A bowl full of bright green steamed broccoli. You say either "Yum!" -- or "Where's the double cheeseburger?" But you know the broccoli is good for you, especially sans melted cheese. The question is, how good? And more to the point, can it -- or any food -- help prevent disease, such as cancer?
The answer is yes -- some foods do show cancer-fighting properties, though no one is yet able to say one food or another can stop cancer in its tracks. Still, a body of research suggests an overall healthy diet filled with colorful fruits and vegetables is the key to skirting heart disease, diabetes, and possibly cancer, too.
Note: Separate PDQ summaries on Oral Cancer Prevention and Lip and Oral Cavity Cancer Treatment are also available.
There is inadequate evidence to establish whether screening would result in a decrease in mortality from oral cancer.
Magnitude of Effect: No evidence of benefit or harm.
Study Design: Evidence obtained from one randomized controlled trial.
Internal Validity: Poor.
Consistency: Not applicable (N/A).
In fact, scientists know more about what not to eat -- processed meats, salty foods, sugary drinks, huge helpings of red meat -- than which fruits and vegetables to pile on your plate. But they do know those foods matter.
A comprehensive review of thousands of studies on diet, physical activity, and weight conducted for the World Cancer Research Fund and the American Institute for Cancer Research pointed to the benefits of eating mostly foods of plant origin. Foods such as broccoli, berries, and garlic showed some of the strongest links to cancer prevention.
They're low in calories and fat and power-packed with phytochemicals and antioxidants that may help reduce your cancer risk.
Antioxidants, Phytochemicals, and Cancer
You've heard of antioxidants, such as vitamin C, lycopene, and beta-carotene, which are in many fruits and vegetables. Studies suggest that people who eat meals that are rich in fruits and vegetables have a lower risk of cancer. A variety of chemicals from plants known as phytochemicals also seem to protect cells from harmful compounds in food and in the environment, as well as prevent cell damage and mutations, says Jed W. Fahey, ScD, MS, a faculty research associate at Johns Hopkins University School of Medicine, who studies how cruciferous vegetables help protect against disease.
A diet that could ward off cancer really doesn't look that different from the healthy foods you should be eating anyway, says Wendy Demark-Wahnefried, PhD, RD, a professor of behavioral sciences at the University of Texas M.D. Anderson Cancer Center in Houston. That means plenty of fruits and vegetables, as well as whole grains and lean meat or fish.