These seven myths have worked their way into “common knowledge,” but none of them are supported by evidence:

• 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.