Chocolate consumption and risk of myocardial infarction: a prospective study and meta-analysis

Objective To examine whether chocolate consumption is associated with a reduced risk of ischaemic heart disease, we used data from a prospective study of Swedish adults and we performed a meta-analysis of available prospective data. Methods and results The Swedish prospective study included 67 640 women and men from the Cohort of Swedish Men and the Swedish Mammography Cohort who had completed a food-frequency questionnaire and were free of cardiovascular disease at baseline. Myocardial infarction (MI) cases were ascertained through linkage with the Swedish National Patient and Cause of Death Registers. PubMed and EMBASE databases were searched from inception until 4 February 2016 to identify prospective studies on chocolate consumption and risk of ischaemic heart disease. Results The results from eligible studies were combined using a random-effects model. During follow-up (1998-2010), 4417 MI cases were ascertained in the Swedish study. Chocolate consumption was inversely associated with MI risk. Compared with non-consumers, the multivariable relative risk for those who consumed >= 3-4 servings/week of chocolate was 0.87 (95% CI 0.77 to 0.98; p for trend = 0.04). Five prospective studies on chocolate consumption and ischaemic heart disease were identified. Together with the Swedish study, the meta-analysis included six studies with a total of 6851 ischaemic heart disease cases. The overall relative risk for the highest versus lowest category of chocolate consumption was 0.90 (95% CI 0.82 to 0.97), with little heterogeneity among studies (I-2= 24.3%). Conclusions Chocolate consumption is associated with lower risk of MI and ischaemic heart disease.