Researchers compared the coffee consumption habits of 28,812 women enrolled in the Iowa Women's Health Study and found that the women who drank the most coffee -- especially decaffeinated varieties -- were 22 percent less likely to develop diabetes than women who didn't consume coffee.
When the study began in 1986, none of the participants had diabetes. During follow-up tests, 1,418 of the women were found to have the disorder. The data also showed that decaffeinated coffee provided the greatest benefits. The connection was seen in all age and weight groups.
Researchers don't know which ingredients in coffee provide the protective benefit; although it is known that caffeine does not reduce diabetes risk. Two other components of coffee, magnesium and phytate, do not appear to affect risk either.
While coffee may help lower risk, experts agree that proper diet and exercise is still the first defense against metabolic disorders, including diabetes. Additionally, even though coffee itself may offer some protection against diabetes, caffeine is known to cause adrenal depletion and chronic exhaustion if consumed daily.
Ingredients commonly used in coffee drinks pose additional health hazards. Coffee creamer, typically made with partially-hydrogenated oil, may boost the risk of cardiovascular disease and promote gains in abdominal fat. Similarly, adding refined sugar to coffee actually promotes blood sugar disorders, possible nullifying any protective effect against diabetes. A typical Starbucks grande coffee (16 oz.) has a whopping 550mg of caffeine and can be juiced up with so much fat and sugar that it's more like a milkshake than coffee.