Dark Chocolate Could Reduce Your Risk of Type 2 Diabetes, According to a New Harvard Study

It turns out your cheeky little chocolate habit may not be so naughty after all. 

In early December, researchers from Harvard published their study in the British Medical Journal, looking at the impacts of eating chocolate on your overall health. And, according to the conclusion, it’s great news for those who consume dark chocolate over anything else — especially if you’re trying to stave off Type 2 diabetes. 

“Our findings suggest that not all chocolate is created equal,” Binkai Liu, the lead author of the study and a doctoral student in the Department of Nutrition at Harvard, shared in a statement. “For anyone who loves chocolate, this is a reminder that making small choices, like choosing dark chocolate over milk chocolate, can make a positive difference to their health.”

The team found plenty of research on chocolate and its relationship to type 2 diabetes. However, they realized that very few of those studies separated chocolate subtypes, such as dark vs. milk chocolate. 

So, it sought to answer this very important candy question by using data from the Nurses’ Health Studies I and II and the Health Professionals Follow-up Study, which followed 192,000 adults for more than three decades who began the study as diabetes-free participants, and all self-reported their food habits, including chocolate. At the end of the study period, some 19,000 participants reported they received a Type 2 diabetes diagnosis over the years, while 112,000 people overall reported their dark and milk chocolate intake. Of those 112,000, the team found that 5,000 were diagnosed with Type 2 diabetes. 

According to the researchers, participants who consumed at least five ounces of any type of chocolate per week had a 10% lower risk of developing Type 2 diabetes compared to those who never or rarely consumed chocolate. However, here’s where things get interesting. Those who consumed at least five servings of dark chocolate per week showed a 21% lower risk of type 2 diabetes. The team even observed a 3% reduction in risk for every serving of dark chocolate consumed per week. Sadly for milk chocolate lovers, it didn’t show the same results (in fact, consumption of milk chocolate was associated with long-term weight gain, which is a major risk factor for Type 2 diabetes, the team explained). 

“We were surprised by the clear split between dark and milk chocolate’s impact on diabetes risk and long-term weight management,” Qi Sun, a corresponding author and associate professor in the Departments of Nutrition and Epidemiology, added. “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.”

Here’s the only caveat (because, of course, there is one): According to the researchers, the participants in this study reported lower-than-average chocolate consumption compared to national averages. This study also only shows a causal relationship between chocolate consumption and reduced risk; it cannot prove cause and effect.

Additionally, the authors added, “The findings may not apply to individuals with very high chocolate consumption,” so don’t go wild with your chocolate bars. But do nibble on them every now and then—you know, for health. Just make sure you’re getting the highest-quality chocolate before indulging.