title: Flavonoid-rich dark chocolate improves endothelial function and increases plasma epicatechin concentrations in healthy adults.
abstract: BACKGROUND
  Dark chocolate derived from the plant (Theobroma cacao) is a rich source of flavonoids. Cardioprotective effects including antioxidant properties, inhibition of platelet activity, and activation of endothelial nitric oxide synthase have been ascribed to the cocoa flavonoids.
  
  
  OBJECTIVE
  To investigate the effects of flavonoid-rich dark chocolate on endothelial function, measures of oxidative stress, blood lipids, and blood pressure in healthy adult subjects.
  
  
  METHODS
  The study was a randomized, double-blind, placebo-controlled design conducted over a 2 week period in 21 healthy adult subjects. Subjects were randomly assigned to daily intake of high-flavonoid (213 mg procyanidins, 46 mg epicatechin) or low-flavonoid dark chocolate bars (46 g, 1.6 oz).
  
  
  RESULTS
  High-flavonoid chocolate consumption improved endothelium-dependent flow-mediated dilation (FMD) of the brachial artery (mean change = 1.3 +/- 0.7%) as compared to low-flavonoid chocolate consumption (mean change = -0.96 +/- 0.5%) (p = 0.024). No significant differences were noted in the resistance to LDL oxidation, total antioxidant capacity, 8-isoprostanes, blood pressure, lipid parameters, body weight or body mass index (BMI) between the two groups. Plasma epicatechin concentrations were markedly increased at 2 weeks in the high-flavonoid group (204.4 +/- 18.5 nmol/L, p < or = 0.001) but not in the low-flavonoid group (17.5 +/- 9 nmol/L, p = 0.99).
  
  
  CONCLUSIONS
  Flavonoid-rich dark chocolate improves endothelial function and is associated with an increase in plasma epicatechin concentrations in healthy adults. No changes in oxidative stress measures, lipid profiles, blood pressure, body weight or BMI were seen.
authors.affiliation: Laboratory of Cardiovascular Physiology, Department of Physiological Nursing, University of California, San Francisco, 94143-0610, USA. mary.engler@nursing.ucsf.edu
authors.forename: Mary B
authors.initials: MB
authors.lastname: Engler
authors.forename: Marguerite M
authors.initials: MM
authors.lastname: Engler
authors.forename: Chung Y
authors.initials: CY
authors.lastname: Chen
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Malloy
authors.forename: Amanda
authors.initials: A
authors.lastname: Browne
authors.forename: Elisa Y
authors.initials: EY
authors.lastname: Chiu
authors.forename: Ho-Kyung
authors.initials: HK
authors.lastname: Kwak
authors.forename: Paul
authors.initials: P
authors.lastname: Milbury
authors.forename: Steven M
authors.initials: SM
authors.lastname: Paul
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Blumberg
authors.forename: Michele L
authors.initials: ML
authors.lastname: Mietus-Snyder
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000975:Antioxidants / Q000008:administration & dosage; D044946:Biflavonoids; D001794:Blood Pressure / Q000187:drug effects; D015992:Body Mass Index; D001835:Body Weight / Q000187:drug effects; D001916:Brachial Artery / Q000187:drug effects / Q000502:physiology; D002099:Cacao; D002182:Candy; D002392:Catechin / Q000008:administration & dosage / Q000097:blood*; D004311:Double-Blind Method; D004727:Endothelium / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D044945:Proanthocyanidins; D012016:Reference Values
chemical_list: D000975:Antioxidants; D044946:Biflavonoids; D005419:Flavonoids; D008055:Lipids; D044945:Proanthocyanidins; D009569:Nitric Oxide; C017674:procyanidin; D002392:Catechin