EFFECT OF GARLIC ON TOTAL SERUM-CHOLESTEROL - A METAANALYSIS

Objective: To assess the size and consistency of garlic's effect on to tal serum cholesterol in persons with cholesterol levels greater than 5.17 mmol/L (200 mg/dL). Data Sources: Clinical trials were identified by a computerized literature search of MEDLINE and by an assessment o f the bibliographies of published studies and reviews. Study Selection : Trials were selected if they were randomized and placebo-controlled and if at least 75% of their patients had cholesterol levels greater t han 5.17 mmol/L (200 mg/dL). Studies were excluded if they did not pro vide enough data to compute effect size. Five of 28 studies were selec ted for review. Data Extraction: Details of study design, patient char acteristics, interventions, duration of therapy, and cholesterol measu rements were extracted by one author and were verified by another. Dat a Synthesis: Study quality was evaluated by multiple reviewers using a closed-ended questionnaire. Patients treated with garlic consistently showed a greater decrease in total cholesterol levels compared with t hose receiving placebo. Meta-analysis of homogeneous trials estimated a net cholesterol decrease attributable to garlic of 0.59 mmol/L (95% CI, 0.44 to 0.74) (23 mg/dL [CI, 17 to 29]) (P < 0.001). Conclusions: Meta-analysis of the controlled trials of garlic to reduce hypercholes terolemia showed a significant reduction in total cholesterol levels. The best available evidence suggests that garlic, in an amount approxi mating one half to one clove per day, decreased total serum cholestero l levels by about 9% in the groups of patients studied.