Aged garlic extract improves endothelial function in men with coronary artery disease

Endothelium-dependent vasodilation is impaired and predicts the risk of a coronary event in patients with coronary artery disease (CAD). Oxidant stress and increased systemic inflammation may contribute to this endothelial dysfunction. Aged garlic extract (AGE) contains antioxidant compounds and increases nitric oxide production and decreases the output of inflammatory cytokines from cultured cells. The aim of this study was to test the effect of treatment with AGE on brachial artery flow mediated endothelium-dependent dilation (FMD) and circulating markers of oxidative stress and systemic inflammation. The trial included 15 men with angiographically proven CAD in a randomized, placebo-controlled, cross-over design with 2-week treatment and washout periods. During AGE supplementation, FMD increased (44%) significantly (p = 0.04) from the baseline and mainly in men with lower baseline FMD. Levels of FMD at the end of AGE treatment were significantly (p = 0.03) higher compared with the corresponding levels at the end of placebo treatment when the variation in baseline body weight was taken into account. Markers of oxidant stress (plasma oxidized low density lipoprotein and peroxides), systemic inflammation (plasma C-reactive protein ad interleukin-6) and endothelial activation (VCAM-1) did not change significantly during the study. These data suggest that short-term treatment with AGE may improve impaired endothelial function in men with CAD treated with aspirin and a statin. Whether improvement in endothelial function decreases the risk of future cardiovascular events remains to be determined.