Flavan-3-ol-enriched dark chocolate and white chocolate improve acute measures of platelet function in a gender-specific way--a randomized-controlled human intervention trial.

ScopeWe examined whether flavan-3-ol-enriched dark chocolate, compared with standard dark and white chocolate, beneficially affects platelet function in healthy subjects, and whether this relates to flavan-3-ol bioavailability. Methods and resultsA total of 42 healthy subjects received an acute dose of flavan-3-ol-enriched dark, standard dark or white chocolate, in random order. Blood and urine samples were obtained just before and 2 and 6 h after consumption for measurements of platelet function, and bioavailability and excretion of flavan-3-ols. Flavan-3-ol-enriched dark chocolate significantly decreased adenosine diphosphate-induced platelet aggregation and P-selectin expression in men (all p = 0.020), decreased thrombin receptor-activating peptide-induced platelet aggregation and increased thrombin receptor-activating peptide-induced fibrinogen binding in women (both p = 0.041), and increased collagen/epinephrine-induced ex vivo bleeding time in men and women (p = 0.042). White chocolate significantly decreased adenosine diphosphate-induced platelet P-selectin expression (p = 0.002) and increased collagen/epinephrine-induced ex vivo bleeding time (p = 0.042) in men only. Differences in efficacy by which flavan-3-ols affect platelet function were only partially explained by concentrations of flavan-3-ols and their metabolites in plasma or urine. ConclusionFlavan-3-ols in dark chocolate, but also compounds in white chocolate, can improve platelet function, dependent on gender, and may thus beneficially affect atherogenesis.