The next time you use garlic for its renowned antibacterial effects, consider fresh garlic instead of those bottles of chopped garlic. Researchers in Japan report that fresh garlic maintains higher levels of a key healthy ingredient than preserved versions and may be better for you. Their study is scheduled for the June 25 issue of ACS' Journal of Agricultural and Food Chemistry.
In the new study, Toyohiko Ariga and colleagues point out that allicin is one of the main active ingredients in garlic. Other studies have shown that allicin has beneficial effects in preventing blood clots, cancer, and bacterial infection.
Although commercially bottled garlic is often stored in oil or water, researchers did not know how various storage and preservation methods affect levels of allicin, which is fragile and disappears quickly.
To find out, Ariga's group compared allicin levels in extracts of fresh garlic after 1-2 weeks of storage in water, alcohol, and vegetable oil. Garlic stored in water at room temperature lost about half its allicin in 6 days and garlic in vegetable oil lost half its allicin in less than an hour.
The garlic lost its antibacterial action as allicin broke down. However, allicin broke down into materials that still are believed to have some anticancer and anti-blood clot effects.