title: Supplementation of the Pure Flavonoids Epicatechin and Quercetin Affects Some Biomarkers of Endothelial Dysfunction and Inflammation in (Pre)Hypertensive Adults: A Randomized Double-Blind, Placebo-Controlled, Crossover Trial.
abstract: BACKGROUND
  Consumption of flavonoid-rich foods such as cocoa and tea may reduce cardiovascular disease risk. The flavonoids epicatechin (in cocoa and tea) and quercetin (in tea) probably play a role by reducing endothelial dysfunction and inflammation, 2 main determinants of atherosclerosis.
  
  
  OBJECTIVE
  We studied the effects of supplementation of pure epicatechin and quercetin on biomarkers of endothelial dysfunction and inflammation.
  
  
  METHODS
  Thirty-seven apparently healthy (pre)hypertensive men and women (40-80 y) participated in a randomized, double-blind, placebo-controlled crossover trial. Participants ingested (-)-epicatechin (100 mg/d), quercetin-3-glucoside (160 mg/d), or placebo capsules for a period of 4 wk, in random order. Plasma biomarkers of endothelial dysfunction and inflammation were measured at the start and end of each 4-wk intervention period. The differences in changes over time between the intervention and placebo periods (Δintervention - Δplacebo) were calculated and tested with a linear mixed model for repeated measures.
  
  
  RESULTS
  Epicatechin changed Δepicatechin - Δplacebo for soluble endothelial selectin (sE-selectin) by -7.7 ng/mL (95% CI: -14.5, -0.83; P = 0.03) but did not significantly change this difference (-0.30; 95% CI: -0.61, 0.01; P = 0.06) for the z score for endothelial dysfunction. Quercetin changed Δquercetin - Δplacebo for sE-selectin by -7.4 ng/mL (95% CI: -14.3, -0.56; P = 0.03), that for IL-1β by -0.23 pg/mL (95% CI: -0.40, -0.06; P = 0.009), and that for the z score for inflammation by -0.33 (95% CI: -0.60, -0.05; P = 0.02).
  
  
  CONCLUSIONS
  In (pre)hypertensive men and women, epicatechin may contribute to the cardioprotective effects of cocoa and tea through improvements in endothelial function. Quercetin may contribute to the cardioprotective effects of tea possibly by improving endothelial function and reducing inflammation. This trial was registered at clinicaltrials.gov as NCT01691404.
authors.affiliation: Top Institute Food and Nutrition, Wageningen, The Netherlands; Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; and.
authors.forename: James I
authors.initials: JI
authors.lastname: Dower
authors.affiliation: Top Institute Food and Nutrition, Wageningen, The Netherlands; Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; and.
authors.forename: Johanna M
authors.initials: JM
authors.lastname: Geleijnse
authors.affiliation: Top Institute Food and Nutrition, Wageningen, The Netherlands; Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; and.
authors.forename: Lieke
authors.initials: L
authors.lastname: Gijsbers
authors.affiliation: Top Institute Food and Nutrition, Wageningen, The Netherlands; Department of Internal Medicine, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Casper
authors.initials: C
authors.lastname: Schalkwijk
authors.affiliation: Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; and.
authors.forename: Daan
authors.initials: D
authors.lastname: Kromhout
authors.affiliation: Top Institute Food and Nutrition, Wageningen, The Netherlands; Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands; and peter.hollman@wur.nl.
authors.forename: Peter C
authors.identifier: http://orcid.org/0000-0002-7510-6809
authors.initials: PC
authors.lastname: Hollman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D002392:Catechin / Q000008:administration & dosage*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D019040:E-Selectin / Q000097:blood; D004730:Endothelium, Vascular / Q000187:drug effects; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood*; D053583:Interleukin-1beta / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D016209:Interleukin-8 / Q000097:blood; D008297:Male; D008875:Middle Aged; D058246:Prehypertension / Q000097:blood*; D011794:Quercetin / Q000008:administration & dosage* / Q000031:analogs & derivatives; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D019040:E-Selectin; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha; C016527:isoquercitrin; D002392:Catechin; D002097:C-Reactive Protein; D011794:Quercetin
keywords: CVD; atherosclerosis; clinical trial; endothelial dysfunction; epicatechin; flavonoids; inflammation; quercetin