Black garlic, produced by fermenting raw garlic under controlled heat and humidity, has become popular due to its enhanced antioxidant properties and milder flavor. There is some scientific interest in using black garlic for cardiovascular health, including arteriosclerosis (the thickening and hardening of arterial walls). Preclinical studies, mostly in animal models and in vitro, have suggested that black garlic and its compounds (such as S-allyl cysteine and other organosulfur compounds) may reduce oxidative stress, inhibit inflammation, and improve lipid profiles—all factors involved in the development of arteriosclerosis.

For example, several studies in rats have shown that black garlic extract can lower cholesterol levels, decrease arterial plaque formation, and improve markers of vascular function. The antioxidant activity of black garlic is generally higher than that of fresh garlic, which may contribute to its protective effects against endothelial dysfunction and lipid peroxidation in blood vessels. A few small human clinical trials have indicated that black garlic supplementation might improve cholesterol levels and arterial stiffness, but these studies are limited by sample size and duration.

Overall, while there is preliminary scientific evidence suggesting black garlic may have benefits for arteriosclerosis, the quality and quantity of human clinical data are still insufficient for strong recommendations. Thus, its use is justified by early-stage scientific findings rather than longstanding tradition or robust clinical proof.