Christopher Hom, Yanting Luo and Matthew Jay Budoff
Background: Aged Garlic Extract (AGE) has been shown to lower LDL, reduce the progression of coronary atherosclerosis, improve vascular function, and have a favorable effect on oxidative biomarkers. Since AGE has been shown to have several potential anti-atherosclerotic properties, including stimulation of microcirculation in peripheral arteries, it was chosen as the agent of study to evaluate its ability to inhibit progression of coronary atherosclerosis.
Objective: No study of sufficient power to date has evaluated the ability of AGE to inhibit vascular calcification, a marker of plaque formation in human coronary arteries. We sought to evaluate the ability of AGE to inhibit coronary artery calcium (CAC).
Methods: Four placebo-controlled, double-blind, randomized studies were pooled to determine whether the atherosclerotic plaque burden detected by CAC will change at a different rate under the influence of AGE as compared to placebo. 210 patients were enrolled, and 182 completed the study protocol. All participants underwent CAC scanning at baseline and at 12 months. A two-sample median test was used to compare medians of CAC progression between the garlic- and placebo-treated groups. CAC progression was also categorized into three groups (<15%, 15-20%, and >20%) prior to adjustment for age and gender.
Results: At 1 year, median CAC progression was significantly lower in the pooled AGE group (10.8, 95% Confidence Interval (CI) 0.0-30.7, n=106) than the placebo group (18.3, 95% CI 3.1-34.0, n=103; P=0.0385). There were no significant differences in individual serum cholesterol parameters or serum C-reactive protein levels between the groups. Further, after adjustment for age and gender, AGE was associated with a 1.78 fold (95% CI 0.320-0.990, P=0.046) reduction in CAC progression compared with placebo.
Conclusions: This pooled study indicates the ability of AGE to inhibit the rate of progression of coronary calcification, as compared to placebo, over 1 year independent of statin therapy or gender.