Debunking Medical Myths

6 Medical Myths for the Holiday Season - Well Blog - NYTimes.com

Last year, the British medical journal BMJ reported on a series of medical myths that even doctors believe. Among them: Turkey makes you drowsy. Dim light ruins your eyes. Drink at last eight glasses of water a day.

This year, the same researchers, Dr. Aaron Carroll and Dr. Rachel Vreeman of the Indiana University School of Medicine, offer six new medical myths for the holiday season. The latest set of myths, published this month in BMJ, are commonly believed by the general public and many doctors, said the researchers. However, a search of the medical literature shows these myths aren’t true or lack evidence to support them.

“Even widely held medical beliefs require examination or re-examination,” the study authors wrote. “Both physicians and non-physicians sometimes believe things about our bodies that just are not true.”

Here are the six new commonly believed medical myths they’ve identified.

1. Sugar makes kids hyperactive.

The researchers cite 12 controlled studies that couldn’t detect any differences in behavior between children who had sugar and those who did not. Even when kids had a diagnosis of hyperactivity problems or were said to be more sensitive to sugar, they did not behave differently whether they ate sugar-laden or sugar-free diets. In fact, the biggest effect of sugar may be on parents. Parents rate their children as being more hyperactive if they are told the child has consumed sugar — even when the child hasn’t really had any sweets.

2. Suicide increases over the holidays.

Suicides are more common during warm and sunny times of the year, studies show. There is no evidence of a holiday peak in suicides.

3. Poinsettias are toxic.

Among 22,793 poinsettia exposures reported to the American Association of Poison Control Centers, there were no deaths or significant poisonings. A study of poinsettia ingestion found that when rats were given doses equal to a person consuming 500 to 600 poinsettia leaves, the plant wasn’t toxic.

4. You lose most of your body heat through your head.

This is the myth that Dr. Carroll and Dr. Vreeman believed to be true. They found out that the belief likely originated with an old military study where subjects wearing arctic survival suits lost most of their body heat through their heads. But that was because the head was the only bare part of their bodies. Typically, we don’t lose more than 10 percent of body heat through our heads. The bottom line is that any uncovered part of the body will lose heat, which is why wearing a hat, even when you’re bundled up everywhere else, is important.

5. Night eating makes you fat.

Studies show an association between obesity and eating more meals late in the day, but that doesn’t mean eating at night causes obesity, the doctors point out. Eating more at any time of day will cause weight gain if it results in ingesting more calories than you need.

6. Hangovers can be cured.

The researchers found no scientific evidence supporting any type of cure for alcohol hangovers. Because hangovers are caused by drinking too much alcohol, the only way to avoid one is to drink very little or not at all.

Next year, the doctors plan to provide more research on medical myths in their new book, “Don’t Swallow Your Gum: Myths, Half-Truths, and Outright Lies About Your Body and Health,” to be published by St. Martin’s Press.

medical, myth, health