When Doctors Don’t Know the Best Medical Advice

Doctors help bodies heal and stay healthy, but they’re still human. So your physician might not have gotten every memo on the latest findings from health research done in the past few years. As a result, some of her recommendations may be out-of-date, unhelpful, or even harmful. Case in point: Although research has proved that cloudy mucus often isn’t a sign of a bacterial infection, physicians are six times as likely to prescribe antibiotics to patients whose nasal discharge has a greenish tint compared with those whose discharge is clear.

We’ve combed through the most recent research and consulted experts on the latest thinking in nutrition, fitness, sleep, back pain, and more. Read on to learn what long-standing advice you should trash—and the smarter, science-backed tips you should replace it with.

Old Medical Advice: Many dentists advise their patients to scrub away cavity-causing plaque as soon as possible. Nine in ten Americans believe that it’s important to brush immediately after each meal, according to an American Dental Association survey.

New Medical Advice: Rinse your mouth with water immediately after eating, but wait 30 minutes before you brush. Making a beeline for the sink may harm your teeth by rubbing in acids from foods and beverages such as citrus fruit, vinegar, and soda. This could wear down the tooth enamel and underlying dentin. “Similar to scrubbing detergent into a pan, brushing can rub in acid and lead to damage,” says Steven Ghareeb, DDS, a spokesperson for the Academy of General Dentistry and a dentist based in Charleston, West Virginia.

Next: When do you really need antibiotics? »