A recent study from Harvard T.H. Chan School of Public Health suggests that consuming dark chocolate, rather than milk chocolate, may lower the risk of developing type 2 diabetes (T2D).
According to Binkai Liu, the study’s lead author and a nutrition doctoral student, “Our findings indicate that not all chocolates are the same. For chocolate enthusiasts, it’s a reminder that small choices, like opting for dark chocolate instead of milk chocolate, can lead to health benefits.”
This research is set to be published on December 4 in The BMJ.
While previous studies have explored the link between chocolate and T2D, results have varied, and few have distinguished between types of chocolate, particularly dark versus milk.
To address this, researchers utilized data from the Nurses’ Health Studies I and II and the Health Professionals Follow-up Study. Over more than 30 years, 192,000 adults without diabetes at the start reported their dietary habits, including chocolate intake, as well as updates on their diabetes status and body weight. By the end of the study period, nearly 19,000 participants were diagnosed with T2D, and out of about 112,000 who shared details about their dark and milk chocolate consumption, nearly 5,000 were diagnosed with the condition.
The results revealed that those consuming at least five ounces of chocolate each week had a 10% reduced risk of developing T2D compared to those who rarely or never indulged. Specifically, individuals who ate at least five servings of dark chocolate weekly experienced a 21% lower risk. The risk decreased by 3% for each additional serving of dark chocolate consumed weekly, while milk chocolate showed no association with reduced T2D risk. Interestingly, higher intake of milk chocolate correlated with long-term weight gain, which can contribute to the onset of T2D.
Qi Sun, an associate professor in Nutrition and Epidemiology and the study’s corresponding author, stated, “We were taken aback by the distinct differences in how dark and milk chocolate affect diabetes risk and long-term weight control. Despite dark and milk chocolates having similar calorie and saturated fat content, the abundant polyphenols found in dark chocolate might mitigate the adverse effects of saturated fat and sugar on diabetes and weight gain. This intriguing distinction warrants further investigation.”
The researchers pointed out that the participants’ chocolate intake was relatively low compared to previous national averages, suggesting that the results may not be applicable to those with high chocolate consumption.
Other contributors from Harvard Chan to the study included Lu Zhu, Yang Hu, JoAnn Manson, Molin Wang, Eric Rimm, and Frank Hu.
Funding for the study came from the National Institutes of Health, with various grant numbers including UM1 CA186107, P01 CA87969, R01 HL034594, U01 CA176726, U01 CA167552, R01 HL035464, R01 HL60712, R01 DK120870, R01 DK126698, R01 DK119268, U2C DK129670, R01 ES022981, and R21 AG070375.
