Plant-based flavonoid may cut ovarian cancer risk

Women who eat greater amounts of plant-based foods and drinks with the naturally occurring flavonoid, apigenin, may have a decreased risk for ovarian cancer, study findings suggest.

Apigenin, found in celery, parsley, red wine, tomato sauce, and other plant-based foods may be "particularly beneficial," said Dr. Margaret A. Gates, of Brigham and Women's Hospital and Harvard Medical School, in Boston, Massachusetts.

Flavanoids are compounds with antioxidant properties that protect cells against damage by oxygen molecules. In a study that compared flavonoid intake among women with and without ovarian cancer, women reporting the highest apigenin intake had a "borderline significant decrease" in ovarian cancer risk over women reporting the lowest apigenin 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, as noted, 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.

SOURCE: International Journal of Cancer, April 2009.