Effects of Grape Seed Proanthocyanidin Extract on Vascular Endothelial Function in Participants with Prehypertension: A Randomized, Double-Blind, Placebo-Controlled Study

Nutrients. 2019 Nov 20;11(12):2844. doi: 10.3390/nu11122844.


This study aimed to investigate the effects of grape seed proanthocyanidin extract (GSPE) on blood pressure and vascular endothelial function in middle-aged Japanese adults with prehypertension. We conducted a randomized, double-blind, placebo-controlled study on 6 men and 24 women aged 40-64 years old. The participants were randomized to receive tablets containing either low-dose (200 mg/day) or high-dose (400 mg/day) GSPE, or placebo, for 12 weeks. Systolic and diastolic blood pressures (SBP and DBP, respectively), brachial flow-mediated dilation (FMD), and other cardiovascular parameters were measured before and after 4, 8, and 12 weeks of treatment. The mean SBP in the high-dose group significantly decreased by 13 mmHg after 12 weeks (P = 0.028), although FMD did not change. In an ad hoc analysis of non-smoking participants (n = 21), the mean SBP, DBP, stiffness parameter β, distensibility, incremental elastic modulus (Einc), and pulse wave velocity (PWV) also significantly improved in the high-dose group after 12 weeks. Changes in Einc and PWV from baseline to 12 weeks were significantly greater in the high-dose group than in the placebo group (Einc, P = 0.023; PWV, P = 0.03). GSPE consumption could help maintain vascular elasticity and normal blood pressure in this population.

Keywords: flavonoids; flow-mediated dilation; hypertension; polyphenols; vascular elasticity; vascular stiffness.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Antihypertensive Agents / administration & dosage*
  • Antihypertensive Agents / adverse effects
  • Blood Pressure / drug effects*
  • Brachial Artery / drug effects*
  • Brachial Artery / physiopathology
  • Dietary Supplements* / adverse effects
  • Double-Blind Method
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / physiopathology
  • Female
  • Grape Seed Extract / administration & dosage*
  • Grape Seed Extract / adverse effects
  • Humans
  • Male
  • Middle Aged
  • Prehypertension / diagnosis
  • Prehypertension / drug therapy*
  • Prehypertension / physiopathology
  • Proanthocyanidins / administration & dosage*
  • Proanthocyanidins / adverse effects
  • Time Factors
  • Tokyo
  • Treatment Outcome
  • Vascular Stiffness / drug effects
  • Vasodilation / drug effects


  • Antihypertensive Agents
  • Grape Seed Extract
  • Grape Seed Proanthocyanidins
  • Proanthocyanidins