Chocolate consumption and risk of diabetes mellitus in the Physicians' Health Study.

Previous studies reported beneficial effects of cocoa or chocolate on insulin resistance, oxidative stress, and inflammation, which are important risk factors of type 2 diabetes mellitus (DM). However, it is unclear whether chocolate consumption is associated with risk of DM. We tested the hypothesis that chocolate consumption is inversely associated with incident DM in the Physicians' Health Study (PHS). We prospectively analyzed data on 18,235 PHS participants who were free of DM at baseline (1997-2001). Chocolate consumption was obtained from a baseline food-frequency questionnaire. Incident DM was ascertained via annual follow-up questionnaires and validated in a subsample by a review of medical records. We used Cox proportional hazards models to estimate HRs and 95% CIs of DM. The mean (±SD) age at baseline was 66.3 ± 9.2 y. During a mean follow up of 9.2 y, 1123 men (6.2%) developed DM. For self-reported chocolate consumption of none, 1-3 servings/mo, 1 serving/wk, and ≥2 servings/wk, multivariable-adjusted HRs (95% CIs) of DM adjusted for lifestyle, clinical, and dietary risk factors including total energy intake were 1.00 (referent), 0.93 (0.79, 1.09), 0.86 (0.72, 1.04), and 0.83 (0.69, 0.99), respectively (P-trend = 0.047). In secondary analyses, the inverse association of chocolate consumption and risk of DM was slightly stronger in subjects without a history of cardiovascular disease or heart failure (P-trend = 0.023). In addition, both age and BMI modified the chocolate-DM relation (P < 0.05 each). Our data support an inverse relation of chocolate intake with incident DM, which appears only to apply in younger and normal-body weight men after controlling for comprehensive life styles including total energy consumption.