06 February, 2008

Urban legends

The end-of-year BMJ is a light-hearted issue which allows us to raise our eyes above the temperature charts and dwell on the funny side of our profession. Vreeman & Carroll (BMJ 2007;335:1288-9) bust a few medical myths that we may have wondered about:

Drink 8 glasses of water a day - not necessary. There is far more fluid in our food than we realise and our thirst signals when more is needed.

We use 10% of our brains - no areas of our brains are inactive for long despite many functions being localised.

Hair and fingernails grow after death - untrue but skin retraction from desiccation can give that appearance.

Reading in dim light ruins your eyes - poor lighting may make restaurant menus difficult to read but by next morning your eyes will be fine.

Shaving makes hair grow faster - shaving your chin or your legs removes the dead part of the hair and does not encourage growth.

Mobile phones are dangerous in hospitals - no serious consequences of mobile (cellular) phone use in hospitals have been reported and certainly no deaths.
Conversely, the use of mobile phones reduces errors from delays in communication.

Eating turkey makes you drowsy - turkey contains no specific sedatives but usually forms part of a large meal, redirecting blood flow from the brain to the abdomen, causing drowsiness.