British Journal of Nutrition

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British Journal of Nutrition (2010), 103:1480-1484 Cambridge University Press
Copyright © The Authors 2009
doi:10.1017/S0007114509993382

Full Papers

Human and Clinical Nutrition

Impact of cocoa flavanol consumption on blood pressure responsiveness to exercise


Narelle M. Berrya1 c1, Kade Davisona1a2, Alison M. Coatesa1, Jonathan D. Buckleya1 and Peter R. C. Howea1

a1 School of Health Sciences, Nutritional Physiology Research Centre and ATN Centre for Metabolic Fitness, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia
a2 School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, SA 5005, Australia
Article author query
berry nm [PubMed]  [Google Scholar]
davison k [PubMed]  [Google Scholar]
coates am [PubMed]  [Google Scholar]
buckley jd [PubMed]  [Google Scholar]
howe prc [PubMed]  [Google Scholar]

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 (se 2·2) years, BMI 31·6 (se 0·8) 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, 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 (se 3)/88 (se 3) v. 153 (se 4)/87 (se 2) 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 (se 0·6) % v. 3·4 (se 0·5) %, 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.

(Received August 14 2009)

(Revised October 27 2009)

(Accepted November 11 2009)

(Online publication January 19 2010)

Key Words:Blood pressure; Exercise; Endothelium; Flow-mediated dilatation; Cocoa; Flavanols

Correspondence:

c1 Corresponding author: Dr Narelle M. Berry, fax +61 8 8302 2178, email narelle.berry@unisa.edu.au

Footnotes

Abbreviations: BP, blood pressure; FMD, flow-mediated dilatation; HF, high flavanol; HR, heart rate; LF, low flavanol; SBP, systolic blood pressure