An 11-years study on more than 28000 postmenopausal women in Iowa proved that decaf coffee consumers develop lower risks of getting ill with type 2 diabetes. Of the women tested, the ones that drank 6 cups of decaf coffee a day proved to have 22% chances of keeping diabetes away than the women that drank regular coffee or not at all. Even most amazingly, the women that drank more than 6 cups of decaf coffee daily were 33% less likely to develop type 2 diabetes.

The cause of this beneficial effect is not known for sure, but it seems to be related to the fact that substances in the decaf coffee have a positive role in body's regulation of sugar. This could be the more valid explanation, as type 2 diabetes patients no longer break down sugar properly.

Consequently, it is not the caffeine, but the antioxidants in the coffee that help people keep healthy: epidemiologist Mark Pereira at the University of Minnesota and his colleagues who led the study found a possible root of the effect in antioxidants' ability to protect the cells in the pancreas that produce insulin, the hormone that helps the body regulating the sugar.

In this respect, Pereira said: "There are quite a lot of people in our population who drink high amounts of coffee, and that's not true with other sources of antioxidants like fruits and grains and vegetables. But it would be premature to make any public-health recommendations based on current research alone."