In January 2017 researchers from the USA and Sweden published the results of their study to assess the association between chocolate consumption and heart failure. 31,917 men aged 45-79 years, with no history of heart attack, diabetes, or heart failure were included in the study. Information on chocolate consumption was collected via a self-administrated food frequency questionnaire. During a 14-year follow up period 1,901 men were hospitalized and 256 died from heart failure. Results showed that there was a reducing risk of hospitalization or dying from heart failure up to 3-6 servings per week of chocolate, but the protective effect of chocolate was not observed among individuals consuming 1 serving or more per day.
Steinhaus DA et al. Chocolate intake and incidence of heart failure: Findings from the Cohort of Swedish Men. Am Heart J. 2017 Jan;183:18-23