Alliin is a sulfur-containing compound found in garlic (Allium sativum) and is best known as the precursor to allicin, which forms when garlic is crushed or chopped. While garlic has been used traditionally for cardiovascular health, including arteriosclerosis (hardening of the arteries), the specific scientific evidence for alliin itself is limited but emerging.

Several preclinical and a few human studies suggest that alliin and related garlic compounds may have beneficial effects on cardiovascular health by reducing lipid levels, inhibiting platelet aggregation, lowering blood pressure, and acting as antioxidants. These mechanisms are relevant to arteriosclerosis, which involves lipid accumulation, inflammation, and oxidative stress in arterial walls. For example, some animal models have demonstrated that alliin administration can reduce the progression of arterial plaque and improve endothelial function. A few small human studies have reported improvements in blood lipid profiles and markers of oxidative stress with garlic supplements high in alliin.

However, the direct clinical evidence specifically linking alliin (not just general garlic extracts or allicin) to the treatment or prevention of arteriosclerosis in humans is currently limited and not robust. Most evidence is indirect or from broader garlic extract studies rather than purified alliin. As such, while there is some scientific rationale and early supportive data, the overall quality and quantity of evidence supporting alliin’s use for arteriosclerosis is modest.