The Effect of Garlic Supplements on Lipid Profiles: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Abstract

Introduction: Hyperlipidemia is a major risk factor for cardiovascular disease. Garlic (Allium sativum) has been traditionally used to improve heart health. This meta-analysis aims to quantify the effect of garlic supplementation on blood lipid concentrations.

Methods: We searched PubMed and CENTRAL for placebo-controlled RCTs published up to November 2019 that evaluated the effect of garlic preparations on total cholesterol, LDL-C, HDL-C, and triglycerides in adults. A random-effects model was used for analysis.

Results: Thirty-nine RCTs met the inclusion criteria. The meta-analysis showed that garlic supplementation significantly reduced total cholesterol (Mean Difference [MD] = -17 mg/dL; 95% CI: -22 to -12) and LDL-C (MD = -9 mg/dL; 95% CI: -13 to -6) compared to placebo in individuals with elevated baseline levels. No significant effect was observed on HDL-C or triglycerides.

Discussion: The findings indicate that garlic supplementation provides a modest but statistically significant benefit in reducing total cholesterol and LDL-C. This effect could be clinically relevant as part of a comprehensive lifestyle and dietary approach to cardiovascular risk reduction. The effect appears to be dependent on the duration of treatment.

Conclusion: Evidence from trials before 2020 suggests that garlic supplements can be an effective complementary treatment for mild hypercholesterolemia.