Most of us know garlic tastes good. Now, a research team from Queen's University, Kingston, Ontario, Canada, has discovered why garlic is good for us.
Prior research has revealed that the organic compound, allicin—which gives the pungent vegetable its aroma and flavor—acts as an antioxidant. But, until now, it hasn’t been clear how allicin works.
“We didn’t understand how garlic could contain such an efficient antioxidant, since it didn’t have a substantial amount of the types of compounds usually responsible for high antioxidant activity in plants, such as the flavanoids found in green tea or grapes,” says Dr. Pratt, Canada Research Chair in Free Radical Chemistry. “If allicin was indeed responsible for this activity in garlic, we wanted to find out how it worked.”
Through experiments with synthetically-produced allicin, the research team found that sulfenic acid produced when the compound decomposes rapidly reacts with radicals.
“While garlic has been used as an herbal medicine for centuries and there are many garlic supplements on the market, until now there has been no convincing explanation as to why it is beneficial,” says Dr. Pratt. “I think we have taken the first step in uncovering a fundamental chemical mechanism which may explain garlic’s medicinal benefits.”
Along with onions, leeks and shallots, garlic is a species in the family Alliaceae. All of these other plants contain a compound that is very similar to allicin, but they do not have the same medicinal properties. Dr. Pratt and his colleagues believe that this is due to a slower rate of decomposition of allicin in the other vegetables, which leads to a lower level of sulfenic acid available to react as antioxidants with radicals.