Educational only — not medical advice.
Garlic contains allicin, a sulfur-based compound that breaks down into several metabolites when garlic is crushed or chewed. Research published in the Proceedings of the National Academy of Sciences (online Oct. 19, 2007; 10.1073/pnas.0705710104) shows that these metabolites help support cardiovascular health by stimulating the production of hydrogen sulfide (H₂S) — a signaling molecule that relaxes blood vessels.
In the study, researchers combined garlic extract with red blood cells. Allicin rapidly broke down into organosulfur compounds, including diallyl sulfide, diallyl disulfide, diallyl trisulfide, and ajoene. When exposed to these compounds, the red blood cells released measurable amounts of H₂S.
To test physiological effects, the researchers applied the treated red blood cells to muscular rings taken from the aortas of rats. The result was clear: the vessels relaxed in a dose-dependent manner. The higher the garlic concentration, the greater the relaxation response.
This mechanism provides a biochemical explanation for garlic’s traditional use in supporting healthy blood pressure and vascular function.
