Allicin is a sulfur compound in garlic that is responsible for its strong odor. When a garlic plant is attacked by pests or microbial pathogens in the soil, it produces allicin by an enzymatic reaction.
Allicin possesses antioxidant activity and antibacterial activities. Research has shown that consuming garlic can help lower LDL (“bad”) cholesterol and increase HDL (“good”) cholesterol, which helps reduce the risk of heart disease and strokes, according to Allicin Facts. Garlic/allicin activities may also have positive effects on preventing the common cold, reducing the risk of cancer, and fighting microbial diseases.