No one knows yet how many daily servings of onions youd have to eat to maximize protection against cancer, but our study suggests that people who are more health-conscious might want to go with the stronger onions rather than the mild ones, says study leader Rui Hai Liu, M.D., Ph.D., a chemist with Cornells Department of Food Science in Ithaca, N.Y.
Researchers have known for some time that onions may help fight cancer, but the current study is believed to be the first to compare cancer-fighting abilities among commonly consumed onion varieties. The new study will appear in the Nov. 3 print issue of the Journal of Agricultural and Food Chemistry, a peer-reviewed journal of the American Chemical Society, the worlds largest scientific society.
Liu and his associates analyzed 10 common onion varieties and shallots for total antioxidant activity and their ability to fight the growth of cancer in human cell lines. Although shallots resemble onions, they are actually a separate, distinctive species. Fresh, uncooked samples were used, with extracts taken from the bulbs with the outer skin removed.
Shallots and onion varieties with the strongest flavor Western Yellow, New York Bold and Northern Red had the highest total antioxidant activity, an indication that they may have a stronger ability to destroy charged molecules called free radicals, an excess of which are thought to increase the risk of disease, particularly cancer, the researcher says.
Onion varieties with the mildest flavor Empire Sweet, Western White, Peruvian Sweet, Mexico, Texas 1015,
Contact: Michael Bernstein
American Chemical Society