Evidence Level
Aged garlic extract is one of the better-studied cardiovascular supplements. Ried et al. have published multiple meta-analyses confirming its blood pressure-lowering effects, with the most recent (2020) showing an 8.3 mmHg reduction in systolic blood pressure across pooled RCT data — clinically meaningful and comparable to some first-line antihypertensives. For cholesterol, a 2016 double-blind RCT by Ried et al. in the Journal of Nutrition found 2400mg/day of aged garlic extract reduced total cholesterol, LDL, and coronary artery calcium progression in metabolic syndrome patients. The unique advantage of aged garlic over raw garlic supplements is the conversion of unstable allicin into stable S-allyl cysteine (SAC), which has 98% oral bioavailability — far higher than allicin, which degrades rapidly in the GI tract. For immune function, Nantz et al. (2012) conducted a 90-day RCT showing that aged garlic extract enhanced NK cell and gamma-delta T-cell proliferation and reduced the severity of cold and flu symptoms by 21%.