Seven Medical Myths

An interesting article appeared in the December 22, 2007 issue of the British Medical Journal. In that article, the authors, Rachel C Vreeman, fellow in children's health services research of the Indiana University School of Medicine, and Aaron E Carroll, assistant professor of pediatrics Regenstrief Institute, Indianapolis, Indiana, tackled the seven most common medical myths.

The authors researched each of these common myths and reported on them in the BMJ article. The synopsis of their findings is listed below.

1) People should drink at least eight glasses of water a day
The researchers noted that the 8 glass number is seen in many places in the popular press. However, they found that this number actually came from recommendations first put forth in 1945. In those original recommendations it was suggested that adults should have 1 milliliter of water for each calorie of food, which equates to about 2.5 liters daily or about 8 glasses of water. However, the researchers note that one important sentence in the original recommendations is commonly overlooked. That sentence reads. "Most of this quantity is contained in prepared foods." With this discovery and other information they uncovered the article notes, "studies suggest that adequate fluid intake is usually met through typical daily consumption of juice, milk, and even caffeinated drinks."

2) We use only 10% of our brains
The authors found that this myth goes back as far as 1907. This myth probably had more to do with the desire for self improvement than the actual amount of the brain being used. The authors note that this myth is totally false and there are no unused or dormant parts of the brain.

3) Hair and fingernails continue to grow after death
Again this is untrue. The authors note that dehydration of the body after death may lead to skin retraction which may make the hair and fingernails appear to be more pronounced and therefore look like they have grown.

4) Shaving hair causes it to grow back faster, darker, or coarser
The authors state that this myth continues to be carried by popular media. However, they note that this myth has been scientifically disproved in multiple studies dating back as far as 1928. They clearly state, "recent studies confirm that shaving does not affect the thickness or rate of hair regrowth."

5) Reading in dim light ruins your eyesight
The authors note that reading in dim light can create eye strain and decreases the rate of blinking which can lead to discomfort. However, they note that none of these symptoms persist. After consulting many experts, the authors conclude, "reading in low light does not hurt your eyes."

6) Eating turkey makes people especially drowsy
The authors note that this myth is based on the fact that turkey contains tryptophan, which does contribute to sleepiness. However, they note that turkey contains no more tryptophan than chicken or ground beef. They explain that the sleepiness is more likely related to the volume of food consumed when turkey is eaten as a holiday meal.

7) Mobile phones create considerable electromagnetic interference in hospitals
This may be the only myth that could be true. Although the researchers could find no scientific evidence to support this myth, there have been a few reported cases of equipment malfunction in hospitals that could be attributed to cell phones. As a result, and probably precautionary, many hospital have banned cell phones in critical areas.