Effect of Grape Polyphenols on Blood Pressure: A Meta-Analysis of Randomized Controlled Trials

Study answer

What this study found

Daily grape polyphenol intake modestly reduced systolic blood pressure overall, but it did not significantly reduce diastolic blood pressure. For systolic blood pressure, 12 comparisons showed a weighted mean difference of -1.48 mmHg (95% CI: -2.79 to -0.16; P = 0.03), with low heterogeneity (I2 = 32%, P = 0.14) and no evidence of publication bias. The blood pressure effect was larger in low-dose trials (< 733 mg/day) and in participants with metabolic syndrome, where systolic blood pressure fell by WMD:-7.05 mmHg (95% CI: -10.97 to -3.12). Overall, the findings support a small…

Study & population

Systematic review and meta-analysis of 10 randomized controlled trials in adults.

Intervention

Daily oral grape polyphenol supplementation was evaluated across randomized trials, with doses ranging from 150 mg/day to 1400 mg/day.

Key limitation

The evidence base was small and heterogeneous in terms of population, dose, and background lifestyle factors.

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Original abstract