The 12 Best Ways to Prevent Colorectal Cancer

Beyond getting a colonoscopy starting at age 50, what can you do to prevent colorectal cancer? A lot, it turns out. The good news is that colorectal-cancer-preventing habits are nearly identical to those that help your heart.

"If you basically do what you're supposed to do to prevent coronary artery disease or to prevent a heart attack, then you're doing exactly what you should to prevent colon cancer," says Alfred Neugut, MD, professor of medicine and epidemiology at Columbia University Medical Center, in New York City.

Here are 12 tips for heading off colon cancer.

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, are thought to cut colorectal cancer risk. But routine use can cause serious problems, such as gastrointestinal bleeding.

People with high heart-attack risk can take a baby aspirin every day, but at the higher doses of aspirin that could help prevent colorectal cancer, the risks appear to outweigh the benefits.

Still, Dr. Neugut says, if you're taking aspirin to prevent coronary artery disease, you could get a bonus in colon-cancer prevention. Only a very high colon-cancer risk might warrant NSAIDs for cancer prevention, he says.

Most people know smoking causes lung cancer and heart attacks. But you can add colorectal cancer to the list.

Smokers are 18% more likely than nonsmokers to develop colorectal cancer, and 25% more likely to die from the disease, according to a 2008 study.

And a 2009analysis by the American Cancer Society found that people who had smoked for at least 40 years, or who didn't quit before they hit age 40, were 30% to 50% more likely to develop colon or rectal cancer than nonsmokers.

There's something about eating red meat—a lot of it—that seems to harm the intestines.

Numerous studies have linked red-meat consumption to a higher risk of colorectal cancer, as well as diets heavy in processed, salted, smoked, or cured meats such as bacon, sausage, and hot dogs.

If you just can't live without red meat, limit yourself to two 4-ounce portions each week, but choose lean cuts, trim the fat, and don't char it on a grill.

Heavy drinking may increase your risk of colorectal cancer.

A 2011 analysis found that people who have two or three drinks a day have a 21% higher risk of colorectal cancer than teetotalers or those who drink only occasionally.

People who drink more than 4 drinks per day have a 52% higher risk. It does not look like one type of alcohol is better or worse than another.

Part of the reason for the increased risk could be that heavy drinkers tend to have lower levels of folic acid, a vitamin that may protect against cancer.If you drink, it's best to stick to the recommended one drink a day for women and two drinks a day for men.

Adequate amounts of calcium and vitamin D may help prevent colorectal cancer—but don't overdo it.

It's a "reasonable approach" to stick with the recommended daily allowance of both nutrients (1,000 mg of calcium for women 19 to 50 years old and men 19 to 70; 1,200 mg daily of calcium for women at 50-plus and men 70 and over; 600 International Units of vitamin D for women and men until age 70, when they should start getting 800 IU of vitamin D), says Durado Brooks, MD, director of colorectal and prostate cancers at the American Cancer Society, in Atlanta.

Obesity is linked to colon-cancer risk, especially for men. And there's some evidence that abdominal obesity—aka belly fat—may be the key factor.

Men under 50 with excess fat around their middles are just as likely as thinner men older than 50 to have precancerous cells in their colons, according to a 2010 study.

Since big bellies increase the risk of a host of other diseases, from heart disease to diabetes, there's no downside to reducing your waistline.

This one doesn't have the rock-solid evidence of benefit that, say, quitting smoking does.

Although the research is in its early stages, some studies in mice and lab dishes, suggest you may be able to reduce your colorectal-cancer risk by eating black raspberries.

Eating a lot of fruits and vegetables in general could slightly lower your risk of colorectal cancer, while not eating enough could raise the risk. The American Cancer Society recommends "five or more servings of a variety of vegetables and fruits every day."

Want to really lower your risk? Get moving.

There's strong evidence that exercise cuts the risk of colon cancer and polyps, and sedentary living increases it.

One review of medical literature suggested that exercise reduces colon-cancer risk by 25%, although it does not appear to be associated with rectal cancer. So how active do you need to be? Get at least 30 minutes of moderate to vigorous activity at least five days a week, the American Cancer Society recommends, and get even more of a benefit if you make it 45 or 60 minutes.

"Screening for colorectal cancer is actually one of the very few cancer screening tests that can actually prevent the disease," says Dr. Brooks.

Testing usually starts at age 50, and options include

colonoscopy, sigmoidoscopy, and fecal occult blood testing.

"Compared to colonoscopy [fecal occult blood testing] is a very low-tech approach to testing, but it's also been shown that if done properly it can reduce the risk of developing and dying of colon cancer," Dr. Brooks says. "There are a variety of options. It's really an issue of patient preference and what patients have access to."

Heredity plays a big role in colon cancer; up to 20% of people who develop colorectal cancer have a relative with the disease. You should find out if your relatives had colorectal cancer or polyps, which are growths in the colon or rectum that can be precursors of the disease.

And it's important to find out how old they were when they were diagnosed.

If one of your first-degree relatives (a parent, sibling, or child) developed colorectal cancer or polyps before age 60 or more than one of your first-degree relatives did at any age, you should start getting screened for the disease at age 40, or 10 years before the age at which that relative was diagnosed, whichever comes first.

Up to 10% of colon cancers are caused by inherited genetic defects or mutations.

Hereditary nonpolyposis colon cancer and familial adenomatous polyposis are the most common colon-cancer-related genetic syndromes.

If you have one or more first-degree relatives with colorectal cancer or a related cancer, such as endometrial, and the disease appears in at least two successive generations in your family, talk to your doctor about whether you should have

colon-cancer genetic testing.

More screening and, in some cases, preventive surgery, may help.

There have been reports that green tea can prevent cancer, but the data is conflicting.

A study published in 2011 of Chinese men found a 54% lower incidence of colorectal cancer in those who regularly drank green tea.

Research also is being done to determine green tea's role in preventing many other types of cancer, including lung and pancreatic. Although the jury is still out on whether the beverage can help cut cancer risk, green tea is safe—so drink up!