Milk decreases urinary excretion but not plasma pharmacokinetics of cocoa flavan-3-ol metabolites in humans

Mullen, W. , Borges, G.,, Donovan, J.L., Edwards, C.A. , Serafini, M., Lean, M.E.J. and Crozier, A. (2009) Milk decreases urinary excretion but not plasma pharmacokinetics of cocoa flavan-3-ol metabolites in humans. American Journal of Clinical Nutrition, 89(6), pp. 1784-1791. (doi: 10.3945/ajcn.2008.27339) (PMID:19403635)

Full text not currently available from Enlighten.


<b>Background:</b> Cocoa drinks containing flavan-3-ols are associated with many health benefits, and conflicting evidence exists as to whether milk adversely affects the bioavailability of flavan-3-ols. <b>Objective:</b> The objective was to determine the effect of milk on the bioavailability of cocoa flavan-3-ol metabolites. Design: Nine human volunteers followed a low-flavonoid diet for 2 d before drinking 250 mL of a cocoa beverage, made with water or milk, that contained 45 mu mol (-)-epicatechin and (-)-catechin. Plasma and urine samples were collected for 24 h, and flavan-3-ol metabolites were analyzed by HPLC with photodiode array and mass spectrometric detection. <b>Results:</b> Milk affected neither gastric emptying nor the transit time through the small intestine. Two flavan-3-ol metabolites were detected in plasma and 4 in urine. Milk had only minor effects on the plasma pharmacokinetics of an (epi) catechin-O-sulfate and had no effect on an O-methyl-(epi) catechin-O-sulfate. However, milk significantly lowered the excretion of 4 urinary flavan-3-ol metabolites from 18.3% to 10.5% of the ingested dose (P=0.016). Studies that showed protective effects of cocoa and those that showed no effect of milk on bioavailability used products that have a much higher flavan 3-ol content than does the commercial cocoa used in the present study. <b>Conclusions:</b> Most studies of the protective effects of cocoa have used drinks with a very high flavan-3-ol content. Whether similar protective effects are associated with the consumption of many commercial chocolate and cocoa products containing substantially lower amounts of flavan-3-ols, especially when absorption at lower doses is obstructed by milk, remains to be determined.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Borges, Dr Gina and Mullen, Dr Bill and Edwards, Professor Christine and Lean, Professor Michael and Crozier, Professor Alan
Authors: Mullen, W., Borges, G.,, Donovan, J.L., Edwards, C.A., Serafini, M., Lean, M.E.J., and Crozier, A.
Subjects:Q Science > QP Physiology
R Medicine > RA Public aspects of medicine
College/School:College of Medical Veterinary and Life Sciences
College of Medical Veterinary and Life Sciences > Institute of Cancer Sciences
College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
Journal Name:American Journal of Clinical Nutrition
Publisher:American Society for Nutrition
ISSN (Online):1938-3207
Published Online:29 April 2009

University Staff: Request a correction | Enlighten Editors: Update this record