Garlic-derived SAC — The Cardioprotective Antioxidant

S-allyl cysteine (SAC) is a water-soluble organosulfur compound formed during the aging process of garlic. It acts as a potent antioxidant by directly scavenging reactive oxygen species (ROS) and upregulating endogenous antioxidant enzymes such as catalase, superoxide dismutase (SOD), and glutathione peroxidase. SAC enhances nitric oxide (NO) bioavailability by increasing endothelial nitric oxide synthase (eNOS) activity, leading to vasodilation and reduced arterial stiffness. It also exerts anti-inflammatory effects by inhibiting the NF-κB pathway and reducing the expression of pro-inflammatory cytokines.

Multiple randomized controlled trials have demonstrated that aged garlic extract (AGE), standardized for S-allyl cysteine, significantly reduces systolic and diastolic blood pressure in patients with uncontrolled hypertension. Trials also show improvements in arterial stiffness, endothelial function, and reductions in oxidized LDL cholesterol. The strongest evidence supports its use as an adjunct therapy for cardiovascular risk reduction.

Typical doses of aged garlic extract (AGE) range from 600 to 2,400 mg per day, standardized to provide 1.2 to 2.4 mg of S-allyl cysteine (SAC). It is usually taken in divided doses with meals. Higher doses (up to 2.4 mg SAC) have been used in blood pressure trials.

Generally well tolerated with a high safety profile. Mild gastrointestinal side effects, such as bloating or upset stomach, may occur. Due to its mild antiplatelet properties, caution is advised when combining with blood thinners (e.g., warfarin, aspirin) or prior to surgery. It may also interact with certain HIV medications and antihypertensive drugs, potentially causing additive blood pressure-lowering effects.

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