But the question remains, why does coffee seem to lower diabetes risk? Is it the caffeine?
Researchers from Harvard wanted to know the answer. They conducted a meta-analysis of 28 prospective studies of coffee with 1,109,272 participants. Follow-up ranged from 10 months to 20 years.
Their results published in the American Diabetes Association journal Diabetes Care confirmed that drinking coffee was inversely associated with the risk of type 2 diabetes. And it's dose dependent. The more you drink, the lower the risk. For one cup a day the relative risk dropped to 92%; for three cups a day, to 79%; and for six cups a day it dropped to 67%.
But the researchers also concluded that it doesn't matter whether your coffee is decaf or high test. You get the benefits either way. That seems to indicate that it's not caffeine's impact on insulin levels that makes the difference. Instead, the researchers suggested that other compounds in coffee like polyphenols may be responsible for coffee's health benefits.
The results are consistent with an earlier prospective cohort study from Harvard researchers that included 88,259 U.S. women from the Nurses' Health Study II. That study concluded that very high consumption was not required to realize coffee's health benefits. Their results suggested that drinking just two or more cups per day was associated with a lower diabetes risk.
Other research indicates drinking coffee kills pain, lifts mood, and sharpens the mind. Drinking decaf coffee may help reduce diabetes risk and bestow additional health benefits while avoiding some of the potential adverse effects of caffeine like the jitters and inability to sleep.
Caffeine is a form of natural pest control protecting the coffee plant from bugs with its bitter taste. A typical cup of regular coffee contains about 100 milligrams of caffeine.
You probably know by now that even coffee advertised as decaf contains caffeine. The general rule of thumb is that the decaffeination process removes from 94 to 99% of the caffeine. So you should expect your cup of decaf to provide one to six milligrams of caffeine per cup.
Although coffee is considered a psychoactive drug, it is not regulated by the U.S. Food and Drug Administration. There's currently no requirement to disclose caffeine amounts in coffee or other products.
Coffee labeled or sold as "decaffeinated" may contain anywhere between 2 and 13 milligrams of caffeine. A tall decaf Starbucks can have up to 20 milligrams. So if you are particularly sensitive, beware.
For more information on coffee's health benefits, visit GreenMedInfo's coffee page.