Red Grape and Reduced Heart Rate

Research synthesisLow evidenceSmall effect4 studies · 1 beneficial · 3 neutral · 0 harmful

Across 4 studies on red grape seed extract for reduced heart rate, 1 reported a beneficial effect (meta-analysis: WMD -1.25 bpm) and 3 reported neutral effects, yielding a small predominant effect size. Evidence is mixed, with most individual RCTs failing to find significant differences.

Caveats: Many of the included studies did not reach statistical significance — effect may be smaller than the beneficial signal suggests. Evidence base is small (only 4 studies) — conclusions should be considered preliminary. The only significant finding comes from a meta-analysis; individual trials showed no effect.

Generated Jul 16, 2026

Time to effect

Median: 7 days · IQR 7 days–7 days · Range 7 days–7 days — Reported in 2 of 4 studies

4 of 4 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 Heart Rate
- High evidence
There were no differences on the HR … 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 Heart Rate
- 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 Heart Rate
- High evidence
- Clinical
GSE had no effect on HR, TVC, and SV.
Effect
Neutral
Effect size
Small
Significant
No
The effect of grape (Vitis vinifera) seed extract supplementation on flow-mediated dilation, blood pressure, and heart rate: A systematic review and meta-analysis of controlled trials with duration- and dose-response analysis.
- 2022-01
- Meta-Analysis
- Pharmacological research 175
- - Sahar Foshati
  - Fatemeh Nouripour
  - Erfan Sadeghi
  - Reza Amani
- PubMed: 34798267
- DOI: 10.1016/j.phrs.2021.105905
4 Insights on
- Reduced Heart Rate
- High evidence
GSE supplementation significantly reduced ... HR (WMD: -1.25 bpm, 95% CI: -2.32 to -0.19, I² = 59.5%)
Effect
Beneficial
Effect size
Small
Significant
Yes
Dose
varied across trials

Red Grape and Reduced Heart Rate

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.

The effect of grape (Vitis vinifera) seed extract supplementation on flow-mediated dilation, blood pressure, and heart rate: A systematic review and meta-analysis of controlled trials with duration- and dose-response analysis.