The Size of a Pea and a Lot More Dangerous

Colorectal polyps are small, noncancerous (benign) clumps of cells that grow in the rectum and colon. Over the course of 10–15 years, some of these polyps -- usually the ones that are larger than a pea -- can become cancerous. Fortunately, regular screening for colorectal cancer helps to identify and remove polyps, often before they progress to cancer.

It is not known why polyps develop, but some people are more prone than others. For instance, the older you get -- especially after age 50 -- the more likely you are to have polyps. You're also more likely to develop polyps if you've had them before (polyps tend to recur) or if someone in your family has had polyps or cancer of the colon.

Your behavior also influences your risk: Eating a lot of fatty foods, smoking cigarettes, drinking alcohol, not exercising, and being over weight can all contribute to the formation of polyps.

Q. I've had a colon polyp removed. What can I do to prevent colorectal cancer?

A. One crucial step is to have a follow-up colonoscopy every three to five years, depending on the number and size of your polyps.

You also need to get moving. The American Cancer Society stresses the importance of exercise for those trying to prevent polyp recurrence. Excess body weight and inactivity are linked with shorter survival times; one study found that people who exercised regularly were about half as likely to die of colorectal cancer within four years as those who did not exercise.

No diet is guaranteed to prevent colorectal cancer recurrence, but experts suggest this recipe to help lower your risk:

• Get most of your foods from plant sources (fresh vegetables, fruits, and nuts).
• Avoid processed foods and limit those high in saturated fats (especially beef).
• Choose chicken, fish, or beans as your main protein sources.
• Avoid junk foods, including sodas and sugar-laden snacks.
• Have no more than one alcoholic drink per day.
• Get most of your nutrients from foods rather than supplements.

Finally, although some research has suggested that NSAIDs may prevent colorectal cancer, the U.S. Preventive Services Task Force recently concluded that the risks of long-term NSAID use -- such as gastrointestinal bleeding, kidney problems, and hemorrhagic (bleeding) stroke -- exceed the potential benefits for people at average risk for colorectal cancer.