Health myths: Exposed!

Lyssa Beyer

Shaving hair causes it to grow back faster, darker or coarser.

Myth. This common belief is often repeated in the media and reinforced when coarse stubble appears on the body after shaving. A 1928 clinical trial showed that shaving had no effect on hair growth, a finding confirmed by more recent studies. When hair grows back after shaving, it seems coarse because it doesn’t have the fine taper of unshaved hair. It seems darker because it hasn’t been exposed to the sun like the previously unshaved hair.

Reading in dim light ruins your eyesight.

Myth. The idea that dim light ruins eyesight probably has its origins in eye strain. Bad lighting makes it hard to focus, makes you blink less and leads to dry eyes, particularly if you’re squinting. So reading in dim light is uncomfortable, but it doesn’t cause permanent damage.

Eating turkey makes people especially drowsy.

Myth. This one stems from the fact that turkey contains tryptophan, an amino acid found in proteins and essential to the human body. Scientific studies show that sleep and mood are affected by tryptophan.

However, turkey does not contain an exceptional amount of tryptophan. Chicken and beef contain about the same amount, and pork and cheese contain more tryptophan per gram than turkey. Because turkey is consumed with other foods, absorption of tryptophan from turkey is minimal, noted the authors. The myth likely stems from the fact that everyone feels drowsy after eating a large meal because the body is using energy to digest food and blood flow and oxygenation to the brain decreases.

Cellphones create considerable electromagnetic interference in hospitals.

Myth. Anecdotal reports persist that cellphones create false alarms on monitors and malfunctions in infusion pumps. After publication of a medical journal article citing more than 100 reports of suspected electromagnetic interference with medical devices before 1993, The Wall Street Journal published a front page article on the topic. As a result, many hospitals banned the use of cellphones, perpetuating the belief.

But study authors found no evidence to support it. At the Mayo Clinic in 2005, in 510 tests performed with 16 medical devices and six mobile phones, the incidence of clinically important interference was 1.2 percent. A 2007 study that examined cellphones “used in a normal way” found no interference of any kind during 300 tests in 75 treatment rooms.

-Source: The New York Times

Health Myths Exposed! is a bi-weekly feature highlighting common health and fitness misconceptions compiled by Money/Health editor Tara Bannow.