Red Grape and Reduced Stroke Volume

Research synthesisLow evidenceSmall effect3 studies · 0 beneficial · 3 neutral · 0 harmful

Across 3 studies, all reported neutral small-sized effects on stroke volume with grape seed extract supplementation. No statistically significant findings were observed. The studies focused on overweight/obese males and males with elevated or stage 1 hypertension, with a median study duration of 7 days.

Studied populations: overweight and obese males; males with elevated or stage 1 hypertension

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. All findings were neutral, and no significant improvements in stroke volume were reported.

Generated Jul 16, 2026

Time to effect

Median: 7 days · IQR 7 days–7 days · Range 7 days–7 days — Reported in 2 of 3 studies

3 of 3 papersPopulation:

Effect of 7-day dietary supplementation with grape seed extract on cardiac autonomic and hemodynamic responses in elevated and stage 1 hypertension.
- 2025-05
- RCT
- Clinical physiology and functional imaging 45(3)
- - Albert Lira
  - William Boyer
  - Trevor Gillum
  - Sean Sullivan
  - Jong-Kyung Kim
- PubMed: 40341867
- DOI: 10.1111/cpf.70010
8 Insights on
- Reduced Stroke Volume
- High evidence
There were no differences on the SV … between placebo and GSE treatments
Effect
Neutral
Effect size
Small
Significant
No
Effects of Acute Grape Seed Extract Supplementation on Hemodynamics in Normal Body Weight and Obese Males.
- 2020-10-31
- RCT
- Journal of nutritional science and vitaminology 66(5)
- - Katherine N Dillon
  - Brian Shariffi
  - Brittany Thompson
  - Richard Steele
  - Jong-Kyung Kim
- PubMed: 33132345
- DOI: 10.3177/jnsv.66.427
8 Insights on
- Reduced Stroke Volume
- High evidence
- Clinical
while there were no differences in HR, SV, DBP, TPR, and AoS.
Effect
Neutral
Effect size
Small
Significant
No
Effects of chronic dietary grape seed extract supplementation on aortic stiffness and hemodynamic responses in obese/overweight males during submaximal exercise.
- 2021-05-20
- Clinical Trial
- European journal of sport science 22(7)
- - Katherine Dillon
  - Brian Shariffi
  - Trevor Gillum
  - William Boyer
  - Sean Sullivan
  - Jong-Kyung Kim
- PubMed: 33905304
- DOI: 10.1080/17461391.2021.1923815
6 Insights on
- Reduced Stroke Volume
- High evidence
- Clinical
GSE had no effect on HR, TVC, and SV.
Effect
Neutral
Effect size
Small
Significant
No

Red Grape and Reduced Stroke Volume

Effect of 7-day dietary supplementation with grape seed extract on cardiac autonomic and hemodynamic responses in elevated and stage 1 hypertension.

Effects of Acute Grape Seed Extract Supplementation on Hemodynamics in Normal Body Weight and Obese Males.

Effects of chronic dietary grape seed extract supplementation on aortic stiffness and hemodynamic responses in obese/overweight males during submaximal exercise.