Flavonoid-rich foods and drinks may lower a woman's risk of developing ovarian cancer, according to a new study.

Dr. Margaret A. Gates, of Brigham and Women's Hospital and Harvard Medical School, in Boston, Massachusetts says: "flavonoids found in vegetables, fruits, beans and tea may be significantly beneficial."

Flavonoids are a large family of antioxidant compounds known as phytochemicals. They are part of a plant's natural defense system that helps the plant fight off disease and infection.

The study suggests flavonoids could help prevent a variety of diseases in humans -- including cancer -- by protecting cells from DNA damage. Scientists believe some flavonoids may also deter cancer development by helping to regulate cell growth and fight inflammation or by changing hormone levels.

In a study that compared flavonoid intake among women with and without ovarian cancer, women reporting the highest flavonoid intake had a "borderline significant decrease" in ovarian cancer risk over women reporting the lowest flavonoid intake, Gates and her associates report in the International Journal of Cancer.

"These results are promising," Gates told Reuters Health, "but more research is needed to confirm this association."

The researchers assessed the foods commonly eaten over a one-week period by 1,141 women with ovarian cancer and 1,183 women without.

The women, 51 years old on average, had similar characteristics except those with ovarian cancer reported more known risk factors for the disease and had slightly greater body mass and daily calorie intake. By contrast, the disease-free "controls" had a slightly healthier overall diet.

From the food data, Gate's group calculated the women's intake of 5 common flavonoids -- myricetin, kaempferol, quercetin, luteolin, and apigenin -- frequently obtained by drinking tea or red wine, or eating apples, romaine or leaf lettuce, kale, blueberries, oranges, celery, or tomato sauce.

The investigators found no association between total flavonoid intake and ovarian cancer risk in analyses that allowed for factors potentially associated with ovarian cancer risk such as age, oral contraceptive use, childbirth, breastfeeding, history of tubal ligation, and physical activity.

Only apigenin intake was associated with a suggestive decrease in ovarian cancer risk.

These findings, in concert with results of other studies suggesting an inverse association between intake of certain flavonoids and risk of ovarian cancer, highlight the need for further research, Gates and her colleagues suggest.

(Agencies via Xinhua April 24, 2009)