title: Effect of cocoa products on blood pressure: systematic review and meta-analysis.
abstract: BACKGROUND
  Cocoa products such as dark chocolate and cocoa beverages may have blood pressure (BP)-lowering properties due to their high content of plant-derived flavanols.
  
  
  METHODS
  We performed a meta-analysis of randomized controlled trials assessing the antihypertensive effects of flavanol-rich cocoa products. The primary outcome measure was the change in systolic and diastolic BP between intervention and control groups.
  
  
  RESULTS
  In total, 10 randomized controlled trials comprising 297 individuals were included in the analysis. The populations studied were either healthy normotensive adults or patients with prehypertension/stage 1 hypertension. Treatment duration ranged from 2 to 18 weeks. The mean BP change in the active treatment arms across all trials was -4.5 mm Hg (95% confidence interval (CI), -5.9 to -3.2, P < 0.001) for systolic BP and -2.5 mm Hg (95% CI, -3.9 to -1.2, P < 0.001) for diastolic BP.
  
  
  CONCLUSIONS
  The meta-analysis confirms the BP-lowering capacity of flavanol-rich cocoa products in a larger set of trials than previously reported. However, significant statistical heterogeneity across studies could be found, and questions such as the most appropriate dose and the long-term side effect profile warrant further investigation before cocoa products can be recommended as a treatment option in hypertension.
authors.affiliation: Department of Cardiology, University of Leipzig-Heart Center, Leipzig, Germany. stdesch@web.de
authors.forename: Steffen
authors.initials: S
authors.lastname: Desch
authors.forename: Johanna
authors.initials: J
authors.lastname: Schmidt
authors.forename: Daniela
authors.initials: D
authors.lastname: Kobler
authors.forename: Melanie
authors.initials: M
authors.lastname: Sonnabend
authors.forename: Ingo
authors.initials: I
authors.lastname: Eitel
authors.forename: Mahdi
authors.initials: M
authors.lastname: Sareban
authors.forename: Kazem
authors.initials: K
authors.lastname: Rahimi
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schuler
authors.forename: Holger
authors.initials: H
authors.lastname: Thiele
mesh_terms: D001794:Blood Pressure; D002099:Cacao / Q000737:chemistry; D003971:Diastole; D004032:Diet; D005419:Flavonoids / Q000032:analysis; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D016032:Randomized Controlled Trials as Topic; D013599:Systole
chemical_list: D005419:Flavonoids