Last updated: May 22, 2009
You think youll ruin your eyesight by reading in low light, right? Thats a myth, according to Indiana University pediatric MDs Aaron Carroll and Rachel Vreeman. Their new book, Dont Swallow Your Gum! Myths, Half-Truths, and Outright Lies About Your Body and Health (St. Martins Griffin, 2009; $14), takes on a ton of whoppers, including these biggies:


1. You only use 10% of your brain. Actually, modern imaging techniques show that no area of the brain is inactive—you use 100%!

2. Fluoride in water is dangerous. Major medical groups say fluoridated water helps prevent cavities, and the Centers for Disease Control and Prevention even says the addition of fluoride to water is one of the 10 biggest health achievements of the 20th century. At one time it was thought that fluoridated water might harm the brain or bones, but thats just not true.

3. After menopause, you lose all interest in sex. Menopausal symptoms may make sex less enjoyable, which could affect your desire, but only 30% of women in their 50s report not having sex.

4. Garlic repels mosquitoes. Sorry, it may repel people you dont like, but not bugs. For long-lasting protection, stick with repellents that have DEET or Picaridin.