Medical myths - II

MJ  2007;335:1288-1289 (22 December), doi:10.1136/bmj.39420.420370.25

Mixed messages

Medical myths

Rachel C Vreeman, fellow in children’s health services research¹, Aaron E Carroll, assistant professor of paediatrics²

¹ Children’s Health Services Research, Indiana University School of Medicine, Indianapolis, IN, USA, ² Regenstrief Institute, Indianapolis, IN, USA

Correspondence to:R C Vreeman rvreeman@iupui.edu

Sometimes even doctors are duped, say Rachel C Vreeman and Aaron E Carroll

Physicians understand that practicing good medicine requires the constant acquisition of new knowledge, though they often assume their existing medical beliefs do not need re-examination. These medical myths are a light hearted reminder that we can be wrong and need to question what other falsehoods we unwittingly propagate as we practice medicine. We generated a list of common medical or medicine related beliefs espoused by physicians and the general public, based on statements we had heard endorsed on multiple occasions and thought were true or might be true. We selected seven for critical review:

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

We used Medline and Google to search for evidence to support or refute each of these claims. Because "proving a negative" can be challenging, we noted instances in which there was no evidence to support the claim.