Introduction: Dark chocolate and cocoa intakes are associated with a reduced risk of cardiovascular disease and cardiovascular mortality. Since no prior research has been published on the relationship between chocolate intake and heart failure (HF). Existing observational studies that evaluated the risk of HF with chocolate consumption show conflicting results and are not directly applicable to the general population.
Purpose: The purpose of this study was to investigate the associations among chocolate consumption and the risk of HF.
Methods: We conducted a comprehensive search of MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Scopus, and the Cochrane Central Register of Controlled Trials from database inception through April 2017. Observational studies that reported hazard ratios (HRs) or odd ratios (ORs) of the associations between chocolate consumption and HF were included. Data were extracted by one reviewer and then reviewed by two independent reviewers. Any conflicts were resolved through consensus. Using the DerSimonian and Laird random effects models, we calculated pooled HRs and pooled ORs with 95% confidence intervals (95% CIs). Subgroup analyses were performed to explore potential sources of heterogeneity. The quality of the included studies and the publication bias were assessed.
Results: From the 224 retrieved articles, we identified 5 prospective studies with 575,852 individuals and 24,649 HF events. Moderate chocolate consumption (1–3 servings/month) was associated with a 23% lower risk of HF (pooled risk ratio [RR], 0.87; 95% confidence interval [CI]: 0.77–0.98; p=0.36; I2 = 2.21%) than no regular chocolate intake. In contrast, high chocolate consumption (≥1 servings/day) was associated with a 17% higher risk of HF (pooled RR, 1.17; 95% CI: 1.12–1.60; p=0.82; I2 = 0%) than no regular chocolate intake.
Conclusions: The present study confirms the association of high chocolate consumption with the risk of HF. In contrast, moderate chocolate consumption may reduce the risk of HF. Limit daily chocolate consumption may be needed. However, further prospective studies are needed to identify residual confounders.