Impact of cocoa flavanol consumption on blood pressure responsiveness to exercise

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, 549 (se 22) years, BMI 316 (se 08)kg/m², systolic BP 134 (se 2)mmHg, diastolic BP (DBP) 87 (se 2)mmHg) were randomised to consume single servings of either a high-flavanol (HF, 701mg) or a low-flavanol (LF, 22mg) 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 10min 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 (se 3)/88 (se 3) v. 153 (se 4)/87 (se 2)mmHg, respectively, P>005). 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=003) and 14% lower for mean BP (P=005). FMD measurements were higher after taking HF than after taking LF (61 (se 06) % v. 34 (se 05) %, P<0001). 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.