The authors of this meta-analysis aimed to investigate the effects of dark chocolate on flow-mediated dilation (FMD). 17 randomized clinical trials have been compiled, for a total of 615 participants.

Chronic consumption of dark chocolate and flavan-3-ol both increased FMD (p < 0.001 and p = 0.001 respectively). Acute consumption of dark chocolate (p < 0.001) and both dark chocolate and flavonoids (p < 0.001) improved also FMD. Regarding doses, it seems that 40 g/day of flavonoids increases FMD with the highest mean of FMD in doses around 40 to 60 g/day. Regarding dark chocolate, the greater reduction in FMD was obtained with doses lower than 20 g/day.

Therefore, this meta-analysis confirms the beneficial effects of dark chocolate on FMD.

Ebaditabar M, Djafarian K, Saeidifard N, Shab-Bidar S. Effect of dark chocolate on flow-mediated dilatation: Systematic review, meta-analysis, and dose-response analysis of randomized controlled trials. Clin Nutr ESPEN. 2020 Apr;36:17-27.