The Effect of Aged Garlic Supplementation on Blood Pressure and Lipid Profile: A Dose-Response Grade-Assessed Systematic Review and Meta-Analysis of Randomized Controlled Trials

Numerous clinical trials have examined the effects of aged garlic (AG) on metabolic factors, yielding inconsistent results. This systematic review and meta-analysis aimed to evaluate the impact of aged garlic on blood pressure (BP) and lipid profiles (LP). A comprehensive search was conducted across Scopus, PubMed, Medline via Ovid, ISI Web of Science, and Google Scholar until May 2024. We included clinical trials that assessed various forms of aged garlic as an intervention on systolic and diastolic blood pressure (SBP and DBP), total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL). Weighted mean differences (WMD) and 95% confidence intervals (CI) were calculated using a random-effects model. Nineteen trials were included in this analysis. AG consumption significantly reduced SBP (WMD: -2.49 mmHg; 95% CI: -4.02 to -0.95; I-2 = 29.76%) and LDL (WMD: -4.41 mg/dL; 95% CI: -8.28 to -0.54; I-2 = 55.78%). However, it did not significantly affect DBP and HDL, although the effect on TC approached significance (WMD: -4.74 mg/dL; 95% CI: -9.49 to 0.01; I-2 = 74.84%). Subgroup analyses indicated that AG significantly affected SBP and TG in participants with cardiovascular diseases (CVDs), while it also considerably impacted DBP in patients with hypercholesterolemia. Aged garlic may be a beneficial complementary approach for reducing BP and lipid levels in specific populations. Further high-quality trials are needed to confirm these findings.