Impact of cocoa flavanol consumption on blood pressure responsiveness to exercise

Abstract

Impaired endothelial vasodilatation may contribute to the exaggerated blood pressure (BP) responses to exercise in individuals who are overweight/obese. The present study investigated whether consumption of cocoa flavanols, which improve endothelium-dependent flow-mediated dilatation (FMD), can modify BP responsiveness to exercise. Twenty-one volunteers (eight females and thirteen males, 54·9 (se2·2) years, BMI 31·6 (se0·8) kg/m2, systolic BP 134 (se2) mmHg, diastolic BP (DBP) 87 (se2) mmHg) were randomised to consume single servings of either a high-flavanol (HF, 701 mg) or a low-flavanol (LF, 22 mg) cocoa beverage in a double-blind, cross-over design with 3–7-d washout between treatments. Two hours after cocoa consumption, FMD was measured, followed by continuous beat-to-beat assessment (Finapres™) of BP before and during 10 min of cycling at 75 % of age-predicted maximum heart rate. Averaged data from two assessments on each type of beverage were compared by analysis of covariance using pre-exercise BP as the covariate. Pre-exercise BP was similar after taking LF and HF (153 (se3)/88 (se3)v. 153 (se4)/87 (se2) mmHg, respectively,P>0·05). However, the BP response to exercise (area under BP curve) was attenuated by HF compared with LF. BP increases were 68 % lower for DBP (P = 0·03) and 14 % lower for mean BP (P = 0·05). FMD measurements were higher after taking HF than after taking LF (6·1 (se0·6) %v. 3·4 (se0·5) %,P < 0·001). By facilitating vasodilation and attenuating exercise-induced increases in BP, cocoa flavanols may decrease cardiovascular risk and enhance the cardiovascular benefits of moderate intensity exercise in at-risk individuals.