23 December 2007

Know That These are Medical Myths!

The Christmas edition of the BMJ has one pretty interesting article I think both doctors and patients should be informed about. The authors selected 7 of the most common medical myths propagated throughout the years. They caution that "sometimes even doctors are duped," and if that is the case, their patients are equally duped. So guys, here they are:

There is no study or evidence that supports this advice. Our daily fluid requirement can be met not only by drinking water but in consuming other forms of liquid like juices, soup, coffee, and tea, as well as eating fruits which also have some degree of water content in them. Unknown to many, drinking too much water can result in water intoxication, low sodium levels, and can be even be fatal.

Even your parents might have admonished you to stop reading in low light, and you listened, afraid that you might get more scolding. Well, guess what? While it is true that reading in dim light strains your eyes because of increased efforts to focus, it is not true that doing so will result in permanent eye damage or that you will go blind. As the article concluded, "hundreds of online expert opinions conclude that reading in low light does not hurt your eyes."

The article says that review of literature disproves this claim. No study or investigation has found the "non-functioning 10 percent," and several brain imaging studies have shown that "no area of the brain is completely silent or inactive."

Shaving has no effect on the quality of hair growth. The article explains that when one shaves, only the dead portion of the hair is removed, and none of the living part of the reproducing skin, and therefore, "it is unlikely to affect the rate or type of growth."

No such thing happens. Just plain optical illusion. The article cites dermatologists' explanation that dehydration after death might account for this. "The skin’s retraction can create an appearance of increased length or of greater prominence because of the optical illusion created by contrasting the shrunken soft tissues with the nails or hair."

Little evidence supports this claim, and most are purely anecdotal. There is a study mentioned that showing that mobile phones interfered with only 4 percent of hospital devices at a distance of less than 1 meter, with only 0.1 percent exhibiting serious effects. A more recent 2007 study showed "no interference of any kind during 300 tests in 75 treatment rooms."

This will have little impact in the Philippines since people here still prefer chicken over turkey. Does eating chicken produce the same effect? I have been eating chicken for a long time, and I have not particularly noticed being extra sleepy after finishing a meal of fried chicken. Both chicken and minced beef contain nearly equivalent amounts of tryptophan --- about 350mg/115grams of turkey serving. The claim asserts that since turkey contains tryptophan (which is known to cause drowsiness), eating it makes one sleepy. The truth is that turkey does not contain significant amounts of tryptophan to cause a sleepy feeling. Sleepiness after any meal might be because of normal physiological processes in which blood flow and oxygenation to the brain decreases because of nutrient transport during the food digestion process.

Lastly, the authors offer sound advice to all doctors:
Physicians would do well to understand the evidence supporting their medical decision making. They should at least recognise when their practice is based on tradition, anecdote, or art. While belief in the described myths is unlikely to cause harm, recommending medical treatment for which there is little evidence certainly can. Speaking from a position of authority, as physicians do, requires constant evaluation of the validity of our knowledge.

5 reactions:

rolly said...

Doc, what about not sleeping when the hair is wet? Masama yun diba?

Kasi mababasa unan - di ka makakatulog!

Merry Christmas to you and soulmate!

Bone MD said...

and so does drinking cold water induces cough and colds...myths we rarely dispute...nice post doc

ipanema said...

Oh my, I grew up believing in those as well. lol@ Rolly. :)

Anyway, a blessed and joyous Christmas to you and yours!

bayi said...

Well, there goes some of the beliefs that have been drummed into us since time memorial. Surprisingly, similar false beliefs are perpetuated in all the races. I have always thought that I wear glasses because of my interest in reading, even in dim light.

Merry Christmas, Dr Emer and Jane!

may said...

merry christmas doctor emer! are you back from your fancy holiday yet? i'm sure you had fun :)