Science / Medicine : Onion Family Vegetables May Help Prevent Stomach Cancer, Study Says

A diet rich in onions, garlic, leeks, chives and scallions may give some protection against stomach cancer, according to a National Cancer Institute study conducted in China.

In a study that focused on the differences in diet between stomach cancer patients and those without cancer in Linqu, China, researchers found that “allium vegetables (such as onions and garlic) can significantly reduce the risk of stomach cancer.”

The study, published this week in the Journal of the National Cancer Institute, used questionnaires to compare the dietary habits of 685 patients with stomach cancer and 1,131 other people, matched by age, gender, occupation and education, who had no diagnosed cancer.

People in the control, or cancer-free, group consumed from 25 to more than 50 pounds of allium vegetables a year. The cancer patients ate less than 25 pounds of the vegetables.

The study also found that the risk of cancer of the stomach declined as the habitual consumption of such vegetables increased. In other words, the more onions and garlic you eat over a lifetime, the less your chances of stomach cancer.

“Persons in Linqu tended to be exposed to mild doses of allium vegetables over long periods, likely beginning in childhood,” the study said. “Our study suggests that all or part of such exposure has resulted in a reduction in stomach cancer risk starting at an early age . . . and continuing throughout life.”

The anti-cancer effects of onion-like root vegetables have been suggested in studies dating back to the 1950s. A 1979 study, for instance, found a reduced incidence of stomach cancer among residents of a Georgia county famous for growing onions. A study in Greece showed that gastric cancer patients usually ate fewer fresh vegetables, including onions, than those who were cancer-free.

“Several experimental studies have suggested that compounds in allium vegetables can protect against cancer in laboratory animals,” the National Cancer Institute Journal study said. It said that chemical compounds extracted from onions and garlic have shown in a variety of studies to reduce, alter or prevent cancers in laboratory rats, mice and hamsters.