Chocolate consumption and risk of diabetes mellitus in the physicians' health study

Abstract

Background: 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. Objective: We tested the hypothesis that chocolate consumption is inversely associated with incident DM in the Physicians' Health Study (PHS). Design: 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. Results: 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). Conclusion: 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.