Effects on Peripheral and Central Blood Pressure of Cocoa With Natural or High-Dose Theobromine A Randomized, Double-Blind Crossover Trial

Flavanol-rich cocoa products have been reported to lower blood pressure. It has been suggested that theobromine is partially responsible for this effect. We tested whether consumption of flavanol-rich cocoa drinks with natural or added theobromine could lower peripheral and central blood pressure. In a double-blind, placebo-controlled 3-period crossover trial we assigned 42 healthy individuals (age 62 +/- 4.5 years; 32 men) with office blood pressure of 130 to 159 mm Hg/85 to 99 mm Hg and low added cardiovascular risk to a random treatment sequence of dairy drinks containing placebo, flavanol-rich cocoa with natural dose consisting of 106 mg of theobromine, or theobromine-enriched flavanol-rich cocoa with 979 mg of theobromine. Treatment duration was 3 weeks with a 2-week washout. The primary outcome was the difference in 24-hour ambulatory systolic blood pressure between placebo and active treatment after 3 weeks. The difference in central systolic blood pressure between placebo and active treatment was a secondary outcome. Treatment with theobromine-enriched cocoa resulted in a mean +/- SE of 3.2 +/- 1.1 mm Hg higher 24-hour ambulatory systolic blood pressure compared with placebo (P<0.01). In contrast, 2 hours after theobromine-enriched cocoa, laboratory peripheral systolic blood pressure was not different from placebo, whereas central systolic blood pressure was 4.3 +/- 1.4 mm Hg lower (P=0.001). Natural dose theobromine cocoa did not significantly change either 24-hour ambulatory or central systolic blood pressure compared with placebo. In conclusion, theobromine-enriched cocoa significantly increased 24-hour ambulatory systolic blood pressure while lowering central systolic blood pressure. (Hypertension. 2010;56:839-846.)