Grape seed extract significantly reduces blood pressure, meta-analysis shows
- Meta-analysis of 16 randomized, placebo-controlled clinical trials comprising 810 subjects
- Grape seed extract (GSE) dosages from 100 to 2,000 mg/day for 2 to 12 weeks
- GSE significantly reduces blood pressure compared to placebo
- Benefits more obvious in younger, overweight people and patients with metabolic disorders
This meta-analysis was designed to evaluate the effects of grape seed extract (GSE) on blood pressure. Inclusion criteria included randomized, placebo-controlled, clinical trials published in the peer-reviewed literature, retrieved from PubMed or Embase (up to November 20, 2015) that included treatment lasting at least 2 weeks and available data on changes in blood pressure.
Sixteen studies met the inclusion criteria and were included in the meta-analysis (12 parallel design; 5 crossover design). Study durations ranged from 2 to 12 weeks with GSE dosages ranging from 100 to 2,000 mg/day. Trials were conducted in Asia, America, Europe, and Australia. Participants included patients with pre- and stage 1 hypertension (4 trials), healthy participants (4 trials), patients with metabolic syndrome (3 trials) or high blood pressure (2 trials), women with at least one menopausal symptom (2 trials), and patients at high vascular risk (1 trial).
No indication of publication bias was reported. Study design, randomization, and baseline blood pressure were identified as possible causes of heterogeneity.
Results indicate that, compared to placebo, GSE significantly reduced both systolic and diastolic blood pressure. Subgroup analyses indicate this effect was more obvious in younger people (<50 years), overweight people (BMI ≥25 kg/m2) and patients with metabolic disorders (see Table). Reductions in blood pressure were more obvious in longer duration trials (8 weeks or more) and with lower dosages of phenols (<800mg/day).
|Parameter||Weighted Mean Difference|
|SBP||-6.077 (95% CI: -10.736 to -1.419; P=.011)|
|DBP||-2.803 (95% CI: -4.417 to -1.189; P=.001)|
|SBP (age <50 y)||-6.049 (95% CI: -10.223 to -1.875; P=.005)|
|DBP (age <50 y)||-3.116 (95% CI: -4.773 to -1.459; P< .001)|
|WBP (BMI ≥25 kg/m2)||-4.469 (95% CI: -6.628 to -2.310; P<.001)|
|SBP (MetSx)||-8.487 (95% CI: -11.869 to -5.106; P<.001)|
|SBP indicates systolic blood pressure; DBP, diastolic blood pressure; BMI, body mass index; MetSx, metabolic syndrome; CI, confidence interval.|
The authors note that this is the largest meta-analysis to date to evaluate the effect of GSE supplementation on blood pressure.
These findings indicate that GSE supplementation has clinical value for blood pressure control, especially in younger, overweight people or people who have metabolic syndrome.