WebMD Feature from "Prevention" Magazine
Experts reveal the truth behind the most popular (and persistent) health rumors stressing you out
Does reading in low light really hurt your eyes? How about sitting too close to the TV? (No, and no.) Why are you better off drinking exactly eight glasses of water per day? (You're not.) Thanks to quack culture, the Internet, and well-intentioned but poorly informed relatives, it's become harder than ever to separate fact from fiction. Whatever its origin, misleading health information can cause unnecessary anxiety and distract you from wellness habits that truly deserve your energy and attention. Here's a dissection of six watercooler myths that will give you all the authority you need to refute your brother's latest forwarded e-mails.
CELL PHONES are dangerous to use in hospitals because they can interfere with medical equipment.
Verdict: JURY'S OUT. There's a chance that a cell phone call in the wrong spot can cause ventilators, syringe pumps, or even pacemakers to pulse incorrectly, according to a 2007 Dutch study. The researchers tested modern cell phones, including PDAs that use wireless Internet signals. After placing the phones just a few centimeters from devices, researchers found that 43% of the phones caused electromagnetic interference with critical care equipment--and a third of those instances could be potentially life-threatening to patients. But those findings countered a Mayo Clinic study a year prior that found no instances of "clinically important" interference between cell phones and medical machines. In fact, Mayo researchers advised hospitals to revise or drop their cell phone bans.
Bottom Line: Play it safe for now: Use a designated cell phone area at the hospital, which most now offer--or use a call as an excuse for a walk-and-talk outside for some fresh air and exercise. If you feel compelled to stay by a relative's side in the ER or recovery room, make sure to carry a good old-fashioned calling card to use at a pay phone.
IT'S SAFE to follow "the 5-second rule" for food dropped on the floor.
Verdict: FICTION. It's probably not even safe to follow a 1-second rule: The transfer of bacteria from a contaminated surface to food is almost instantaneous--or, at the very least, quicker than your reflexes. In a recent study,
Bottom Line: There are 76 million cases of foodborne illness annually in the
CRACKING your knuckles can cause arthritis.
Verdict: FICTION. If you're suffering from osteoarthritis in your hands, it certainly has nothing to do with this nervous tic. One study at the former
Bottom Line: Try turning your nervous energy into a less harmful habit that occupies your hands (such as doodling). If a different activity doesn't get you to stop, try putting a large rubber band around your wrist and every time you catch yourself cracking your knuckles, pull it back and let it snap as a reminder that your habit really can be harmful. Most important, get to the bottom of what's causing your nervousness in the first place--you may crack your knuckles more often at work than at home, for example--and address those sources directly.
COLA-TYPE soft drinks can damage your kidneys.
Verdict: FACT. Despite their global popularity, there's nothing remotely healthy about cola beverages: Drinking 16 ounces or more daily (whether diet or regular) doubles your risk of chronic kidney disease, according to a recent NIH study of more than 900 people. The researchers already knew that consuming any type of soft drink--the average American adult guzzles 59 gallons' worth per year--is associated with several risk factors for kidney disease (hypertension, diabetes, and kidney stones), but the spike in the cola category was remarkable. Experts suspect that the ingredient phosphoric acid may be the culprit; it's been repeatedly linked to "urinary changes that promote kidney stones," say the study authors. Cola has an additional knock against it: Consumption is associated with significantly lower bone density in women, increasing the risk of osteoporosis and bone fractures, says a separate study.
Bottom Line: If you're going to indulge in an occasional soda, go for Sprite, 7-Up, ginger ale, and the like--the NIH study found that noncola drinks didn't have the same impact on the kidneys. But you'll be better off if you skip soda altogether, even the sugar-free varieties: Recent research showed an association between drinking diet soda and weight gain.
"DOUBLE-DIPPING" spreads germs from one chip to another.
Verdict: FACT. In a classic episode of Seinfeld, a partygoer accused George Costanza of spreading germs by "double-dipping"--swiping a chip into a bowl of dip, taking a bite, and then dipping the same chip again. Having settled the 5-second rule debate,
Bottom Line: You'd better be pretty comfy with your party guests. "Eating from a dip after someone has dipped twice is basically the same as kissing that person,"
EATING locally produced honey can ease seasonal allergies.
Verdict: JURY'S OUT. The theory seems sound: Bees in your neighborhood feed on the same pollen that gives you itchy eyes and a runny nose. That pollen gets added to the hive's honey, and ingesting it helps you build a tolerance to those allergens--or so the thinking goes. But does this really work? "We don't know--there are no studies to support it, only testimonials," says Leonard Bielory, MD, director of the Asthma and
Bottom Line: Keep standard allergy remedies on hand, but feel free to enjoy local honey, too--it's a worthy replacement for other sweeteners and even has natural antibiotic properties.