Friday June 26, 2015 (foodconsumer.org) -- Dark chocolate is known to be heart healthy. A new study recently published in the American Journal of Clinical Nutrition now suggests that chocolate consumption may also help reduce risk of diabetes mellitus. 

The study led by Chisa Matsumoto from Tokyo Medical University in Tokyo, Japan and colleagues revealed an inverse association of chocolate intake with the risk for type 2 diabetes mellitus.

The data used in the study came from 18,235 participants in the Physicians' Health Study, who were free of diabetes mellitus at baseline and enrolled in the study between 1997 and 2001.  Chocolate consumption was estimated based on the information obtained through a baseline food frequency questionnaire.  Participants at the mean age of 66.3 years at baseline were followed up for a mean 9.2 years.
 
Researchers found that compared to those who did not eat any chocolate, those who ate 1 to 3 servings per month, 4 servings per month, or 8 or more servings per month were at 7%, 14% or 17% reduced risk for diabetes mellitus, respectively,  after adjustment for lifestyle, clinical and dietary risk factors.

Among participants who did not have cardiovascular disease or heart failure, the inverse association was even stronger.  Also, both age and body mass index modified the association of chocolate and diabetes mellitus.

The researchers concluded "Our data support an inverse relation of chocolate intake with incident DM, which appears only to apply in younger and normal–body weight men after controlling for comprehensive life styles including total energy consumption."

Previous studies found evidence suggesting that cocoa or chocolate may protect against insulin resistance, oxidative stress, and inflammation, which are risk factors for type 2 diabetes mellitus. But the current study directly associated chocolate intake with the reduced risk for diabetes mellitus.

There are two major types of chocolate, milk chocolate and dark chocolate.  Some studies suggest that dark chocolate helps heart health due probably to the presence of cocoa in the food.  It is possible that cocoa in dark chocolate also protect against diabetes mellitus. 

The study did not tell what type of chocolate is beneficial or more beneficial. But if these two types of chocolate were separated and studied, one may find that the dark chocolate may be more "effective" than what this study revealed at preventing diabetes mellitus while milk chocolate may be less beneficial if there is any. (David Liu)

Chisa Matsumoto, Andrew B Petrone, Howard D Sesso, J Michael Gaziano, and Luc Djoussé , Chocolate consumption and risk of diabetes mellitus in the Physicians’ Health Study, The American Journal of Clinical Nutrition, 2015