Effect of Garlic on Blood Pressure: A Meta‐Analysis

Garlic supplements are thought to reduce blood pressure ( BP ). The authors performed a meta‐analysis to investigate garlic's effect on BP . Ovid Medline, Cochrane Library, and PubMed (1946 to November 2013) were used to search for randomized controlled trials. Seventeen trials were included. Pooled analysis showed that garlic intake caused a 3.75‐mm Hg reduction (95% confidence interval [ CI ], −5.04 to −2.45, I 2 =30.7%; P <.001) in systolic BP and a 3.39‐mm Hg reduction (95% CI , −4.14 to −2.65, I 2 =67%; P <.001) in diastolic BP compared with controls. Meta‐analysis of subgroups showed a significant reduction in systolic BP in hypertensive (−4.4 mm Hg; 95% CI , −7.37 to −1.42, I 2 =0.0%; P =.004) but not normotensive patients. No significant reduction in diastolic BP was seen. After sensitivity analysis, heterogeneity disappeared and significant diastolic BP reduction (−2.68 mm Hg, 95% CI , −4.93 to −0.42, I 2 =0.0%; P =.020) was shown in hypertensive patients. This meta‐analysis suggests that garlic supplements are superior to controls (placebo in most trails) in reducing BP , especially in hypertensive patients.