Consuming five or more servings of dark chocolate per week was associated with a 21% lower risk of developing type 2 diabetes, with stronger associations observed among younger participants, males, and those with higher diet quality scores, while milk chocolate showed no similar benefit, according to a recent study.
Researchers examined the association between chocolate consumption and type 2 diabetes (T2D) risk. Using data from the Nurses’ Health Study (NHS), NHS II, and the Health Professionals Follow-Up Study, the team conducted a prospective analysis to evaluate total, dark, and milk chocolate intake in relation to incident T2D.
The study, published in The BMJ, included 192,208 patients without T2D, cardiovascular disease, or cancer at baseline. Chocolate consumption was assessed every four years using validated food frequency questionnaires, and T2D diagnoses were confirmed via supplementary questionnaires based on American Diabetes Association criteria. Cox proportional hazards regression models were employed to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).
Over 4,829,175 person-years of follow-up, 18,862 cases of incident T2D were identified. Patients consuming at least 5 servings of total chocolate per week had a 10% lower risk of T2D (95% CI 2% to 17%; p-trend=0.07) compared with those who rarely or never consumed chocolate. When stratified by chocolate subtype, dark chocolate consumption of at least 5 servings per week was associated with a 21% lower T2D risk (5% to 34%; p-trend=0.006). A dose-response relationship was observed, with each weekly serving of dark chocolate reducing T2D risk by 3% (95% CI 1%-5%; p-linearity=0.003). In contrast, no significant associations were found for milk chocolate consumption (HR 0.94, 95% CI 0.79-1.12; p-trend=0.75).
Further analysis revealed that increased milk chocolate intake was positively associated with long-term weight gain (+0.35 kg per four-year interval, 95% CI 0.27-0.43), while dark chocolate showed no significant weight impact (−0.06 kg, 95% CI −0.13 to 0.02). Stratified analyses indicated stronger inverse associations with dark chocolate intake among patients younger than 70 years, males, and those with higher diet quality scores. The study also found variability across cohorts, with stronger associations observed in some groups, such as younger individuals and males, but not uniformly across all participants.
The researchers noted that dark chocolate, rich in flavanols, was associated with a lower risk of T2D, suggesting potential protective effects; however, they emphasized that causation was not established and called for randomized controlled trials to confirm these findings and explore underlying mechanisms.
Full disclosures can be found in the published study.
