Flavonoids: Another Cancer Fighter ?

Compounds called flavonoids, found in many fruits and vegetables, may be yet another piece in the cancer prevention puzzle, Finnish researchers suggest in the August 1 American Journal of Epidemiology. Like the better-known cancer-fighting candidates vitamin C and beta-carotene, flavonoids are antioxidants, which are believed to counteract the damage that free radicals wreak on cells.

In a 24-year study of nearly 10,000 men and women, the researchers found that those who got the most flavonoids from foods were 20 percent less likely to develop any form of cancer than those whose diets contained the smallest amounts. For lung cancer specifically, the group with the highest flavonoid intake had a 46 percent lower risk.

Flavonoids are found in a variety of fruits and vegetables, most notably
Broccoli
Carrots
Citrus fruits
Eggplant
Peppers
Soybeans
Squash
Tomatoes
Apples
Onions
Tea
Red Wine

. In the Finnish study, apples and onions constituted the biggest source. Regular apple-eaters had the lowest risk of lung cancer overall—68 percent lower than people who ate the fruit infrequently. Other major sources of flavonoids include tea and red wine.

Although studies consistently show that people whose diets include large amounts of fruits and vegetables have a lower risk of cancer, trials of specific nutrients have been less conclusive. Two large studies of beta-carotene, for example, showed that people taking the antioxidant as a supplement pill actually had a higher risk of lung cancer; other studies found no added benefit or risk. It's likely, the Finnish researchers say, that a variety of nutrients—including flavonoids—are involved in the anti-cancer effect.

This study adds to the evidence that a combination of antioxidants are needed for a complete, healthy diet and that it's best to get these nutrients from foods rather than supplements

There aren't likely to be any short cuts to getting around the need for a diet rich in plant-based foods that are high in fiber—and in compounds like flavonoids—as well as low in fat.