Coffee, tea, or diabetes? Drinking three to four cups of coffee or tea daily reduces the risk of type 2 diabetes mellitus, according to a pooled review of 20 studies covering about half a million people. An international team of researchers found that drinking three to four cups of caffeinated coffee daily lowered diabetes risk by 25%, compared with drinking zero to two cups. People who drank three to four cups of decaffeinated coffee or tea also had a lower diabetes risk. "The identification of the active components of these beverages would open up new therapeutic pathways for the primary prevention of [type 2 diabetes]," the authors write in the December 2009 Archives of Internal Medicine.