Effects of aged black garlic (ABG10+®) on lipoprotein subclass composition in Grade I hypertension: a randomized, triple-blind controlled trial with sex-stratified sequential allocation.

BACKGROUND: Aged black garlic (ABG) is rich in organosulfur compounds such as S-allyl-cysteine (SAC) and may influence lipid metabolism, although evidence from controlled trials remains limited. The aim of this study was to evaluate the impact of a low-dose SAC-optimized ABG on blood lipid profiles in Grade I hypertensive individuals. METHODS: A randomized, triple-blind, placebo-controlled trial with systematic sex-stratified sequential allocation was conducted with 75 Grade I hypertensive participants receiving either 250 mg of ABG or a placebo daily for 12 weeks. Plasma lipoproteins and subclass composition were quantified by NMR spectroscopy, and metabolic clusters were explored using k-means and PLS-DA. RESULTS: ABG supplementation did not produce statistically significant changes in any conventional lipid marker (total cholesterol, LDL-C, HDL-C, or triglycerides). In secondary exploratory analyses of NMR-derived lipoprotein subclasses, nominally significant differences were observed: ABG was associated with a reduction in the total number of particles and HDL particles. Detailed analysis of XXL-VLDL particles showed a decrease in the percentage of free and esterified cholesterol alongside an increase in triglyceride percentage. Large HDL particles showed compositional remodeling characterized by an increase in phospholipid content and a decrease in triglyceride percentage. In exploratory cluster analyses, participants with a more adverse baseline metabolic profile showed a nominally significant reduction in total triglycerides and VLDL-lipid content after ABG intake. CONCLUSION: Low-dose ABG supplementation did not significantly modify conventional lipid markers in Grade I hypertensive individuals. However, secondary exploratory NMR-based analyses suggest that ABG may induce compositional remodeling of lipoprotein subclasses-particularly reducing the cholesterol load in large VLDL particles and enhancing HDL phospholipid content-especially in individuals with a more adverse baseline metabolic profile. These findings are hypothesis-generating and require confirmation in adequately powered trials with pre-specified NMR endpoints. CLINICAL TRIAL REGISTRATION: identifier: NCT04915053.