Eight Good Bets for Preventing Colon Cancer
For: Wellness Made
Easy, July 2003
Darryl Strawberry, the New York Yankees outfielder, recently underwent surgery for colon cancer, which had the beneficial side effect of bringing this subject before the public. Some cancers are always in the public eye, but seldom colon cancer—which is ironic, because this is one cancer where preventive action may truly save your life. Nobody knows exactly what causes colon cancer. But the latest news about prevention is encouraging. Here are some good bets, plus a few educated guesses and theories.
1 What you eat: Colorectal cancer is most common in countries where the diet is typically "western": high in fat, calories, meats (especially red and processed meats), sugar, and refined grains, and low in fruits, vegetables, and whole grains. A healthy diet, on the other hand, is high in vegetables, fruits, and whole grains, and low in animal fats. This is the old, familiar "heart-healthy" diet. It can include small amounts of low-fat meats as well as fish and low-fat or fat-free dairy products.
Why is the "western" diet risky for the colon?
• Eating large amounts of fat may be unhealthy for the colon. Some fat passes into the colon undigested, and the bacteria there act upon the fat, producing potentially carcinogenic substances that may damage the colon lining.• High-calorie diets often lead to weight gain, particularly in sedentary people. Obesity increases the risk of colon cancer.
• This kind of diet promotes constipation, and chronic constipation may in turn promote colon cancer.
• A high-fat, high-calorie diet lacks fiber and important nutrients (see below).
Why is the heart-healthy diet good for your colon?
• It is naturally high in fiber, which may protect against colon cancer, though studies have yielded conflicting results.• High intakes of beta carotene, calcium, and the B vitamin folic acid, all of which are abundant in a healthy diet, seem to protect against colon cancer. Vitamin C is protective, too. Vitamin D may also play a role.
• A recent study found that women with high intakes of folic acid (above 400 micrograms a day) from multivitamins for at least 15 years were 75% less likely to develop colon cancer.
• Cruciferous vegetables (such as broccoli, cabbage, and cauliflower) contain other substances besides vitamins and fiber that may also reduce your risk.
2 What you drink: The role of alcohol in colon cancer is still uncertain. Some studies have found a link between beer and ale consumption and rectal cancer, and some researchers think that drinking seven drinks or more a week may promote the growth of precancerous polyps (benign growths of tissue inside the bowel).
3 Whether you smoke: Smoking has been linked to colon cancer in some studies, and it appears to promote precancerous polyps.
4 How you cook: Charbroiled and fried foods are suspected of promoting colon cancer, because certain cancer-causing compounds called heterocyclic amines are produced when meats—especially fatty meats—are cooked at very high temperatures. Our advice has always been to go easy on such foods, if you eat them at all. Pick low-fat meats, or trim the fat before cooking. Protect meats from rising smoke, and never allow fat to drip on a high flame. Protect meats from the fire with aluminum foil or drip pans. Don't eat charred foods.
5 Whether you take aspirin: There's some evidence that long-term use of aspirin and other nonsteroidal anti-inflammatory drugs such as ibuprofen (but not acetaminophen) may help prevent colon cancer. There's still much to be learned about how much aspirin you need and how long you need to take it. Doctors are not yet advising people at low risk for colon cancer to start taking aspirin for its anticancer effects. But if you are already taking aspirin in low doses for its cardiovascular benefits, or regular doses for pain relief, you are probably reaping the additional benefits. The theory is that aspirin stops the production of enzymes needed for tumor growth. Its anti-inflammatory properties may help, too.
6 How active you are: People who exercise regularly, even a moderate amount, have a lower risk of colon cancer. Exercise helps prevent constipation; it also helps control body weight and prevent obesity. And people who exercise regularly tend to eat healthier diets.
7 Your genes: Your genetic makeup and family history also matter. If you know that colon cancer or precancerous polyps run in your family—particularly if your parent, grandparent, sibling, or other close relative has had colon or rectal cancer—and/or if you have ulcerative colitis or any chronic inflammatory bowel disorder, you are in a higher-risk group. Genetic testing for colon cancer often produces confusing results or supplies no useful information. You should discuss your risk factors with a physician or qualified genetics counselor.
8 Screening tests you undergo: Early screening can save your life, particularly if you are in a high-risk group. It's possible now to detect precancerous polyps and remove them before they become malignant.
UC Berkeley Wellness Letter, December 1998