Inhibiting progression of coronary calcification using Aged Garlic Extract in patients receiving statin therapy: a preliminary study

Background. Aged Garlic Extract (AGE) reduces multiple cardiovascular risk factors, including blood pressure, cholesterol, platelet aggregation and adhesion, while stimulating nitric oxide generation in endothelial cells. However, no study has evaluated the ability of AGE to inhibit vascular calcification, a marker of plaque formation in human coronary arteries. Objective. To assess the efficacy of Aged Garlic Extract (AGE) on changing the rate of atherosclerosis progression as compared to placebo. Design. A placebo-controlled, double-blind, randomized pilot study to determine whether the atherosclerotic plaque burden detected by electron beam tomography (EBT) will change at a different rate under the influence of AGE as compared to placebo. Twenty-three patients were enrolled, and 19 patients completed the study protocol. AGE 4 ml or the equivalent amount of placebo was given to subjects. Duration of the study was 1 year. S-allylcysteine (SAC), one of the active compound of AGE, was measured in the blood as a compliance marker. Results. The mean change of the calcium score (volumetric method) for the AGE group (n = 9) was 7.5 ± 9.4% over 1 year. The placebo group (n = 10) demonstrated an average increase in calcium scores of 22.2 ± 18.5%, significantly greater than the treated cohort (P = 0.046). There were no significant differences in individual cholesterol parameters or C reactive protein between the groups. In patients randomized to AGE, there was a nonsignificant trend for improving cholesterol/high-density lipoprotein ratio (P = 0.07) and homocysteine level (P = 0.08). Conclusions. This small pilot study indicates the potential ability of AGE to inhibit the rate of progression of coronary calcification, as compared to placebo over 1 year. Should these findings be extended and confirmed in larger studies, garlic may prove useful for patients who are at high risk of future cardiovascular events.