It is derived from a sulfur compound known as alliin, which itself has no healing properties. Once allicin has formed, it is highly unstable, breaking down in a few days. It is essential therefore, that strict precautions be taken during the manufacturing process to ensure alliin is not converted to allicin. Since it is a highly stable compound, the presence of alliin in a garlic formula is an excellent marker for measuring product quality. Garlic supplements standardized for alliin content also effectively reduce blood pressure in people suffering from hypertension.
Several studies show that garlic standardized for alliin content inhibits platelet aggregation.
Since the 1940s, many studies have concluded that garlic juice and allicin inhibit the growth of Staphylococcus, Streptococcus, Bacillus, Brucella and Vibrio species. 5 Recent studies have confirmed allicin's efficacy against many bacteria, including Staphylococcus aureus, Streptococcus, Escherichia coli, Proteus vulgaris, Salmonella enteriditis, Citrobacter species, Klebsiella pneumoniae and mycobacteria. 6,7 These recent studies compared the efficacy of garlic with that of commonly used antibiotics including penicillin, streptomycin, chloramphenicol, erythromycin and tetracycline. In addition to confirming garlic's antibiotic effects, the studies also demonstrated the herb's ability to kill bacteria that had become resistant to one or more of the antibiotics used. In animal and test-tube studies, garlic was shown to be more effective than seven antifungals commonly used for yeast infection, including prescription nystatin.