And a Dutch study found that those who ate half an onion a day had half the risk of stomach cancer, ascribing this to an antioxidant called quercetin, found in onions, especially red and yellow onions. Which I can see I'm going to have to discuss. The active ingredients in onions and garlic are mostly sulfur compounds, to which our noses are quite sensitive. Odorless garlic preparations, many authorities suggest, are useless garlic preparations. But then, they all disagree about whether you should eat raw or cooked onions, and whether garlic should be eaten raw, cooked, fresh, aged or in a capsule.
Many sources recommend chewing parsley after eating garlic or onions, to freshen the breath.
I suspect it's propaganda from the Parsley Board. A recent German study that claimed powerful garlic pills could not only reduce the rate of plaque formation in arteries, but actually make existing plaque go away, has been criticized on several counts. Another complaint is that the statistical analysis ignored the fact that many patients quit the study because they couldn't stand the ferocious reek of the high-dose pills. While onions and garlic may not be the answer to every medical problem, they are beneficial as well as enjoyable, providing you stay away from zealots with blenders. The only things to watch out for in your pursuit of the allium vegetables are people who are just trying to fortify you for building pyramids, defending Shiloh or conquering Asia Minor.