25 Odd Facts About Marijuana
1 of 26
Marijuana, the most commonly used illegal drug in America, is going mainstream. It's now legal to use marijuana recreationally in eight states — Alaska, California, Colorado, Oregon, Maine, Massachusetts, Nevada, Washington — and the District of Columbia. Pot seems poised for wider use, too: There are 21 states that now allow the possession and use of marijuana for medicinal purposes, according to the National Institute on Drug Abuse.
But just how much do you know about the wacky weed and its odd effects? How exactly does marijuana provide its high, and who discovered the effects of smoking the plant in the first place? Read on for some of the stranger facts about cannabis consumption.
2 of 26
The hippie generation did not discover pot. But the drug's true origins remain a bit murky.
For example, one source, the Drug Enforcement Administration Museum in Arlington, Virginia, states that the oldest written references to cannabis date back to 2727 B.C., when the Chinese Emperor Shen Nung supposedly discovered the substance and used it medicinally.
But there's one problem with this putative fact: Shen Nung, if he existed, was not the emperor of China. The first emperor of a unified China was Qin Shi Huang, who was born around 260 B.C. — significantly later than the supposed Shen Nung. Nor is it entirely clear where or how this Shen Nung recorded his medicinal marijuana experiments. The earliest examples of written Chinese characters date to the Shang dynasty, between 1200 B.C. and 1050 B.C., when oracles carved symbols on bones and turtle shells. Though the story of Shen Nung permeates pot histories online, his existence seems to be more marijuana myth than fact.
Still, the Chinese deserve some credit. The ancient Taiwanese were using hemp fibers to decorate pottery about 10,000 years ago, according to "The Archaeology of Ancient China" (Yale University Press, 1968).
But the identity of the first person to discover pot's intoxicating effects is lost to prehistory.
3 of 26
Weird ways to use hemp
The marijuana plant isn't used only for smoking; its fibers can also be made into rope or fabric. Perhaps the oddest use of hemp rope on record is as a method for transporting giant stone statues. In 2012, archaeologists created reproductions of Easter Island's statues, trying to figure out how ancient people may have moved the iconic 9,600-lb. (4.35 metric tons) heads from their quarry. Theorists have suggested everything from log rollers to extraterrestrial help for the task, but in 2012, California State University Long Beach archaeologist Carl Lipo proved that all that was needed is hemp rope.
By attaching three hemp ropes to the statue and having a team of 18 people rock it back and forth until it "walked," Lipo and his team were able to move the hunk of stone 328 feet (100 meters) in less than an hour, they reported in the Journal of Archaeological Science. Easter Islanders would have had woody shrubs similar to marijuana plants to use in making rope, the researchers argued.
4 of 26
Hemp versus pot
What's the difference between hemp and pot, anyway? A single genetic switch. In 2011, researchers from the University of Saskatchewan announced that they'd discovered the genetic alteration that allows psychoactive cannabis plants (Cannabis sativa) to give users a high (as compared to industrial hemp plants, which are no fun for smoking).
Industrial hemp plants are the same species as marijuana plants, but they don't produce a substance called tetrahydrocannabinolic acid (THCA). This is the precursor to tetrahydrocannabinol (THC), the psychoactive ingredient in pot. Hemp plants fail to produce this substance because they lack a gene that makes an enzyme to produce THCA, according to University of Saskatchewan biochemist Jon Page.
In contrast, marijuana plants do produce THCA but don't create much of a substance called cannabidiolic acid (CBDA), which occurs in abundance in hemp but competes with THCA for raw materials. Thus, hemp is rich in nonpsychoactive CBDA, while marijuana is chock full of mind-bending THC.
5 of 26
Smoking up could be a very different experience for men and women, according to a 2014 study in the journal Drug and Alcohol Dependence. In research on rats, Washington State University psychologist Rebecca Craft found that females were more sensitive to cannabis' painkilling qualities, but they were also more likely to develop a tolerance for the drug, which could contribute to negative side effects and dependence on marijuana.
The female rats' higher levels of the hormone estrogen seem to play a role in these sex-specific effects. Female rats are more sensitive to the effects of cannabis at ovulation, when estrogen levels are highest, Craft said in a statement.
6 of 26
Pot for your pets?
People have used medicinal marijuana to ease everything from glaucoma to the side effects of chemotherapy. So why shouldn't man's best friend give medicinal pot a shot?
Pet owners are already using marijuana medicinally to help their suffering cats and dogs, according to a 2013 article in the Journal of the American Veterinary Medical Association. Most of the time, animals that ingest pot get over the effects within a few hours, veterinarians say. But in large quantities, pot can be deadly to animals.
7 of 26
Does your heart hate pot?
Most of the debate about the health effects of marijuana centers on the brain changes that may come with using the drug, such as the drug's association with an increased risk of developing schizophrenia and other psychotic disorders. But could smoking a bowl mess with your heart, too?
In an April 2014 study, researchers combed through 2,000 cases of medical complications from marijuana in France and found that 2 percent involved heart problems, including nine fatal heart attacks. The study wasn't designed to determine why pot use might occasionally lead to heart problems, but previous research has found that marijuana can increase heart rate and blood pressure, which could tip a vulnerable individual over into heart attack territory.
"The perception is that marijuana is a magical drug, that it's totally safe, and we can use it in medical treatment. What we don't know about are the negative effects, the potential harms," Dr. Suzanne Steinbaum, a cardiologist at Lenox Hill Hospital in New York who was not involved in the study, told Live Science at the time.
8 of 26
A wine lover might choose between a pinot noir, a sangiovese and a viognier to go with dinner. A pot connoisseur, on the other hand, could choose between strains with names like "purple haze," "chocolope" and "green crack."
Bizarre names are a time-honored tradition among pot growers, going back at least to the 1970s, when strains such as "Maui Waui" (from Hawaii, naturally) came onto the scene. Why such goofy names? Well, one reason might be the process behind the naming decisions.
"So many times, we've finally got to the end of a strain, and we have it right there and it's done, and we're like, 'What do we call it?'" one of the co-owners of Amsterdam's DNA Genetics, a cannabis seed bank, told the LA Times in July 2014. "And we sit there, and we call all our friends and smoke. That's a brainstorm session."
9 of 26
It's in the air
There are certain places where a haze of pot smoke is to be expected: Grateful Dead concerts, for example, or marijuana legalization rallies. But on the streets of Rome?
Yes, according to a 2012 study done in Italy, trace amounts of marijuana are wafting through the air around the Colosseum and the Pantheon, as well as in seven other Italian cities. Researchers examined the air of Rome, Bologna, Florence, Milan, Naples, Palermo, Turin and Verona for psychotropic substances, including cocaine, marijuana, nicotine and caffeine. The scientists found all of these substances in all eight cities, with Turin having the highest total concentrations and Florence and Bologna having the highest concentrations of pot.
But even in Florence and Bologna, tourists don't need to worry about a contact high while taking in the sights. The levels of marijuana and other substances were far too low to affect human health — but researchers said they hope the findings can inform drug policy by helping to estimate drug consumption in each city.
10 of 26
Baby soap oops
In an unusual case, a hospital in North Carolina noticed an uptick in the number of newborns who were testing positive for marijuana in their urine, a finding that can suggest that mom has been smoking and can lead to social services getting involved. But it turns out that these babies weren't suffering from pot exposure. They were just soapy.
An investigation of the positive tests found that ingredients in several common baby soaps can cause a false positive on marijuana urine tests, researchers reported in 2012. The soaps, including formulas from Johnson & Johnson, CVS and Aveeno, don't contain pot, nor do the get infants high. A more sensitive test can show that the initial screening results were false positives, researchers reported in the journal Clinical Biochemistry.
11 of 26
Pot isn't necessarily green
Here's a bummer for the eco-conscious: Pot isn't all that "green." The energy needed to produce 2.2 pounds (1 kilogram) of marijuana indoors is equivalent to that needed to drive across the country five times in a car that gets 44 miles to the gallon, according to a 2011 report by a researcher at Lawrence Berkeley National Laboratory. All those grow lights suck up a lot of electricity.
Growing plants outdoors could lessen marijuana's carbon footprint, but year-round demand for the drug means that industrial growers keep their plants in warehouses and greenhouses. Innovations such as greenhouses equipped with low-energy LED lights could help make pot greener, but like any large-scale agriculture, marijuana growing will require large-scale energy.
12 of 26
Pot versus owls?
Outdoor grow operations have their downsides, too — particularly illegal plots of pot plants. Endangered spotted owls in California's Mendocino County are threatened by the rat poison put out by people who grow pot illegally on isolated stretches of public land. In 2012, two spotted owls found dead in Mendocino County tested positive for rat poison, as did the bodies of 85 percent of dead mammals called fishers.
The people who harvest illegal pot can find themselves with health problems, too. In June 2013, hospital workers in Albania reported a cluster of marijuana-related illnesses, with more than 700 patients treated at one village. Workers near the village of Lazarat who had prolonged skin contact with cannabis plants during harvesting and packing developed symptoms such as vomiting, stomach pain and irregular heartbeats, according to Reuters. Half of Albania's marijuana is grown illegally in the region.
13 of 26
Pot is getting stronger
Marijuana's high is getting increasingly higher. In 2016, researchers measured the levels of marijuana's active ingredient, THC, in more than 38,600 samples of street marijuana seized by the Drug Enforcement Agency over 20 years. They found that the levels of THC rose from about 4 percent in 1995 to about 12 percent in 2014.
Meanwhile, levels of the non-psychoactive compound cannabidiol fell from 0.28 percent in 2001 to 0.15 percent in 2014, the researchers reported in the journal Biological Psychiatry. As a result, THC levels were 14 times the level of cannabidiol in 1995; in 2014, that ratio had grown to 80.
THC intensifies the effects of marijuana, the researchers said, so higher THC versions of the drug may raise the risk of nasty side effects, like panic or anxiety. More THC also means pricier pot, which is one reason growers have been cultivating higher octane strains.
14 of 26
Controversy over cardiac deaths
It's not possible to overdose on marijuana like you can on heroin or cocaine. But in 2014, German researchers caused a controversy when they linked the sudden deaths of two men to cardiovascular complications from pot smoking. The cases were unusual. In one, a seemingly healthy 23-year-old man collapsed and died on public transportation with marijuana in his pocket. In the other case, a 28-year-old man was found dead with rolling papers and a plastic baggy of marijuana at his side. Both men were found to have THC, the psychoactive ingredient in marijuana, in their tissues at a postmortem.
"After exclusion of other causes of death, we assume that the young men died from cardiovascular complications evoked by smoking cannabis," the researchers wrote.
Responding to the findings, outside researchers said at the time that the conclusions were reasonable, given research on the cardiovascular effects of marijuana. However, the case reports caused intense public controversy and prompted "some quite unpleasant reactions from individuals," the study researchers told Live Science.
15 of 26
You can be allergic to pot
Aaa-chooo! Like many other plants, marijuana can trigger allergic reactions in people, according to a 2015 review in the journal Annals of Allergy, Asthma & Immunology. Both the plant's pollen and its smoke can cause allergies in some people, the researchers said. Marijuana allergies are relatively rare, they wrote, but they're on the rise and have probably been underreported or unnoticed because the drug has long been illegal.
Most of the reported symptoms of pot allergies are similar to those of run-of-the-mill hay fever: itchy eyes, coughing, sneezing, occasional hives. However, there have been a few reported cases of people having anaphylactic reactions to hemp or marijuana. Anaphylaxis is a life-threatening response to an allergen that can cause the airways to swell shut.
16 of 26
Is pot addictive? Ask your genes
For a subset of pot users, marijuana becomes a substance of dependence. This means that they experience symptoms of withdrawal, such as irritability and restlessness, when they attempt to stop using the drug. There is academic debate over how many people should be considered dependent on marijuana, but national epidemiological studies put the rate at about 9 percent of users, according to the National Institute on Drug Abuse.
Marijuana dependence may have genetic underpinnings. A 2016 study uncovered three genetic variants associated with dependence. One variant is involved in regulating calcium in the blood and has been linked with opioid dependence; another is involved with the growth of the central nervous system, the researchers reported in the journal JAMA Psychiatry. The genetic variations were simply associated with dependence, and the study couldn't prove that having one of these variants caused dependence. Nevertheless, the researchers found that the genetic variations they'd discovered also tend to occur in people with depression, which could explain why dependence and depression often go hand-in-hand.
17 of 26
Pot and Viagra don't mix
Marijuana compounds can inhibit certain liver enzymes called cytochrome P450 enzymes. What does that mean? Well, for one thing, that Viagra won't break down as readily in the blood of someone who's been toking up.
Viagra (sildenafil) is broken down by cytochrome P450 enzymes, and as a 2001 study put it, "[t]here is the possibility that elevated plasma concentrations of sildenafil could occur with coadministration of known inhibitors of" these enzymes. This could cause adverse side effects. One 2002 case report in the journal Clinical Cardiology outlined the case of a 41-year-old man who experienced a heart attack after mixing marijuana and Viagra the night before. Though the doctors couldn't prove that a drug interaction caused the heart attack, they warned other physicians to consider the enzyme-inhibiting side effects of pot when they prescribe Viagra.
18 of 26
Back to the Future
In many ways, the move toward legalization of marijuana, particularly medical marijuana, is a return to the status quo … the very long-ago status quo. In America, before the 1906 Pure Food and Drug Act, cannabis was a common ingredient in medicinal tinctures, and sellers didn't even have to mention it on their labels.
During the 1920s and 1930s, though, Mexican immigration to the United States spiked as a result of the Mexican Revolution, according to PBS Frontline. People moving from Mexico brought along the custom of using marijuana recreationally, and the drug became linked with public fears of the newcomers. According to U.S. Customs and Border Protection, the federal government waffled on making marijuana illegal even as states enacted their own laws — a strange mirror image of the legalization process going on today. Nevertheless, Federal Bureau of Narcotics Commissioner Harry Anslinger campaigned to quash recreational marijuana, an effort that led to the Marihuana Tax Act of 1937. This law allowed for the importation of marijuana, but heavily taxed it, making it too expensive for recreational use.
19 of 26
It's well-known that pot can sometimes cause paranoia. But in 2011, doctors reported another possible negative side effect of marijuana: cannabinoid hyperemesis syndrome. Here's a hint as to what that might be — "emesis" is the Latin for "vomiting."
Yes, marijuana use can sometimes lead to episodes of uncontrollable vomiting. The cycle usually has three phases, researchers wrote in the journal Current Drug Abuse Reviews. First, patients (usually chronic marijuana users) develop morning nausea and general abdominal discomfort. But they often increase their marijuana use, hoping for the drug's anti-nausea effects to kick in. Then comes the hyperemesis part. Patients vomit repeatedly, up to five times an hour, for one or two days. The only help is hot showers. It can take days, weeks or even months before the patients recover and get back to normal. Stopping cannabis use can prevent relapse.
But cannabinoid hyperemesis remains otherwise largely mysterious. There's no data on how many people experience it, or why it seems to be a small proportion of pot users, the researchers wrote. There's also no explanation of why marijuana, known for its anti-emetic properties, should have the opposite effect in some people. THC, the psychoactive ingredient in marijuana, has an anti-nausea effect on the central nervous system, the researchers wrote. However, some cannabinoid compounds slow the gut, preventing it from emptying as quickly in the usual way. For some people, this slowdown might override the anti-emetic effect of THC and cause vomiting, the researchers speculated.
20 of 26
In November 2016, California, Massachusetts and Nevada joined Colorado, Alaska, Oregon and Washington in legalizing recreational pot. (Maine's legalization initiative narrowly passed, and opponents were attempting a recount in the week after the election.) An October 2016 study in the journal Drug Records suggests that legalization might not just influence the availability of pot, but how it's consumed.
The researchers looked at about 2,800 people who had used marijuana at least once. The participants were not nationally representative. Still, the study authors found that people in states where marijuana is legal were more likely to have used cannabis by vaping it or by ingesting edibles than people in states where marijuana isn't legal. A higher density of pot shops and a greater amount of time since legalization were also linked to higher rates of vaping and edible consumption.
21 of 26
Drug bust record
The Guinness Book of World Records apparently does not keep any records for the amounts of marijuana grown, smoked or otherwise consumed. But the drug does show up in the record books. The "bulkiest drug seizure" of marijuana ever was 2,903 metric tons, or 6.4 million pounds, that came from a Colombian drug operation. That was one-fifth of the entire illegal import of marijuana into the United States per year at the time, according to a 1982 New York Times article.
This seizure, code-named "Operation Tiburon," also led to the arrests of 495 people and the seizure of 95 boats thought to be used in drug smuggling.
22 of 26
Did the Bard toke?
Maybe you've heard that we owe Hamlet and King Lear to a stoner. In 2001, an anthropologist reported that he'd discovered marijuana residue on the fragments of a pipe found in William Shakespeare's garden in England. Combining that discovery with an aside about a "noted weed" in the playwright's Sonnet 76, the anthropologist asked for permission to open Shakespeare's grave in 2011 and search for signs of cannabis in any hair or fingernails.
That never happened, though a ground-penetrating radar survey in 2016 revealed that Shakespeare's corpse probably doesn't have any hair anyway — his skull is most likely missing.
23 of 26
First transcontinental marijuana trade
The world's first-known pot dealers were the nomads of the Eastern European Steppe, according to a 2016 study.
The Yamnaya, traders from what is now Russia and Ukraine, may have traded cannabis throughout Europe and East Asia around 5,000 years ago, the researchers found. The plant itself was in use in both Europe and Asia at least 10,200 years ago and grew naturally across both continents. But the archaeological record shows a spike in cannabis use in East Asia around 5,000 years ago, right around the time when the nomadic Yamnaya established a trade route across the steppes. Yamnaya sites show signs of cannabis burning, suggesting they may have brought the habit of smoking marijuana with them as they moved about.
24 of 26
Taking it to the grave
Around 2,700 years ago, a 45-year-old man died, probably in the highlands of the Tianshan Mountains in Xinjiang, China. Shortly thereafter, his bones were taken and interred in a cemetery in the Gobi Desert, called Yanghai. Alongside his body, someone placed a bag and a bowl of 28 ounces (789 grams) of Cannabis sativa, according to researchers who studied the remains and wrote about their findings in 2008 in the Journal of Experimental Botany.
Preserved by dry desert conditions, the plant matter was still tinted green, though it didn't have the distinctive cannabis smell. (Nor did its seeds germinate into plants — the researchers tried!) The strain appeared to be domesticated based on the size and shape of its seeds, and a molecular analysis revealed compounds that included cannabidiol, cannabichromene and cannabicyclol. The plant in the bowl had been slightly ground, suggesting that it was being used for "medicinal or mystical attributes," the researchers wrote.
25 of 26
Buried in hemp
Around the same time that the 45-year-old man went to his eternal rest next to a stash of pot, another man in a neighboring cemetery had a similar, if slightly stranger, burial. In October 2016, researchers reported that they'd found the grave of a 35-year-old man who'd been laid to rest under a shroud of cannabis.
The grave was in Jiayi, a cemetery not far from Yanghai, in western China. Its occupant was a Caucasian man lying on a bed of wooden slats. Over his chest were 13 Cannabis sativa plants, draped diagonally from the man's chin to his pelvis. Researchers estimated the age of the burial at between 2,400 and 2,800 years old. It's unclear why the man was buried under a layer of cannabis, but the development of the uprooted plants suggests that he died in August or September.
26 of 26
Getting high might affect how you seen winning and losing. In a 2016 study, participants played a game in which they could win a few cents or lose a few dollars, depending how well they did. As they played, researchers scanned their brains, focusing on a small area called the nucleus accumbens that's responsible for processing rewards.
The study found that people who had used marijuana more showed weaker nucleus accumbens responses to the prospect of winning than people who'd used the drug less. Of course, the study couldn't prove that marijuana use directly caused the brain changes — it could be that there is some third cause of both, or an underlying reason why someone with a lessened reward response might gravitate toward marijuana use, the researchers said.
Original article on Live Science.