Does supplementing with cocoa extract reduce the risk of type 2 diabetes? Original paper

In this randomized controlled trial in older adults, supplementing with cocoa extract did not reduce the risk of developing type 2 diabetes.

Whether supplementing with cocoa extract reduces the risk of developing type 2 diabetes (T2D).

18,381 participants (average age of 72; 59% women, 41% men), 801 of whom developed T2D during the study.

This study was a secondary analysis of the COSMOS randomized controlled trial,^[1] which involved 4 groups and examined the effects of supplementing with cocoa extract, a multivitamin, or their combination on chronic disease risk.

The summarized study combined the data from the groups that supplemented with cocoa extract and combined the data from the groups that did not supplement with cocoa extract (i.e., they either supplemented with a multivitamin and a placebo or 2 placebos) and compared the differences in T2D risk between these two groups.

The cocoa extract supplement provided 500 milligrams of cocoa flavonols, and the supplement was taken daily over a median follow-up period of 3.5 years. The results were adjusted for potential confounders, including sociodemographic factors, smoking, physical activity, BMI, diet quality, and family history of diabetes.

Compared to placebo, cocoa extract did not affect T2D risk.

Although the original trial was statistically powered to detect a reduction in the risk of cardiovascular disease, the incidence rate for T2D was higher than for cardiovascular disease. Therefore, although T2D risk was a secondary outcome, it’s likely that there was adequate statistical power in this study to detect differences in T2D risk between groups.