Two micronutrients contained in many fruits and vegetables, called carotenoids and lycopene, may cut the risk of ovarian cancer.

In a recent study, the more that women ate foods rich in these substances, the lower their risk of ovarian cancer, according to a report in the International Journal of Cancer (Vol. 94: 128-134).

"Ovarian cancer is often diagnosed at late stages, so if we can learn how to reduce the risk of getting this often-fatal cancer, that's a valuable thing," says Marji McCullough, ScD, RD, a nutritional epidemiologist with the American Cancer Society.

In an study involving 549 women with ovarian cancer and 516 "controls" — cancer-free women with similar characteristics to the women with the disease — researchers in Massachusetts and New Hampshire looked for specific foods that distinguished women without ovarian cancer from those with ovarian cancer.

In the final analysis, raw carrots and tomato sauce stood out, says Daniel W. Cramer, MD, professor of obstetrics and gynecology at Harvard Medical School, and at Brigham and Women's Hospital.

Women who said they ate two or more one-half cup servings per week had a 40% decrease in risk for ovarian cancer, compared to women who reported eating tomato sauce less than once a month.

And women who ate five or more servings (four cut sticks) of raw carrots per week had a 54% decrease in their risk for ovarian cancer, compared to women who reported eating raw carrots less than once a month,.

So, fresh tomatoes aren't as helpful as simmered, as in spaghetti sauce?

"I certainly wouldn't discourage any woman from eating raw tomatoes," Cramer says. "But as is true from other studies, it seems to be that heat and a little bit of oil brings lycopene out."

Carotenoids are yellow, orange, or red pigments, found in many fruits and vegetables. Carotenoids include substances such as alpha- and beta-carotene that the body converts to A vitamin, says the ACS's McCullough.

They also include other compounds with potent antioxidant properties, such as lycopene — an extra-strong antioxidant found in tomatoes and tomato products such as marinara sauce.

As the study notes, A vitamin may be involved in apoptosis. Apoptosis, or controlled cell death, is a mechanism for limiting growth of tumors, says Cramer.

But the antioxidant properties of the carotenoids may also be important.

"Many people believe there can be damage to DNA from oxidants in the blood," Cramer says. "And having a high level of the antioxidant carotenoids can prevent damage to the DNA."

Damaged DNA can lead to cancer, he says, either because genes that ordinarily suppress tumors are inactivated, or because the changes can cause overproduction of oncogenes, or tumor-causing genes. A cell's ability to change its function is affected by A vitamin.

While the study doesn't prove that you can prevent ovarian cancer with these foods, Cramer says, eating raw carrots and tomato sauce "are both easy-to-do lifestyle changes, and health habits that may be beneficial to you in any case."

Scientific evidence is mounting, as Cramer notes in the paper, that eating foods high in certain carotenoids may decrease the risk for a variety of cancers, including prostate, cervix, and breast.

"I have a definite reluctance to say, 'Get these products through supplements,' " Cramer says of alpha- and beta-carotene, "because of several clinical trials that had the absolute opposite conclusion of what one would expect."

In these studies, vitamin supplements actually increased the rates of cancer. A daily multivitamin is fine, he says, "But don't say, 'I took a multivitamin, therefore, I don't need that serving of carrots.'"

The American Cancer Society recommends a diet high in plant foods, especially fruits and vegetables, says McCullough, and the authors' take-home message is consistent with that: eat foods rich in these nutrients.

One cannot live on tomato sauce and raw carrots alone. A cornucopia of foods are rich sources of carotenoids, including spinach, yams, corn, broccoli, cantaloupe, oranges, collard greens, vegetable soup, steamed carrots, pizza sauce, and tomatoes.