Mice that were fed cocoa with a high-fat diet experienced less obesity-related inflammation than mice fed the same high-fat diet without the supplement, Joshua Lambert, associate professor of food science, said.
The mice ate the human equivalent of 10 tablespoons of cocoa powder-about four or five cups of hot cocoa-during a 10-week period.
"What surprised me was the magnitude of the effect. There wasn't as big of an effect on the body weight as we expected, but I was surprised at the dramatic reduction of inflammation and fatty liver disease," Lambert said.
The researchers reported that several indicators of inflammation and diabetes in the mice that were fed the cocoa supplement were much lower than the mice that were fed the high-fat diet without the cocoa powder and almost identical to the ones found that were fed a low-fat diet in the control group.
For example, they had about 27 percent lower plasma insulin levels than the mice that were not fed cocoa. High levels of insulin can signal that a patient has diabetes.
The cocoa powder supplement also reduced the levels of liver triglycerides in mice by a little more than 32 percent, according to Lambert, who worked with Yeyi Gu, graduate student in food science, and Shan Yu, a graduate student in physiology. Elevated triglyceride levels are a sign of fatty liver disease and are related to inflammation and diabetes.
The mice also saw a slight but significant drop in the rate of body weight gain, according to the researchers.
The findings are published online in the European Journal of Nutrition.