The Anticancer Diet

Eat to tip the odds in your favor

By Elaine Magee, MPH, RD
WebMD Weight Loss Clinic - Expert Column

Don't you wish there were a diet that could assure you a life free from cancer? Most experts agree it doesn't exist -- yet. But there is a way to eat and live that could put the odds of preventing cancer in your favor.

The dietary habits that tend to increase our cancer risk come down to too much and too little: Too much red meat, alcohol, fried foods, refined carbohydrates and sugars, and too much body fat; too few phytochemical-rich plant foods and too little exercise. (Of course, you already know you shouldn't smoke or get too much sun.)

To decrease our risk, for example, we want to eat whole grains (such as whole wheat, barley, and oats) and plenty of fruits and vegetables. Many fruits and vegetables have cancer-fighting potential. For example, lycopene, a phytochemical found in cooked tomatoes and tomato products, has been shown to slow the growth of breast, lung, and endometrial tumors and to reduce prostate, stomach, and pancreatic cancer risks.

Randall Oyer, MD, chairman of medical oncology at John Muir Medical Center in Walnut Creek, Calif., isn't afraid to say that nutrition plays a role in cancer prevention, but he cautions against making a connection within a short time frame. "What a person has been eating a year before they were diagnosed with breast cancer, for example, probably isn't as relevant as what they've been eating a decade or two before," he explains.

And most cancer researchers admit there's stronger scientific evidence for a link between diet and colon cancer, for example, than for one between diet and breast cancer -- the cancer that so many women fear the most. But we're learning more every day.

In the past year, scores of studies have been published on diet and breast cancer alone. And more and more of this research is distinguishing between the effects that certain nutrients have on women before menopause and after.

In my opinion, future studies also should look at the differences between types of fat and types of carbohydrates. Some studies have suggested that higher-fiber, high-phytochemical plant foods (which are rich in carbohydrates) may have protective effects, while refined carbohydrates and sugars may have negative ones. Others have suggested that olive oil (and monounsaturated fat) and omega-3 fatty acids may help reduce breast cancer risks.

Should It Really Be "10-a-Day"?

Although some earlier scientific studies failed to find a link between eating vegetables and fruits and reduced risk for some types of cancers, more recent ones are reversing that trend.

For example, a recent study in Northern Italy suggested that raw vegetables may help protect against both breast and prostate cancer. Other research has indicated that cruciferous vegetables (like broccoli, cauliflower, and cabbage) may play a role in reducing breast-cancer risks in premenopausal women. One of the benefits of cruciferous veggies may be their abundant supply of isothiocyanates. These phytochemicals may help increase certain enzymes that detoxify cancer-promoting chemicals.

While we're on the subject of broccoli, another phytochemical in this vegetable recently made medical news. A report from the University of Illinois at Urbana-Champaign was the first to show how the isothyiocyanate found in broccoli, brussels sprouts, and kale -- called sulphoraphane -- can block late stages of the cancer process. Using human breast cancer cells in the lab, researchers were able to hinder the growth of the cancer -- much like certain drugs do.

Various fruits and vegetables have also been scientifically linked with prevention of colon, mouth, esophageal, lung, and stomach cancers. Population studies have repeatedly suggested that certain types of produce -- dark green vegetables; tomatoes; citrus; cruciferous vegetables such as broccoli and cabbage; and carotene-rich ones such as carrots and cantaloupe -- reduce overall cancer risk.

More and more studies are being done all the time. But obviously, fruits and vegetables are very important to our health in general. It's hard to argue with those food choices!

Bottom line: Strive to eat 10 servings (about 1/2 cup is a serving) of fruits and vegetables a day, choosing carotene-rich produce, dark green vegetables, cruciferous vegetables, tomatoes, and citrus when possible.

Specific Nutrients or Foods with an Anti-Cancer Connection