MONDAY, Jan. 5, 2004 (HealthDayNews) -- People who tank up on coffee may reduce their risk of developing type 2 diabetes, new research suggests.
The study of more than 126,000 men and women found people who drank more full-test coffee had a lower risk of the blood sugar disease than those who drank less or none of the beverage. The effect was greatest for men whose coffee intake topped five cups a day. This group had about half the odds of developing diabetes as men who didn't drink any regular coffee.
Women who drank caffeinated coffee also gained protection from type 2 diabetes, though not quite as much as men. For both men and women, the effects of coffee drinking on diabetes risk didn't become pronounced until people downed at least four cups a day.
The average coffee drinker in the United States consumes about three cups a day, according to the Coffee Research Institute. In the latest study, in which Harvard University researchers combined data from two large, previous studies, average coffee consumption was about one to two cups a day.
However, the researchers warn their study "cannot prove a cause-effect relationship" between caffeine consumption and a lower risk of diabetes. And, they add, "it is premature to recommend increased coffee drinking as a means to prevent type 2 diabetes."
The latest work, reported in the Jan. 6 issue of the Annals of Internal Medicine, is one of several studies linking coffee to healthier blood sugar. A separate report this month also found Swedish women who drank several cups of coffee a day were less likely to have diabetes than those who consumed less of the beverage.
While coffee's ability to lower the risk of diabetes has come up in several studies, how it does so isn't clear. "Coffee contains several hundreds, if not thousands, of different compounds," says Dr. Annika Rosengren, a cardiologist at Sahlgrenska University Hospital in Goteborg, Sweden, who led the coffee study from that country. "It's very difficult to say which compound is the protective one."
What's more, in the short run coffee seems to impair, not improve, the body's sensitivity to insulin, the hormone that helps cells take up blood sugar.
People who drink lots of coffee often have other unhealthy habits, including smoking, drinking alcohol and leading a sedentary lifestyle. But the researchers found coffee consumption reduced the risk of diabetes even after accounting for these factors.
Although the study didn't find a statistically significant link between tea and protection from diabetes, the results did suggest such an effect might exist.
More information
For more on diabetes, visit the National Institute of Diabetes and Digestive and Kidney Diseases. For more on coffee, try the Coffee Research Institute.
