash away garbage), the researchers traced the CSF through the brain. They found that immediately after a single low dose of alcohol, the CSF flow increased by 40 percent. Medium and high doses, by contrast, decreased the flow of the CSF by around 30 percent. The decrease may occur because higher levels of alcohol temporarily lower the amount of blood the heart moves with each pump, and blood flow helps drive the CSF flow, the researchers wrote. [Inside the Brain: A Photo Journey Through Time]

To test the effects of chronic alcohol consumption, the researchers gave the mice low or medium doses of alcohol for 30 days straight. (They skipped the high doses, because those levels killed 40 percent of the mice in pilot studies.)

Twenty-four hours after the last dose of alcohol, mice that had been given low doses of alcohol showed 19 percent improvements in glymphatic function, or how well the CSF was flushing out waste, over mice that had been given plain saline as a control. Mice given medium doses saw their glymphatic function return to normal, but did not get any health boost.

In behavioral tests, mice given chronic low doses of alcohol were just as likely to explore new objects as mice given saline, the researchers found. However, mice given medium doses were less interested. Those findings suggested that low amounts of alcohol didn't damage learning and memory, but medium doses did. Mice given low doses of alcohol also showed less inflammation in their brains than mice not exposed to alcohol at all.

Drinking choices

These brain processes could explain why alcohol seems to protect against dementia in small amounts, because it appears to improve the brain's self-cleaning system, the researchers wrote.

In that sense, the findings provide new avenues for research that could help illuminate why alcohol has the health effects it does. But one animal study isn't enough to alter human health recommendations — which already give the OK to a little bit of booze each day. According to the Department of Health and Human Services (HHS) and the U.S. Department of Agriculture (UDSA) Dietary Guidelines for Americans, up to one drink a day for women and two drinks a day for men can be part of a healthy diet.

However, the guidelines warn, many mixed drinks and beer varieties contain more alcohol than the standard used in public health research, so the amount of actual beverage allowed each day may be disappointingly small.

Original article on Live Science. 

A word of caution to tea lovers: Let your cuppa cool a bit before taking a sip. A new study from China finds that drinking tea at extremely high temperatures may increase a person's risk of esophageal cancer, especially if that person also consumes too much alcohol and is a smoker.

Researchers found that people in China who consumed scalding tea — and also smoked tobacco and drank excessive amounts of alcohol — had a five times greater risk of esophageal cancer than people who had none of these three habits, according to the findings. [10 Do's and Don'ts to Reduce Your Risk of Cancer]

China has one of the highest rates of esophageal cancer in the world, according to the study, publishedtoday (Feb. 5) in the journal Annals of Internal Medicine.

In particular, the researchers found that drinking very hot tea, along with smoking and drinking alcohol, was linked to an increased risk of squamous cell carcinoma of the esophagus. Squamous cells line the esophagus, and this type of cancer is the most common form of esophageal cancer in the U.S., according to the American Cancer Society (ACS).

But how might hot tea raise a person's risk of esophageal cancer? Although the exact mechanism is not known, research has suggested that frequently consuming scalding liquids may result in long-term injury to the cells lining the esophagus, said lead study author Dr. Jun Lv, an epidemiologist at Peking University Health Science Center in Beijing. Indeed, frequently drinking very hot liquids, prepared at temperatures of 149 degrees Fahrenheit (65 degrees Celsius) — which is much hotter than a typical cup of coffee or tea — can increase the risk of squamous cell carcinoma of the esophagus, according to the ACS.

These heat-related changes to the esophageal lining may also increase the likelihood of damage from other risk factors for esophageal cancer, such as smoking and heavy drinking, which may damage the DNA in cells that line the esophagus, Lv told Live Science.

Tea drinkers in China

In the study, researchers looked at data from about 456,000 people in China ages 30 to 79. At the beginning of the study, the people completed a lifestyle questionnaire that asked how frequently they consumed tea, how much they consumed, how they prepared the beverage and which type of tea they drank. The participants were also asked whether the usual temperature of their tea was room temperature or warm, hot or burning hot. [4 Awesome Perks of Drinking Tea]

Though the researchers found a fivefold increased risk of esophageal cancer for people who drank scalding tea, drank large amounts of alcohol and smoked tobacco compared with people who didn't do these things, not all tea drinkers need to avoid a steaming-hot cup, according to the study. The new study found that daily hot-tea consumption — even if it was served burning hot — was not associated with an increased risk of esophageal cancer in people who were not smokers and did not drink alcohol heavily, Lv said.

But for people who drink too much alcohol or smoke tobacco, avoiding very hot tea might be beneficial for preventing esophageal cancer, Lv said.

Lv noted that the findings might apply to people in countries other than China as long as these individuals had lifestyle habits that included smoking and drinking alcohol excessively, as well as consuming scalding beverages and foods. But the most important ways to prevent esophageal cancer are to avoid tobacco and excessive alcohol use, she added.

One limitation of the study is that it relied on self-reported information from participants about their hot beverages and not on actual measurements of tea temperatures, the researchers wrote. It's also possible that consuming other types of scalding beverages and foods may have contributed to the results observed, the researchers said. In other words, tea might not have been the only hot culprit.

However, the findings should not cause tea lovers to give up the hot beverage, which has many health benefits. Most people in the U.S. typically drink their tea — and coffee — at a temperature that seems unlikely to cause esophageal cancer, according to an editorial by two cancer researchers that was published alongside the study in the same journal.

But for fans of piping-hot beverages, it may be a good idea "to wait for the liquid to cool a bit first," the editorial suggests.

Originally published on Live Science.

Scientists have cracked a frothy mystery: the physics of fizz.

Many people know that frothy drinks get their pop and sparkle from tiny bubbles of carbon dioxide bursting out of their liquid mix. They might also know from experience that the harsh skittering of seltzer across a tongue feels different from the smooth foam of Champagne, the sweet effervescence of a cola, or the pizzazz of club soda. But until recently, scientists didn't know how differently carbon dioxide behaves in various drinks, or why.

A paper published Jan. 9 in The Journal of Physical Chemistry B offers the most complete answer yet to that question. A team of chemists from China's Jilin University and the University of Minnesota built complex models of carbonated cola (essentially, sugar and water), Champagne (alcohol and water) and club soda (salt and water) and studied them to figure out how these solutions change the behavior of dissolved carbon dioxide. They also built a model of pure carbonated water (seltzer), a substance whose physics are already well understood, to check that their models worked properly. [Raise Your Glass: 10 Intoxicating Beer Facts]

They found that for all three of the drinks they studied, carbon dioxide popped and fizzed out of the solution more slowly and less intensely than in pure seltzer water — but for different reasons.

In a carbonated drink, tiny clumps of CO2 are dissolved in the water, just like the sugar in a cola, according to the paper. But those clumps of CO2 don't dissolve very well, and as soon as the drink is exposed to open air, they start to burst out of the solution as bubbles, rise to the surface and disappear into the atmosphere.

That process doesn't happen all at once, the researchers found. This is because water is viscous — its H2O molecules cling to one another with charged bonds between their little Mickey-Mouse-ear hydrogen atoms and big oxygen atoms — so the CO2 must make its way through that lattice in order to escape.

Bizarrely, both the alcohol in Champagne and the sugar in the cola actually reduce the total number of hydrogen bonds between the water molecules, thus cutting the number of bonds holding the CO2 in place. And yet both still release CO2 more slowly than pure water. (The salt in club soda increases the number of hydrogen bonds, so it makes sense that it holds to CO2 more tightly.)

So why do Champagne and cola hold to CO2 about as tightly as club soda, despite having fewer hydrogen bonds?

The researchers showed that sugar and alcohol actually change the entire shape of the water around them. Even as the hydrogen bonds to water molecules, preventing them from bonding to one another, they cause those molecules to squeeze closer to one another — crushing in more densely around all that dissolved CO2, and holding it in place effectively even without hydrogen bonds, the researchers explained.

This kind of modeling is important, the researchers wrote, because it helps answer basic questions about the physics, and flavor, of carbonated beverages in ways that are very difficult to accomplish with direct experiments. Because CO2 dissolves so quickly and readily in all of these drinks, from Champagne to seltzer, measurements of the variations between them are difficult to make, but they make a big difference in the drinks' flavors.

Originally published on Live Science.

The ancient Greeks may have liberally indulged in wine, but that's not the only alcoholic beverage they imbibed, according to a new study that describes the discovery of two potential Bronze Age breweries.

The "stout" discoveries mark what may be the oldest beer-making facilities in Greece and upend the notion that the region's ancient go-to drink was only wine, the researchers said.

"It is an unexpected find for Greece, because until now all evidence pointed to wine," study researcher Tania Valamoti, an associate professor of archaeology at Aristotle University of Thessaloniki, in Greece, told Live Science. [Raise Your Glass: 10 Intoxicating Beer Facts]

The finding hints that prehistoric Greeks were "using alcoholic drinks for feasts all year-round, instead of just on a seasonal basis," when grapes were ripe, Brian Hayden, a professor of archaeology at Simon Fraser University, in British Columbia, Canada, who wasn't involved with the study, told Live Science.

Beer time

Archaeologists found the remains of several buildings that may have been used for beer making: some at Archondiko in northern Greece, and another at Agrissa, a site south of Archondiko on the eastern side of Greece. Both sites had been wrecked by fire, which turned them into time capsules of sorts, Valamoti said. After the fire, the prehistoric people appear to have moved out, leaving countless burned artifacts behind, including the remains of sprouted cereal grains.

At Archondiko, archaeologists found about 100 individual sprouted cereal grains dating to the early Bronze Age, from about 2100 to 2000 B.C. At Agrissa, they found about 3,500 sprouted cereal grains dating to the middle Bronze Age, from about 2100 to 1700 B.C.

The discovery of sprouted cereal grains is significant: To make beer, a brewer sprouts cereal grains (a process known as malting), which changes the grain's starch into sugars. This sprouting process is then interrupted by roasting the grain. Next, the grains are coarsely ground and mixed with lukewarm water to make wort, which helps convert the remaining starches into sugars. Finally, during alcoholic fermentation, "the sugars in the malt are used by yeast, which is present in the air or introduced with grapes or from other sources," Valamoti wrote in the study.

"I'm 95 percent sure that they were making some form of beer," Valamoti said. "Not the beer we know today, but some form of beer."

In addition, archaeologists found a two-chambered structure at Archondiko that "seems to have been carefully constructed to maintain low temperatures in the rear chamber, possibly even below 100 degrees Celsius [212 degrees Fahrenheit]," Valamoti wrote in the study. Given that a temperature of 158 degrees F (70 degrees C) is ideal for preparing the mash and wort, it's possible that ancient people used this structure during the beer-making process, she said. [The 7 Most Mysterious Archaeological Discoveries]

There were even special cups — 30 at Archondiko and 45 in the Agrisso house — near the sprouted grains, suggesting they may have been used to serve beer. However, the Archondiko cups were difficult to drink from, so it's possible that thirsty people there sipped beer through straws, Valamoti said.

She noted that although the discovery may be the oldest-known evidence of beer in Greece, it's not the oldest in the world, and beer isn't even the oldest alcohol on record. Prehistoric people appear to have discovered wine first, as there is evidence of wine residue on pottery from about 6000 B.C. in Georgia, Live Science previously reported, as well as from the sixth millennium B.C. in Iran and the fifth millennium B.C. in Armenia and Greece, Valamoti said.

As for beer, Egyptian records show that people drank it as early as the mid-fourth millennium B.C., and people in the Near East slurped down the amber liquid as early as 3200 B.C., according to the study.

"Textual evidence from historic periods in Greece clearly shows that beer was considered an alcoholic drink of foreign people, and barley wine a drink consumed by the Egyptians, Thracians, Phrygians and Armenians, in most cases drunk with the aid of a straw," Valamoti wrote in the study.

The finding, which was funded in part by the European Research Council project "PlantCult," was published online Dec. 30, 2017, in the journal Vegetation History and Archaeobotany.

Original article on Live Science.

Scientists think they know how alcohol damages DNA and increases the risk of cancer.

Researchers in England conducted the study in mice, however, experts say that the mechanisms linking alcohol to DNA damage are the same in mice and men. Indeed, earlier studies have shown strong links between alcohol and certain cancers in humans; in addition, the International Agency for Cancer Research classifies alcohol consumption as "carcinogenic to humans."

What wasn't clear, however, was how alcohol did its damage. [7 Ways Alcohol Affects Your Health]

The study, which was published Jan. 3 in the journal Nature, took a precise look at how exposure to alcohol, and the compounds that result when the body breaks down alcohol, cause damage to chromosomes in blood stem cells. These stem cells are crucial for replenishing cells lost throughout the life span, but once they are damaged, they can spread the damage further. (Stem cells can divide and replenish cells for long periods of time.)

In the study, the researchers gave mice doses of alcohol that would be equivalent to an adult human drinking one bottle of whiskey in a short period of time. Some of the mice were genetically engineered to remove two crucial mechanisms that protect against the harmful side effects of alcohol metabolism, leaving the mice vulnerable.

"When the body processes alcohol, it converts it into a highly reactive toxin called acetaldehyde, which damages DNA," said lead study author Dr. KJ Patel, a tenured principal investigator at MRC Laboratory of Molecular Biology in Cambridge, England.

Patel's previous work has shown that there are two mechanisms that protect the cells from acetaldehyde. "The first is an enzyme that detoxifies and removes the acetaldehyde," Patel said. The second mechanism springs into action after the damage is done and is comprised of "DNA repair systems that fix the damage when it occurs," he said.

Animal experiments

The researchers worked with three groups of mice: mice with both protection mechanisms in place; mice that didn't have the acetaldehyde-removing enzyme, called aldehyde dehydrogenase 2, but did have the DNA repair mechanisms; and mice with neither the enzyme nor the DNA repair mechanisms.

"If we remove just the first level of protection, which is just the enzyme that detoxifies [the acetaldehyde], just giving [the mice] one big dose of alcohol is enough to initiate four times more DNA damage than in normal mice," Patel said. "That level of damage is not very dissimilar to having spent a short period of time in front of Fukushima."

Though these mice were genetically engineered to lack this type of protection against acetaldehyde, many people either lack this protective enzyme or have an impaired function of it, according to Patel. This condition is especially common in Asia, where it affects about 5 million people, Patel estimated.

In addition, problems with the second layer of protection — the DNA repair mechanisms — are also fairly common.

These DNA repair mechanisms are "deficient in women who carry either the BRCA 1 or BRCA 2 mutation, which predisposes women to breast cancer," Patel said. Problems with DNA repair also occur in children with the disease called Fanconi's anemia, he added.

Stem-cell damage

In the study, the scientists focused on DNA damage in blood stem cells. Previous research has shown that alcohol affects blood cells, as many people with alcoholism become anemic, meaning they have too few red blood cells, Patel said.

This finding is significant: Malcolm Alison, a professor of stem-cell biologyat Queen Mary University in London,who was not involved in the study, said it is believed that most cancers arise from stem cells.

"Most of our organs and tissues have stem cells, immortal cells that replenish cells lost through the likes of old age throughout our lives, and the hematopoietic system is no exception," Alison said in a statement. (The hematopoietic system is how blood cells are generated in the body.)

"This new study from Cambridge now finds that mouse hematopoietic stem cells can be mutated by a metabolite of alcohol, acetaldehyde," Alison said.

This is not the first study that has linked alcohol to cancer. Alcohol is believed to be a contributing factor to at least seven types of cancer, including cancers of the blood, breast, mouth and neck, and digestive tract, Patel said.

Patel added that he is skeptical of claims about the positive effects of low doses of alcohol on human health.

"These claims are based on epidemiological studies on population groups," Patel said. "In many of these studies, there are other concerning variables."

The current research, however, did not focus on that question.

Originally published on Live Science.

Tips for Holiday Celebrating

For most people who don't have the lucky hangover-resistant genes, drinking at parties and celebrations comes with an inevitable hangover the next day.

But the pounding headaches and upset stomachs don't always have to be the aftermath of an alcohol-filled New Year's Eve outing. Here are seven wise tricks to ward off a brutal hangover. (Of course, the best way to avoid a hangover is to not down too much booze the night before.)

1. Clear drinks

Light-colored drinks, such as gin and vodka, cause a milder hangover than darker drinks, such as bourbon or whiskey, according to research. The reason appears to be what are called congeners, or toxic substances produced during alcohol fermentation. Clear drinks that are distilled many times contain lower concentrations of these congeners. [11 Surprising Facts About Hangovers]

2. No bubbles

Those bubbles in your beer and champagne can contribute to a hangover's severity, by increasing alcohol levels in the blood. The gas in carbonated beverages relaxes the sphincter between the stomach and the small intestine. The alcohol then can get into the intestines faster, where it is absorbed into the bloodstream.

3. Choice of mixer

Mixing liquor with a diet soda may sound healthier than drinking it straight up or with a full-calorie beverage, but it may also increase intoxication.

In one study detailed in the journal Alcoholism: Clinical and Experimental Research, in April 2013, people who had taken their vodka with diet sodas had higher blood alcohol levels than people who had downed an equal amount of vodka mixed with regular soda. The reason may be that the sugar in regular sodas keeps the stomach busy, and the alcohol doesn't reach the small intestine as quickly, the researchers suggested.

4. Have a drink … of water

Water is the silver bullet to hangovers. One of the main contributing factors to hangovers is dehydration. Alcohol suppresses the hormone vasopressin, which regulates the water levels in the body and causes the body to lose more water in the urine.

To counteract these effects of alcohol, doctors suggest following each alcoholic beverage with a glass of water.

5. Eat protein-rich snacks

Drinking on an empty stomach is a recipe for the worst hangovers. Anything that fills the stomach and keeps it busy during drinking can help prevent a severe hangover, but the best choice may be protein-rich snacks. Meat, nuts and cheese take longer to digest than most other foods.

6. Smoking makes it worse

The nicotine in tobacco and e-cigarettes might bring a brutal hangover by making people drink more. Some studies have suggested the two compounds boost the pleasurable effects of each other, which results in more smoking, and, in turn, more drinking.

Conversely, other studies have found that nicotine dampens the effect of alcohol, forcing people to drink more to get the buzz they are looking for.

Whichever is the case, anecdotal evidence strongly supports the idea that nicotine and alcohol go hand-in-hand, and that smoking when drinking simply means more drinking.

7. Hair of the dog?

One common hangover cure is to have more of what made a person sick in the first place. But a 2017 study in the Danish journal Ugeskriftet Laeger (or Weekly for Doctors) found that people who drink five beers when hungover experienced a decrease in blood pressure, heart rate and self-reported heart palpitations. However, the overall sense of well being didn't improve.

8. Ancient remedy

A placebo-controlled study conducted in Korea in September, 2017 found that an extract from the fruit of the oriental raisin tree, or Hovenia dulcis, didn't reduce overall hangover symptoms, but did seem to cause hangover symptoms to dissipate more quickly. The study also found reduced levels of inflammatory markers in the blood of people who took the extract, which could explain the quicker reduction in symptoms.

9. Multiple lines of attack

A review published in May 2017 found six products, from red ginseng to Korean pear juice, were effective at reducing some, but not all, hangover symptoms. The products and treatments were best at curbing nausea and vomiting and reducing feelings of tiredness, the review found. And none of the products completely wiped away all symptoms of hangover.

10. Dance it away

p> Using the alcohol-induced extra energy to hit the dance floor may keep you from drinking shot after shot. It also enhances the body's overall metabolic rate, which can clear alcohol out of the bloodstream faster, helping to prevent a severe hangover.

What's more, dancing is fun. The occasion, after all, is one to celebrate.

Original article on Live Science.

This holiday season, will you view the glass as half full or half empty? Well, that might depend on the size of the glass. A new study from England finds that over the past three centuries, wineglasses in England have ballooned in size, from holding the equivalent of a double shot of liquor to holding nearly two cups of liquid.

In the study, researchers at the University of Cambridge looked at the size of glassware over 300 years to see if there were any links between glass size and alcohol consumption. The findings were — one might  say — glass-shattering: From 1700 to 2017, the size of wineglasses increased almost sevenfold. More recently, wine consumption also went up, with intake quadrupling between 1960 and 1980 and then doubling between 1980 and 2004.

The study was published yesterday (Dec. 13) in the Christmas issue of the journal The BMJ, which is a tongue-in-cheek edition of the medical journal, which normally publishes serious research. [Here's How Much Alcohol Is OK to Drink in 19 Different Countries]

But how do you measure the average size of a wineglass in 1700? To do so, the researchers looked everywhere, including the archaeology department at the University of Oxford, the designs of the Royal Household, and various department stores and catalogs. They even checked eBay. In some cases, the sizes of the glasses were listed, but for the rarer and older models, they had to manually fill the antiques with water to measure how much they held.

After measuring more than 400 wineglasses spanning three centuries in England, the researchers found that in 1700, the typical wineglass held, on average, 2.2 fluid ounces (66 milliliters) of liquid. That's roughly the equivalent of a double shot of liquor. By 2017, however, wineglasses ballooned to hold, on average, 15.2 fluid ounces (449 milliliters) of liquid — nearly 2 cups — if you were to fill the glass to the very top.

At first, the reasons for the increase in size were technical. Certain advances — including the invention of lead crystal glassware (which is less fragile), automated manufacturing and the abolishment of the glass tax in the U.K. — made it cheaper to produce larger wineglasses.

But ultimately, the biggest factors in the growing size of the wineglasses may be cultural, according to senior study author Dame Theresa Marteau, a psychologist and the director of the Behaviour and Health Research Unit at the University of Cambridge. Most likely, because of changes in the "affordability, availability and marketing" of wine, people and industries began to want and use larger glases.

Americans may also be to blame (or thank) for the increase in size in England's wineglasses: British manufacturers cite demands for supersize glasses by the U.S. market in the 1990s.

But does a larger glass really cause you to drink more? Though the researchers noted that the study does not prove cause and effect, a larger container size for other food products has been associated with increased consumption, and previous research has linked alcohol consumption and cup size.

The reason for this isn't simply that people pour more wine with a larger glass, Marteau told Live Science. Instead, perception may play a role — you believe you're drinking less with a larger glass — as well as enjoyment, as larger glasses can potentially release more of the wine's aroma.

Marteau added that the study caused her to notice the increase in size of her own glassware over the past several decades and, as such, shift back to the smaller sizes.

Originally published on Live Science.

The holidays are full of tasty treats and festive cocktails — but instead of Christmas cheer, some alcoholic beverages may cause other, less pleasant feelings, a new study from England suggests.

In the study, researchers examined how consuming different types of alcohol, such as beer, spirits and wine, could affect a person's emotions when drinking at home or out in public. Their findings suggest that spirits, which have higher alcohol concentrations, are frequently associated with feelings of aggression.

“Understanding emotions associated with alcohol consumption is imperative to addressing alcohol misuse, providing insight into what emotions influence drink choice between different groups in the population,” the researchers wrote in the study. [7 Ways Alcohol Affects Your Health]

For the study, the researchers used data from the Global Drug Survey, which is the world’s largest online survey of legal and illicit drug and alcohol use among adults. The survey includes questions on alcohol consumption and the feelings associated with drinking beer, spirits and red or white wine when at home or out. The emotions analyzed in the survey included energized, relaxed, sexy, confident, tired, aggressive, ill, restless and tearful.

Specifically, the researchers looked at responses from roughly 30,000 survey participants between ages 18 and 31. The participants were from 21 countries and had drunk each of the specified types of alcohol within the past year, according to the study.

The results showed that different types of alcohol can trigger different emotions. Spirits, for example, were more likely to elicit negative feelings than all the other types of alcohol, the researchers said.

But red wine was linked to more positive feelings: About 53 percent of the survey participants said they felt relaxed after drinking red wine. Roughly 50 percent of the participants also associated this feeling with drinking beer. Spirits, however, were the least likely to be associated with relaxation, according to the study.

"For centuries, the history of rum, gin, vodka and other spirits has been laced with violence," study co-author Mark Bellis, a professor of public health at Bangor University in the U.K., said in a statement. "This global study suggests even today consuming spirits is more likely to result in feelings of aggression than other drinks."

But aggression wasn't the only emotion associated with sipping spirts. The researchers also found that spirits were associated with more positive emotions than beer or wine, including feelings of energy, confidence and sexiness.  

The researchers found that survey responses largely differed based on level of education, country of origin and age. For example, participants between ages 18 and 24 were more "likely to associate any type of alcohol with feelings of confidence, energy and sexiness when drinking away from home," the researchers said.

Gender and level of alcohol-dependency also seemed to have an effect on participants' emotions. Compared with men, women were more like to associate their feelings with different types of alcohol.

The one exception, however, was aggression. Men were "significantly more likely to associate feelings of aggression with all types of alcohol, as were those categorized as heavy/dependent drinkers, who were six times more likely to do so than low risk drinkers," the researchers said. (A questionnaire was used to assess a person's level of alcohol dependency.)   

Also, dependent drinkers were five times more likely to say they felt energized from alcohol than "low-risk" drinkers, suggesting that dependent drinkers rely on alcohol to generate the positive emotions they associate with alcohol, the researchers added. ("Low-risk" drinkers refers to drinkers who were less-dependent on alcohol.)

Although the study doesn't provide explicit evidence linking certain emotions to different types of alcohol — in other words, it doesn't prove that a specific type of alcohol causes a specific emotion — it demonstrates the effect that drinking beer, wine or spirits can have on a person's feelings. The researchers also noted that several other factors could influence feelings elicited by alcohol, such as advertising, when and where alcohol is drunk, and the alcohol content of different drinks.

The findings were published today (Nov. 21) in the journal BMJ Open.

Originally published on Live Science.

This remarkable find deserves a toast: People were fermenting grapes into wine about 8,000 years ago in what is now the Republic of Georgia, say scientists who found what's now considered the oldest known winemaking site on record.

Archaeologists found ceramic jars that showed evidence of winemaking during an excavation of two Neolithic sites called Gadachrili Gora and Shulaveris Gora, which are in the South Caucasus, about 30 miles (50 kilometers) south of Tbilisi, Georgia's capital.

Previously, the oldest evidence of winemaking was found in the Zagros Mountains of Iran, and dated to between 5500 B.C. and 5000 B.C. The new discovery, dated to 6000 B.C., shows that people were enjoying the alcoholic drink a good 600 to 1,000 years longer than formerly thought, the researchers said. [Raise Your Glass: 10 Intoxicating Beer Facts]

During the excavation in Georgia, researchers uncovered fragments of ceramic jars. While analyzing the chemical residue on shards from eight large jars, the scientists found tartaric acid, a fingerprint compound of grapes and wine.

"We believe this is the oldest example of the domestication of a wild-growing Eurasian grapevine solely for the production of wine," study co-researcher Stephen Batiuk, a senior research associate in the Department of Near and Middle Eastern Civilizations and the Archaeology Centre at the University of Toronto, said in a statement.

During the Neolithic period, people began settling into permanent villages, farming crops, domesticating animals, making polished stone tools and developing crafts, such as pottery and woven goods. These new technologies likely helped ancient people with winemaking, the researchers said.

"Pottery, which was ideal for processing, serving and storing fermented beverages, was invented in this period together with many advances in art, technology and cuisine," Batiuk said.

Moreover, there are more than 10,000 varieties of table and wine grapes worldwide, and "Georgia is home to over 500 varieties for wine alone, suggesting that grapes have been domesticated and cross-breeding in the region for a very long time," Batiuk said.

A number of analyses — including archaeological, chemical, botanical, climatic and radiocarbon — indicate that the Eurasian grape known as Vitis vinifera was abundant at the two Neolithic sites. This grape likely had ideal growing conditions in these Neolithic villages, which had conditions close to those of the modern wine-producing regions of Italy and France, the researchers said.

It's no surprise that once ancient farmers domesticated the grape, wine culture followed, Batiuk added. These ancient societies were awash in wine, which permeated nearly every aspect of life, including medical treatments, special celebrations and everyday meals.

"As a medicine, social lubricant, mind-altering substance and highly valued commodity, wine became the focus of religious cults, pharmacopeias, cuisines, economics and society throughout the ancient Near East," Batiuk said.

Viniculture is complex; it includes domestication, propagation, selection of desirable traits, wine presses, suitable containers and proper closures (such as modern-day corks), the researchers wrote in the study, which was published online today (Nov. 13) in the journal Proceedings of the National Academy of Sciences. And now, people living in the South Caucasus have reason to be proud of the history within their region.

"The Eurasian grapevine that now accounts for 99.9 percent of wine made in the world today has its roots in Caucasia," Batiuk said.

Original article on Live Science.

Drinking alcohol, even a light or moderate amount, increases the risk of several common cancers, according to a leading group of cancer doctors.

This week, the American Society of Clinical Oncology (ASCO) issued a statement identifying alcohol as a "definite" risk factor for cancer. The statement is intended to raise awareness about the strong link between alcohol and cancer.

"People typically don't associate drinking beer, wine and hard liquor with increasing their risk of developing cancer in their lifetimes," Dr. Bruce Johnson, the president of ASCO, said in a statement. Indeed, a recent survey from the organization found that 70 percent of Americans didn't know that drinking alcohol is a risk factor for cancer.

"However, the link between increased alcohol consumption and cancer has been firmly established," Johnson said. [10 Do's and Don'ts to Reduce Your Risk of Cancer]

It's estimated that, worldwide, about 5 percent of new cancers and 6 percent of cancer deaths each year are directly attributable to alcohol consumption, the ASCO statement said.

The statement also cites a recent report from the World Cancer Research Fund and the American Institute for Cancer Research, which concluded that there is convincing evidence that drinking alcohol can be a cause of seven cancers. These include breast cancer, colorectal cancer, esophageal cancer, liver cancer and cancers of the oral cavity, pharynx and larynx (also referred to as "head and neck cancer").

Drinking even one alcoholic drink per day is linked with a 5 percent increase in the risk of breast cancer, a 17 percent increase in the risk of oropharyngeal cancer (a cancer of the middle part of the throat) and a 30 percent increase in the risk of esophageal cancer, compared with not drinking, according to a 2013 study cited by the ASCO statement.

Heavier drinking is linked with greater risks, the statement said. People who drink more than four alcoholic drinks a day have five times the risk of cancer of the oral cavity and pharynx, five times the risk of esophageal cancer and two times the risk of liver cancer, compared with those who don't drink.

"The good news is that, just like people wear sunscreen to limit their risk of skin cancer, limiting alcohol intake is one more thing people can do to reduce their overall risk of developing cancer," said Dr. Noelle LoConte, an associate professor of medicine at the University of Wisconsin and lead author of the ASCO statement.

For people who choose to drink alcohol, the Centers for Disease Control and Prevention recommends that men consume no more than two drinks per day and women consume no more than one drink per day to reduce the risk of alcohol-related harms, including cancer.

ASCO's statement also offered some recommendations to reduce excessive alcohol consumption in the general population, including increasing alcohol taxes and prices, enhancing enforcement of laws that prohibit the sale of alcohol to minors, restricting youth exposure to alcohol-related advertising and providing alcohol screening in doctors' offices.

Original article on Live Science.

If you give a mouse a cookie, you'll prompt it to seek something else, according to the popular children's book. Scientists recently observed similar behavior in experiments with rats — though the rewards were substantially less child-friendly.

In a study examining the effects of addictive substances, researchers gave a group of rats daily servings of alcohol over 10 days, and then introduced the rats to cocaine, which the rodents were allowed to self-administer intravenously by pressing a lever. They found that the rats that were exposed to alcohol responded to the cocaine with the unusual avidity that is typically associated with addiction. 

Further investigation revealed that the rats' long-term alcohol consumption affected brain activity in the region linked to reward-based memory, offering important evidence that alcohol use could be a contributor to the neurochemical landscape that makes some individuals more prone to addictive behavior. [America's Opioid-Use Epidemic: 5 Startling Facts]

Because the study was done in animals, more research is needed to determine whether the same mechanisms are at play in human brains.

Not all cocaine use leads to addiction in humans — only about 21 percent of those who use the drug develop a dependency, the study authors reported. Experts define addiction to cocaine through a set of complex behaviors: when users are more motivated to seek out the drug, when they seek it persistently even when it doesn't cause the same feelings of reward in the brain, and when they continue to pursue it even when there are negative consequences, the researchers wrote in the study.

In the experiments, the rats that had been exposed to alcohol over the 10-day period sought cocaine much more frequently than those that had received no alcohol. During a "time out" period, when no cocaine was released to them, the rats that had received alcohol pressed the drug-delivering lever an average of 58 times. By comparison, the rats that had not received alcohol pressed the lever only 18 times.

The rats that had previously received alcohol also worked harder for their cocaine hit. When the researchers increased the number of presses that the lever required in order to dispense the cocaine, the rats that hadn't been given alcohol pressed the lever up to 310 times, while the group that received alcohol kept on pressing up to 563 times.

Behavioral differences between the groups also emerged during tests to see whether electric shocks to the rats' feet could deter them from seeking cocaine. The rats that had been given alcohol "were significantly more resistant to punishment," the study authors wrote.

On a molecular level, the scientists noted that, in the rats that were exposed to alcohol, two proteins in their brains — nuclear histone deacetylases, known as HDAC4 and HDAC5 — showed decreased activity, which made the brain more responsive to cocaine's effects.

While many factors are associated with cocaine addiction in people — including environmental and genetic variables, in addition to psychiatric disorders — the study's findings suggest that sustained alcohol use could alter the landscape of the brain's reward system, making the user more vulnerable to developing an addiction to cocaine, the researchers said.

The findings were published online Nov. 1 in the journal Science Advances.

Original article on Live Science.

Life expectancy in the United States ticked upward between 2000 and 2015, but that rise was blunted by increasing rates of opioid-related deaths, a new report finds.

Overall, life expectancy at birth increased by 2 years between 2000 and 2015, the report found. The life expectancy for a person born in the U.S. in 2000 is 76.8 years, compared with 78.8 years for a person born in the U.S. in 2015.

Much of this increase in life expectancy can be attributed to a decrease in death rates from the leading causes of death in the country, including heart disease, cancer and stroke, according to the report, which was published today (Sept. 19) in the journal JAMA. Lower rates of death from these causes and several others contributed to a increase in life expectancy of more than 2 years, the researchers found. [America's Opioid-Use Epidemic: 5 Startling Facts]

But increasing death rates from other causes cut into this gain in life expectancy, according to the report. These causes included Alzheimer's disease, suicide, chronic liver disease, septicemia (a blood infection) and, most notably, unintentional injuries — a category that includes drug overdoses.

Drug-overdose deaths increased from about 17,400 deaths in 2000 to about 52,400 deaths in 2015, the researchers said, and the majority of these deaths were due to opioids. Drug-overdose deaths contributed to a decrease in life expectancy of 0.28 years, with opioid-related deaths accounting for 0.21 years of life expectancy lost, according to the report.

In fact, the loss of life expectancy from drug overdoses was as big as the loss of life expectancy from Alzheimer's disease, suicide, chronic liver disease and septicemia combined, according to the report. The reason the overall loss of life expectancy isn't larger, however, is that death rates from other types of unintentional deaths, such as car accidents, decreased over the course of the study period.

In addition, the researchers noted that the change in life expectancy due to opioid-overdose deaths is "likely an underestimate." This is because up to 25 percent of death certificates for drug-related deaths don't mention a specific drug, according to the report.

Between 2000 and 2014, the annual average increase in U.S. life expectancy has been 0.15 years, which is less than the annual average increase in life expectancy of 0.2 years that was recorded between 1970 and 2000, according to the report. And from 2014 to 2015, life expectancy in the U.S. decreased, the researchers said. Currently, life expectancy in the U.S. is lower than life expectancy in most other high-income countries, but preventing opioid-related deaths could help achieve larger increases in life expectancy once again, the researchers said.

To calculate life expectancy, the researchers used data from the National Vital Statistics System Mortality file, a database that contains death certificates from all 50 states and the District of Columbia. 

Originally published on Live Science.

Whiskey connoisseurs have long thought that mixing a few drops of water with the drink could enhance its flavor.

Now, a new study reveals a scientific explanation for why that may be true.

This finding could also help improve the effectiveness of medicines that include alcohol in their ingredients, such as cough syrups, said study lead author Björn Karlsson, a computational chemist at Linnaeus University in Sweden.

It could "have consequences for how we administer and design liquid drug formulations," he told Live Science.

Strong spirit

Whiskey, also spelled "whisky," stems from the Gaelic word "uisge," meaning "water." Whiskey is a powerful alcoholic spirit distilled from fermented grains, typically barley or rye. (In the United States, bourbon whiskeycontains at least 51 percent corn.) It is often aged in wooden casks, and grains may be smoked over peat prior to fermentation to impart a smoky flavor.

Many historical figures have waxed poetic over whiskey. For instance, playwright George Bernard Shaw opined that "whisky is liquid sunshine," while author Mark Twain thought "too much of anything is bad, but too much good whiskey is barely enough." [11 Interesting Facts About Hangovers]

Before whiskey is bottled, water is often added to it to dilute it to about 40 percent alcohol by volume, in the belief that doing so significantly changes its flavor, Karlsson said. Whiskey enthusiasts also often add a few drops of water to whiskey before drinking it to enhance its taste. But how dilution might achieve this effect was not clear until now.

Flavor on top

To help solve this mystery, Karlsson and his colleague Ran Friedman, also at Linnaeus University, carried out computer simulations of water and alcohol. The simulations also included organic compounds associated with the flavor of whiskey. Many of these molecules are so-called amphipathic molecules, which have both water-repelling and water-attracting regions.

The researchers focused on a small amphipathic compound known as guaiacol. This molecule is linked with the smoky taste that develops when malted barley is smoked on peat fires, and is far more common in Scottish whiskies than in American or Irish ones, the researchers said.

When the computer models diluted whiskey to just 45 percent alcohol, guaiacol was more likely to be present at the surface of the whiskey than in the bulk of the liquid. This would help the guaiacol better contribute to both the smell and taste of the spirit at this interface between the fluid and the air, the researchers report online Aug. 17 in the journal Scientific Reports.

In contrast, at concentrations of alcohol above 59 percent, guaiacol was driven away from the surface of the whiskey. The researchers said they expect similar results with other flavor molecules found in whiskey, such as vanillin, found in vanilla extract, and limonene, found in lemon and orange oils.

This work could help optimize the alcohol concentrations of other spirits, such as gin, rum and brandy, Karlsson said. It could also influence how much water and alcohol are used in medicines, the researchers added.

Original article on Live Science.

Can Beyoncé ever catch a break?

The singer and mom to 2-month-old twins Sir and Rumi Carter posted photos to her Instagram account last weekend that showed her and her husband, rapper Jay-Z, sipping on what looks like wine or liquor.

The photos prompted cries of outrage that Beyoncé might be drinking alcohol while breast-feeding. (It's not clear if the singer is currently breast-feeding the twins; she told People magazine after giving birth to her first child, Blue Ivy, that she breast-fed for 10 weeks.) [Beyoncé Expecting 2: Here Are 5 Fun Facts About Twins]

But is drinking alcohol while breast-feeding dangerous for the baby?

It's true that alcohol can be found in a woman's breast milk after drinking, according to theAmerican Academy of Pediatrics (AAP). Because of this, the AAP advises women to avoid habitual alcohol consumption when breast-feeding. 

But an occasional drink is OK, especially if a woman has the drink after she's just nursed or pumped, the AAP says. Women should wait at least 2 hours per alcoholic drink before breast-feeding or pumping milk; this way, the body has as much time as possible to rid itself of the alcohol, the AAP says. One drink is equivalent to a 12-ounce (350 milliliters) beer, a 4-ounce (120 mL) glass of wine or 1 ounce (30 mL) of hard liquor.

La Leche League International (LLLI), a nonprofit breast-feeding advocacy group, agrees that an occasional drink is OK for a breast-feeding mom. "When the breast-feeding mother drinks occasionally or limits her consumption to one drink or less per day, the amount of alcohol her baby receives has not been proven to be harmful," LLLI says.

The amount of alcohol found in breast milk peaks about 30 to 60 minutes after the mother drinks alcohol, and about 60 to 90 minutes after she drinks if the woman has a drink with food, LLLI says. For a woman who weighs 120 lbs. (54 kilograms), it would take from 2 to 3 hours for her body to eliminate the alcohol completely from a serving of beer or wine, the group says, and a high-alcohol drink could take up to 13 hours to clear from the body.

The backlash aimed at Beyoncé isn't unique to celebrities: More than 60 percent of mothers of young children say that they've been criticized for their parenting decisions, according to a survey from the University of Michigan from June. 

Originally published on Live Science.