Eating an apple a day may help guard against breast cancer (search), say Cornell University researchers.

If you’re going to act on the finding -- which comes from lab tests on rats -- grab an apple instead of reaching for vitamins and supplements from bottles, suggest the researchers.

Studies have consistently shown that diets high in fruits and vegetables are associated with a reduced risk of chronic diseases.

The credit probably goes to disease-fighting antioxidants (search) from plants known as phytochemicals (search), they write. Fruits, vegetables, whole grains, and other plant foods are packed with antioxidants. The chemicals have been widely studied for their benefits against heart disease, cancer, and preventing diseases such as cataracts, age-related macular degeneration, and diabetes, say the researchers.

Whole Foods Trump Supplements

Antioxidants are good for you, but does it matter if it comes from a pill or from produce?

Yes, say the researchers. Antioxidants in foods work together and their combined effect is greatest, they explain.

“No single antioxidant can replace the combination of natural phytochemicals in fruits and vegetables in achieving ultimate health benefits,” write the researchers. “The pure compounds either lose their bioactivities in isolation or may not behave the same way as the compound in complex whole foods.

“Our findings suggest that consumers may gain more significant health benefits from including whole foods in their balanced diet than from more expensive dietary supplements, which do not contain the same array of balanced, complex components.”

Testing the Theory

The researchers gave rats a chemical to induce breast cancer. The scientists also brewed extracts made from Red Delicious apples, which are commonly found in grocery stores across America.

The researchers tested three doses of the extract. For humans, the doses equaled eating one, three, or six apples per day.

After 24 weeks, breast tumor rates were 17 percent lower in the rats receiving the low dose of the apple extract, 39 percent lower with the medium dose, and 44 percent lower with the high dose.

The number of tumors also dropped 25 percent with the low dose, 25 percent with the medium dose, and 61 percent with the high dose.

Tumors also took longer to show up in the rats receiving the apple extract. The tumors appeared within 11 weeks in rats that didn’t get the extract. But tumors appeared by 12 weeks in rats on the low and medium doses, and by 13 weeks in those on the high dose.

The extracts “effectively inhibited” breast cancer in rats, write food science professor Rui Hai Liu, PhD, MD, MS, and colleagues. “Thus, consumption of apples may be an effective strategy for cancer protection,” says their study.

Of course, rats aren’t people. They didn’t have some of our bad health habits, such as smoking or obesity. No one can promise that apples will keep humans free of breast cancer. But since many Americans don’t eat enough produce, eating more apples might be a good idea.

The study will appear in the March 23 edition of the Journal of Agricultural and Food Chemistry.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Liu, R. Journal of Agricultural and Food Chemistry, March 23, 2005; vol 53. News release, Cornell University.