allicin

Allicin, also known as diallyl thiosulfinate, is an organosulfur compound produced when garlic is damaged. It forms from the precursor alliin by the action of the enzyme alliinase, a reaction that occurs when garlic tissues are crushed or chopped. Allicin is relatively unstable and rapidly rearranges into a mixture of sulfur-containing compounds, including diallyl disulfide and ajoene, which contribute to garlic’s characteristic aroma as well as its biological activity.

Chemically, allicin has the formula C6H10OS2 and features a thiosulfinate group flanked by two allyl groups. This arrangement makes allicin highly reactive with thiol groups in proteins, a property linked to its proposed antimicrobial effects. In vitro studies have reported activity against a range of bacteria, fungi, and some viruses, and the compound is also investigated for anti-inflammatory and antioxidant effects in various models. However, translating these findings to meaningful health benefits in humans remains uncertain.

Pharmacokinetics and metabolism reflect its instability. After ingestion, intact allicin is short-lived, and systemic exposure is limited; metabolites such as allyl methyl sulfide can appear in breath and urine, contributing to the familiar garlic odor.

Clinical evidence for allicin’s health benefits is mixed. While some small studies of garlic preparations suggest cardiovascular or lipid effects, robust, high-quality human data specifically attributing benefits to allicin are lacking. Safety in culinary use is generally good; higher doses can cause gastrointestinal upset or irritation, and interactions with anticoagulant or antiplatelet medications are possible.

storage and handling: Allicin degrades rapidly; fresh preparation of garlic optimizes formation, while heating and prolonged storage reduce its presence.