Cancer Prevention

Onion extracts, rich in a variety of sulfides, provide some protection against tumor growth. In central Georgia where Vidalia onions are grown, mortality rates from stomach cancer are about one-half the average level for the United States. Studies in Greece have shown a high consumption of onions, garlic and other allium herbs to be protective against stomach cancer. 

Chinese with the highest intake of onions, garlic, and other Allium vegetables have a risk of stomach cancer 40 percent less than those with the lowest intake. Elderly Dutch men and women with the highest onion consumption (at least one-half onion/day) had one-half the level of stomach cancer compared with those consuming no onions at all. 

Western Yellow, New York Bold, and Northern Red onions have the richest concentration of flavonoids and phenolics, providing them with the greatest antioxidant and anti-proliferative activity of 10 onions tested. The mild-tasting Western White and Vidalia onions had the lowest antioxidant content and lowest anti-proliferative activity. The consumer trend to increasingly purchase the less pungent, milder onion varieties may not be the best, since the onions with a stronger flavor and higher astringency appear to have superior health-promoting properties.