title: Epicatechin ingested via cocoa products reduces blood pressure in humans: a nonlinear regression model with a Bayesian approach.
abstract: BACKGROUND
  Four meta-analyses of randomized controlled trials (RCTs) based on the classical random-effects model showed that cocoa consumption can reduce systolic blood pressure (SBP) and diastolic blood pressure (DBP). Because epicatechin is suggested to be responsible for the treatment effect, changes in blood pressure should depend on the dose of ingested epicatechin, which may explain the between-study differences.
  
  
  OBJECTIVE
  The objective was to quantify the effect of epicatechin ingested via cocoa products on changes in SBP and DBP.
  
  
  METHODS
  A nonlinear meta-regression model was chosen to investigate the impact of the epicatechin dose on changes in SBP and DBP. A Bayesian approach using Markov chain Monte Carlo methods was applied for an appropriate treatment of the nonlinearity.
  
  
  RESULTS
  Data from 16 RCTs on SBP and 15 RCTs on DBP were included. The dose of epicatechin ingested via cocoa products influenced the changes in SBP and DBP. The asymptotic limit for the reduction was estimated at -4.6 mm Hg (95% CI: -5.4, -3.9 mm Hg) for SBP and at -2.1 mm Hg (95% CI: -2.7, -1.6 mm Hg) for DBP. An intake of 25 mg epicatechin/d led to a mean reduction of -4.1 mm Hg (95% CI: -4.6, -3.6 mm Hg) in SBP and of -2.0 mm Hg (95% CI: -2.4, -1.5 mm Hg) in DBP.
  
  
  CONCLUSIONS
  Blood pressure reduction by consumption of cocoa products depends on the dose of ingested epicatechin, which explains most of the between-study differences in classical meta-analyses. Similar effects may be achieved by consumption of other foods that are also rich in epicatechin.
authors.affiliation: Department of Nutrition and Food Science-Nutritional Physiology, University of Bonn, Bonn, Germany. ellinger@uni-bonn.de
authors.forename: Sabine
authors.initials: S
authors.lastname: Ellinger
authors.forename: Andreas
authors.initials: A
authors.lastname: Reusch
authors.forename: Peter
authors.initials: P
authors.lastname: Stehle
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Helfrich
mesh_terms: D001499:Bayes Theorem; D001794:Blood Pressure / Q000187:drug effects*; D002099:Cacao / Q000737:chemistry*; D002392:Catechin / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D004032:Diet; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000517:prevention & control*; D008954:Models, Biological; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D012044:Regression Analysis
chemical_list: D010936:Plant Extracts; D002392:Catechin