Eat Dark Chocolate to Lower the Risk of Type 2 Diabetes: Study Suggests

The researchers used data from the Nurses’ Health Studies I and II and the Health Professionals Follow-up Study. Over 30+ years, 192,000 adult participants who were free of diabetes at the study’s outset reported on their food habits, including chocolate consumption, as well as their diabetes status and body weight. By the end of the study period, nearly 19,000 of the total participants reported being diagnosed with T2D. Of the nearly 112,000 who reported specifically on their dark and milk chocolate intake, nearly 5,000 were diagnosed with T2D.

Key points from the study are:

Study participants who consumed at least five servings of any chocolate per week showed a 10% lower risk of type 2 diabetes (T2D) compared to those who rarely or never ate chocolate. Dark chocolate had an even bigger impact: Participants who consumed at least five servings of this chocolate per week showed a 21% lower risk of T2D.

Consumption of milk chocolate, but not dark chocolate, was not associated with T2D risk; it was associated with excessive long term weight gain, a potential contributor to the development of T2D.

According to the researchers, opting for dark chocolate rather than milk chocolate can make a big difference for health. They also noted that average chocolate consumption among study participants was relatively low, so the findings may not extrapolate to people with very high levels of consumption.

“We were surprised by the clear split between dark and milk chocolate’s impact on diabetes risk and long-term weight management,” said corresponding author Qi Sun, associate professor in the Departments of Nutrition and Epidemiology. “Even though dark and milk chocolate have similar levels of calories and saturated fat, it appears that the rich polyphenols in dark chocolate might offset the effects of saturated fat and sugar on weight gain and diabetes. It’s an intriguing difference that’s worth exploring more.”

Reference: “Chocolate intake and risk of type 2 diabetes: prospective cohort studies,” Binkai Liu, Geng Zong, Lu Zhu, Yang Hu, JoAnn E. Manson, Molin Wang, Eric B. Rimm, Frank B. Hu, Qi Sun, The BMJ, published online December 4, 2024, doi: 10.1136/bmj-2023-078386