7 Medical Myths

British Medical Journal: Medical myths

Excerpt:

People should drink at least eight glasses of water a day

The advice to drink at least eight glasses of water a day can be found throughout the popular press.w1-w4 One origin may be a 1945 recommendation that stated: A suitable allowance of water for adults is 2.5 litres daily in most instances. An ordinary standard for diverse persons is 1 millilitre for each calorie of food. Most of this quantity is contained in prepared foods. If the last, crucial sentence is ignored, the statement could be interpreted as instruction to drink eight glasses of water a day.

Another endorsement may have come from a prominent nutritionist, Frederick Stare, who once recommended, without references, the consumption "around 6 to 8 glasses per 24 hours," which could be "in the form of coffee, tea, milk, soft drinks, beer, etc." The complete lack of evidence supporting the recommendation to drink six to eight glasses of water a day is exhaustively catalogued in an invited review by Heinz Valtin in the American Journal of Physiology. Furthermore, existing studies suggest that adequate fluid intake is usually met through typical daily consumption of juice, milk, and even caffeinated drinks. In contrast, drinking excess amounts of water can be dangerous, resulting in water intoxication, hyponatraemia, and even death.


The List:

1. People should drink at least eight glasses of water a day
   
2. We use only 10% of our brains
   
3. Hair and fingernails continue to grow after death
   
4. Shaving hair causes it to grow back faster, darker, or coarser
   
5. Reading in dim light ruins your eyesight
   
6. Eating turkey makes people especially drowsy
   
7. Mobile phones create considerable electromagnetic interference in hospitals.
   
   

Comment: I had my own encounter with medical myth # 1 this year. I saw a throat specialist and then visited a speech therapist twice (I was hoarse). The speech therapist said I should drink my weight ÷ 2 ounces of fluid a day. I weigh 235 so that would be 117 oz a day. The speech therapist told me that juice, milk, diet soda, and coffee did not count. It had to be 117 oz of water! I take a large thermos (32 oz) of water to work every day. One day I tried to drink that times 2. 64 oz is a lot of water! I never made it to the 117 oz!

As for medical myth # 4, my bald pate is proof of this myth!