Garlic Supplementation and Cardiovascular Risk: Meta-Analysis of 108 Randomized Trials

This meta-analysis, published in Nutrition Reviews (January 2026), pooled data from 108 randomized controlled trials involving 7,137 adult participants to evaluate garlic supplementation's effects on cardiovascular risk factors, making it one of the most comprehensive garlic-cardiovascular reviews ever conducted.

The Research at a Glance

Core finding: Garlic supplementation produced statistically significant improvements across virtually every major cardiovascular risk marker (lipids, blood pressure, blood glucose, inflammation, and oxidative stress) particularly in adults who already had unfavorable baseline risk profiles.

The Dose-Response Relationship

The most robust outcomes appeared with daily doses of 600-1200 mg of garlic powder (standardized to allicin content) taken for at least 8-12 weeks. Key effect sizes vs placebo: Total cholesterol down 10.2 mg/dL, LDL down 5.9 mg/dL, HDL up 2.2 mg/dL, Systolic BP down 3.7 mmHg, Diastolic BP down 2.0 mmHg, Fasting glucose down 2.8 mg/dL, C-reactive protein down 1.6 mg/L.

How It Works (Mechanisms)

Garlic's cardiovascular effects are mediated through multiple parallel biological pathways: HMG-CoA reductase inhibition, Nitric oxide/H2S vasodilation, Anti-inflammatory signaling via NF-kB suppression, Antioxidant upregulation, and Insulin sensitization through AMPK and PPAR-g pathways.

Source: Nutrition Reviews, 2026. Behrouz V, et al. DOI: 10.1093/nutrit/nuaf090. PMID: 40580481