From Effect of cocoa on blood pressure by Australian researchers Ried K, Fakler P, Stocks NP. A review article first published in 2012 and updated in 2016 based on thirty-five trials. Cochrane Database of Systematic Reviews, 2017 Apr 25.
Meta‐analyses of the 40 treatment comparisons revealed a small but statistically significant blood pressure‐reducing effect of flavanol‐rich cocoa products compared with control in trials:
- Flavanol‐rich chocolate and cocoa products cause a small blood pressure‐lowering effect in mainly healthy adults in the short term.
- Slight reduction in Systolic AND Diastolic Blood Pressure (‐1.76)
- Systolic blood pressure was reduced significantly in hypertensive people
- Younger participants responding with greater blood pressure reduction
Equivalent Serving Size: "Trials provided participants with 30 to 1218 mg of flavanols (mean = 670 mg) in 1.4 to 105 grams of cocoa products per day in the active intervention group." From estimates based on this article published by Yale researchers, equivalent 100% cocoa bean servings would range from 2-87g (the same as cocoa liquor) per day, with mean = 48g.