The study, being published in the June 26, 2006 issue of Archives of Internal Medicine, shows postmenopausal women who daily consume more than six cups of coffee, particularly decaffeinated, have a 33 percent lower risk of developing type 2 diabetes than women who do not drink coffee.
Researchers examined coffee intake and diabetes risk in 28,812 postmenopausal women who did not have type 2 diabetes or cardiovascular disease as part of the Iowa Women's Health Study (1986-1997). Over the 11-year period, 1,418 women reported being newly diagnosed with the illness.
"The risk reduction associated with coffee is independent of factors such as weight and physical activity," said Mark Pereira, Ph.D., lead author and associate professor at the University of Minnesota School of Public Health. "There appears to be great potential for coffee to help reduce the risk of diabetes. Identifying the mechanism responsible for this should definitely be the subject of further research."
Coffee is known to contain minerals and antioxidants that may aid in carbohydrate metabolism and insulin sensitivity and possibly delay the onset of type 2 diabetes. Overall caffeine intake did not appear to be related to diabetes risk in this study, further suggesting that another ingredient was responsible for the reduction.
Over 20 million Americans have diabetes, with 6.2 million of those cases being undiagnosed. People who have the illness either do not produce enough insulin for the body to process sugar or their cells ignore the insulin that is produced.
"Having a healthy diet, controlling your weight, and exercising are essential to preventing the onset of diabetes, but drinking coffee has the potential to further reduce risk of diabetes," said Pereira. "It may be necessary to rethink the idea that drinking coffee does more harm than good."
Higher coffee intake was also associated with lower body mass index (BMI) and rates of hypertension, as well as increased rates of alcohol consumption and smoking. Women who drank more coffee also ate less fruit and low-fat dairy products.
This research was supported by the National Cancer Institute.