Science is supposed to make people's lives better, right? From glow-in-the-dark diapers to computers that fit in one's pocket, the present day sometimes feels like a future dreamed by science-fiction writers. But scientific research also dramatizes the law of unintended consequences, such as the increased chance that the late-night user of an iPhone will become obese.
Here are 10 buzzkills in science – studies sure to ruin your fun.
1. Sharing a bed with your dog or cat is a bad idea. (And no kissing!)
Sleeping with pets is a good way to get the plague, or MRSA, meningitis, hookworm, roundworm or another bacterial infection, according to a study published in February 2011 in the journal Emerging Infectious Diseases. The authors also report several pet owners contracted disease when their mouth or an open sore was lovingly licked by their animals.
One man whose dog slept under the covers with him and licked his hip-replacement wound came down with meningitis, and a 9-year-old boy whose flea-infested cat slept with him picked up the plague. The authors, a professor of veterinary medicine at the University of California, Davis, and a public health veterinarian for the California Department of Health, say keeping pets healthy through regular veterinary care can reduce the risk. [See What Your Dog's Breed Says About You]
2. No snacking on raw cookie dough.
Raw cookie dough from the store seems so yummy and so safe: The eggs in commercial cookie dough are pasteurized, which kills Salmonella. Many people admit buying a tube with no plans to actually bake cookies, according to a study published in December 2011 in the journal Clinical Infectious Diseases.
But a party-crashing study, which tracked the source of a large E. colioutbreak in 2009, ultimately blamed the flour in raw chocolate chip cookie dough for the infection. "Out of all the ingredients, raw flour is the only raw agricultural product that was in the cookie dough," study author Karen Neil, a medical epidemiologist with the Centers for Disease Control and Prevention, said. Apparently, there's just no safe way to sneak a bite of cookie dough unless it's enrobed in ice cream.
3. Exercise won't help you lose weight.
And if you plan on baking that cookie dough and downing the delectable calories, you can always spend a few extra minutes later at the gym, right? Wrong. Two recent studies put a damper on the theory that exercise will help you lose weight. A person's basal metabolic rate, which determines how many calories get burned daily, will drop as you lose weight, even with daily exercise, the research showed. The conclusion: Eating less leads to faster and more weight loss than increasing exercise does. (Still, regular exercise is important for your overall health.) [The 7 Biggest Diet Myths]
4. Keep your iWhatever off at night.
Chronic exposure to light at night is linked to an increased risk of breast cancer, obesity and depression, so keep the TV, computer and phone turned off at night. That's harder than it sounds for the average American. The National Sleep Foundation reports 95 percent of Americans use some sort of technological device at night, with 49 percent or more turning on the television in the hour before sleep. And more than half, 56 percent, of Generation Z (ages 13-18) and nearly half, 42 percent, of Generation Y (ages 19-29) say they text in the hour before bed.
Artificial light exposure before sleep disrupts the body's natural rhythms, and it suppresses the hormone melatonin, which promotes sleep, according to the American Medical Association. In June the group adopted a policy recognizing the adverse effects of exposure to excessive light at night, including extended use of various electronic media
5. Watch out: Tanning is addictive.
Keeping a healthy glow can mean heading to a tanning salon. Not so fast. Such indoor bronzing can become an addiction. People who use tanning beds show changes in the brain's reward centers that mimic the patterns of drug addiction. And CT scans have shown that tanners' brains can tell the difference between UV light and sham tanning beds, according to an May 2012 study in the Journal of Addiction Biology.
What about spray tanning? Research suggests this seemingly safe alternative to tanning beds may not be risk-free, as the sprays carry chemicals that cause genetic mutations to cells in a lab dish. Human studies have yet to validate the lab-dish findings.
6. Drop your SquarePants?
If you want a calm kid who can control her or his behavior, think about turning off "SpongeBob" and turning on the slower-paced "Caillou." For 4-year-olds, watching just nine minutes of the fantasy cartoon "SpongeBob SquarePants" compromised their ability to learn and to behave with self-control. Kids who watched "Caillou" or who entertained themselves by drawing showed little effect. But don't put all the blame on SpongeBob. University of Virginia psychology professor Angeline Lillard, the lead author, said similar problems occur in kids who watched other fast-paced cartoons. The study was detailed Sept. 12, 2012, in the journal Pediatrics.
7. Double dipping is more than a party foul.
Yes, George Costanza, dipping the same chip twice truly spreads germs. Clemson University researchers, inspired by a 1993 "Seinfeld" episode, tested the amount of bacteria transferred to salsa, chocolate sauce and cheese by a double-dipped chip. On average, about 10,000 bacteria traveled from the eater's mouth to the dip, meaning another dipper would get at least 50 to 100 bacteria from the offender's mouth in every bite. Their study was published in the January 2009 issue of the Journal of Food Safety.
8. Soda makes you fat. Will more cities take away your Big Gulp?
It's finally been confirmed: Sugary drinks make you fat. Whether the liquid is soda, lemonade or a fruit drink, children, teens and adults who imbibe even modest amounts gain excess weight, according to a trio of studies published in the Sept. 21, 2012, issue of the New England Journal of Medicine. What's new here is the finding that if your genes put you at a heightened risk of obesity, you're also more likely than others to put on pounds from sugary drinks. The studies could mean more cities will imitate New York City, which recently banned large sugary drinks.
9. Vitamins increase your risk of dying.
It's hard to argue with results from 200,000 people: Not only do vitamin supplements do nothing to prolong life, they also appear to actively increase your risk of dying, albeit indirectly. This conclusion, from a 2010 Cochrane review of randomized trials, was so astonishing that researchers set out to confirm it with a longer study. And confirm it they did: Vitamins create "illusory invulnerability," the authors reported in the August 2011 issue of the journal Psychological Science. For example, people taking vitamins chose a buffet over an organic meal and exercised less.
10. Yes, you can drink too much coffee.
Setting aside the acidic effect on your stomach lining, drinking too much coffee is risky for your health. How much coffee is too much? Studies say seven cups a day can cause anxiety, irritability, sleeplessness and even hallucinations. Drinking 10 or 11 cups daily slightly raises your risk of heart failure. Yet some people carry genetic mutations that increase their metabolism of caffeine. Others have a genetic quirk that slows the breakdown of the drug. Thus, how quickly you metabolize coffee determines your health risk.