CATEGORY: METABOLIC & BLOOD SUGAR
People who ate at least five servings of dark chocolate a week had a 21% lower risk of developing type 2 diabetes—a condition in which the body struggles to keep blood sugar (glucose) at healthy levels—than those who rarely or never ate it, according to a large analysis of three long-running studies of US health professionals.1
How the Study Worked
Researchers followed 192,208 people who were free of diabetes, heart disease, and cancer at the start, drawing on the Nurses’ Health Study, its follow-up, and the Health Professionals Follow-Up Study. Participants reported how often they ate chocolate on repeated food questionnaires, and new cases of type 2 diabetes were identified through follow-up surveys and confirmed with a validated questionnaire. Over more than 4.8 million combined person-years of follow-up, 18,862 people developed the condition. A smaller group of 111,654 participants reported dark and milk chocolate separately, which let the team compare the two.
Dark and Milk Chocolate Differed
Eating any type of chocolate five or more times a week was linked to a 10% lower rate of type 2 diabetes, but the pattern was strongest for dark chocolate, which is richer in cocoa flavanols—plant compounds thought to influence how the body handles sugar. Each additional weekly serving of dark chocolate was associated with a 3% lower risk. Milk chocolate showed no such link, and higher milk chocolate intake was instead associated with long-term weight gain.
What the Findings Do and Don’t Show
Because this was an observational study, it can show an association between dark chocolate and lower diabetes risk but cannot prove the chocolate itself is responsible; other habits of dark chocolate eaters may play a role. The researchers noted that randomized trials are still needed to confirm the effect. If you are wondering how your own eating patterns relate to your blood sugar, that is a conversation to have with your health care provider.
Key Takeaways
- In three large cohorts, eating dark chocolate at least five times a week was associated with a 21% lower risk of type 2 diabetes.
- Milk chocolate showed no similar benefit and was linked to weight gain over time.
- This is an association, not proof of cause; your provider can help you understand your personal diabetes risk.
References
- Liu B, Zong G, Zhu L, et al. Chocolate intake and risk of type 2 diabetes: prospective cohort studies. BMJ. 2024;387:e078386. link.