Medical Myths Survive Like a Cold You Catch Outside (That’s Another!) : Health: Such misconceptions, rooted in the past, hang on when they support cultural beliefs about illnesses.
Bundle up, or you’ll catch your death of cold. Slice open a snakebite and suck out the venom. Avoid chocolate--it goes right to your face.
Good advice? Hardly, though each is a medical myth cherished by generations of parents and even physicians. It is one of the more telling paradoxes of our time that while we marvel at computerized brain scans, we still teach our kids that toads cause warts. (They don’t; viruses do.) And many people still think ulcer patients should drink milk because bland-tasting foods soothe the stomach. (Not true.)
Why common sense sometimes makes no medical sense is a question that fascinates John Warner, an associate professor of the history of medicine at Yale University. Medical myths, rooted in the past, survive when they support cultural beliefs about health and disease, he says.
Bloodletting, for example, persisted until the time of the Civil War because people believed that disease resulted from an excess of energy in the body. Leeches, the theory went, sapped energy as well as blood and thus brought patients back to tranquillity--if they lived.
After the Civil War, physicians tended to hold that disease was largely a problem of lassitude. So they switched from bleeding to “brandying,” dosing patients with shots of fortified wine to stimulate them.
Ironically, leeches are now making a modest but legitimate comeback. Doctors sometimes use the bloodsucking creatures to drain hematomas (clumps of clotted blood) created by blood vessel injuries.
Today’s prevailing health belief in our culture is that for every disease there must be a “magic bullet”--a simple, direct cure. Indeed, there have been some; penicillin might qualify.
But for the most part, the magic-bullet concept is more faith than fact. Consider these popular misconceptions:
* Bundle up to avoid catching cold. Surprise, there’s no link between cold as in temperature and cold as in sneeze your head off. In repeated experiments at the Common Cold Unit in Salisbury, England, people left shivering out in the cold were no more likely to catch cold than those who stayed warm indoors drinking tea.
There are about 200 cold viruses, says internist Jack Gwaltney, a professor of medicine at the University of Virginia Medical School.
“Unless a virus gets to you in the right place--the eye or nose, and for some viruses, the mouth or throat--you’re not going to catch cold, no matter where you are,” he says.
* Chocolate causes pimples. In the name of medical science, researchers have fed chocolate to scores of youngsters, including acne-prone adolescents and those who swore chocolate made their faces break out. “In none of these studies was there any statistically significant difference in the severity of their acne after the kids were fed even large amounts of chocolate,” says Dr. Andrew Bronin, an associate clinical professor of dermatology at Yale University School of Medicine.
And that’s not all. “There’s no correlation between acne and exercise--either too much or too little,” Bronin says. Nor is there any connection with athletics, unless players wear tightfitting equipment such as helmets or pads that block the pores with sweat.
Extra washing doesn’t help either. “Beyond normal hygiene to get the natural oils off the skin, you can wash a hundred times a day, and it still won’t make a difference.”
Acne occurs when the oil secreted by the skin’s sebaceous glands clogs the body’s pores and bacteria cause inflammation. Breakouts are thought to be linked with increased levels of testosterone; genetics may also play a role.
* Suck a snakebite to prevent poisoning. “Using your mouth to drain out venom is the worst thing you can do,” says Dr. Doug Gentile, an assistant professor of surgery and medicine at Vanderbilt University.
For one thing, cutting the skin around the bite enlarges the injury, and bacteria in your mouth multiply the risk of infection to the wound. Besides, not all poisonous snakes are killers, and not all bites are lethal.
“In a significant percentage of bites,” he says, “no venom at all gets under the skin, because snakes sometimes bite without injecting venom.”
Other misguided snakebite treatments include ice packs, tourniquets and shots of whiskey. Ice can turn snakebite into frostbite. Tourniquets can strangle the blood supply completely so that tissue dies. Alcohol doesn’t help.
The right way to treat a snakebite is to seek immediate medical care, and if the bite is on an extremity, to immobilize it by splinting.
* Hold the mayo--it’s bad for you. It’s under a two-count indictment for being a source of bacterial infection as well as cholesterol. But mayonnaise is misunderstood. Yes, like eggs, chicken, unpasteurized milk and infected pet turtles, mayonnaise can be a breeding ground for salmonella, a nasty intestinal infection.
But fear often outruns reality, according to Karen Miller-Kovach, director of nutrition services at the Cleveland Clinic Foundation.
The vinegar in mayonnaise is acidic enough to block bacterial growth, she says. True, if the mayonnaise is combined in a salad, its protective acidity may be diluted. And you take more of a chance with the mayonnaise you make at home using raw eggs. (Store-bought mayonnaise is made with pasteurized eggs.)
On the second count, mayonnaise contains just five milligrams of cholesterol per tablespoon. According to the American Heart Assn.’s recommendation of no more than 300 milligrams of cholesterol a day, you’d have to eat a lot of mayo to reach your limit.
