Investigators followed 8,004 men from the island of Oahu over the course of 30 years. They interviewed the men in the 1960s and '70s about their diets, and then tracked who got Parkinson's disease, a neurodegenerative disorder that afflicts about 1 million Americans. After controlling for other factors, such as age and cigarette smoking, researchers found that men who drank at least 28 ounces a day were only one fifth as likely to get the disease, whether they took the beverage black or with cream and sugar. Chocolate, caffeinated tea, and cola also helped fend off Parkinson's. This single study, though, is not reason enough to make a beeline for the nearest latte bar.
Experts caution that the conclusion, drawn only from Japanese-American men, is preliminary.
If you're not a coffee drinker and suddenly you go out and drink four to six cups a day, you'll probably get more problems than benefits. Caffeine is not a benign substance, he says. It increases gastric acid, affects sleeping patterns, and makes ulcers bleed. Doctors are now pondering how a substance that makes people jittery could stave off a disease that causes tremors. One explanation is that caffeine protects against the nerve damage in the brain that leads to Parkinson's disease.