ABSTRACT
BACKGROUND: Some previous works have focused on dose-response relationship between cocoa consumption and blood pressure in Caucasians. As black subjects have lower nitric oxide bioavailability, the aim of this work was to determine the dose-effect relation between cocoa and blood pressure in black Africans. METHOD: One hundred and thirty healthy black African males aged 18-30 were randomly assigned into four groups: three groups consuming 10 g, 5 g, or 2 g of cocoa powder daily for three weeks and one control group that did not consume cocoa. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were measured on day 1 (D1, before any subject consumed cocoa), D8, D15, and D22. Means of the parameters at each of the four visits and changes of the means were compared among the groups. RESULTS: Significant decrease in SBP was noted in consumers of 10 g compared to controls in the 1st week, and compared to consumers of 2 g in the 2nd and 3rd weeks of follow-up. Means and changes of DBP were statistically similar among the four groups. CONCLUSION: Among our cohort, decrease in SBP was significantly greater in the heavy cocoa consumer group (10 g) compared to the low consumer group (2 g), but there was no statistically significant difference when compared with the intermediate consumer group (5 g). The dose-response relationship between cocoa consumption and changes in SBP was not linear. No relationship was found between cocoa consumption and DBP.
