Colon Cancer Risk May Be Increased by These Common Activities

Experts explain the everyday habits that may raise colon cancer risk and the prevention steps that can help lower it.

Reviewed by Dietitian Lisa Valente, M.S., RD

Key Points

• Many common behaviors can increase your risk for colon cancer.

• Being inactive, eating a low-fiber diet, drinking alcohol and smoking can raise risk.

• Screenings are important to catch any polyps that could become cancerous.

Colon cancer prevention might seem like something to think about later, especially if you feel fine. But colorectal cancer can develop without obvious symptoms, and some common everyday habits are associated with increased risk and are easy to overlook.

Colorectal cancer is expected to affect nearly 159,000 people in the U.S. in 2026, and rates are increasing in people younger than 65. “It’s important to remember that often colorectal cancer has no symptoms, which is why getting screened early and regularly as your doctor recommends is key,” says Pashtoon Kasi, M.D., M.S., medical director of GI medical oncology at City of Hope’s Orange County Lennar Foundation Cancer Center. Lifestyle changes cannot erase risk, but they can help lower it. We spoke with colorectal cancer experts to find out which common habits may increase colon cancer risk and which prevention steps may deserve your attention.

1. Sitting for Long Stretches

A low-movement day here and there will likely not impact your risk of developing colon cancer. The concern is a pattern of prolonged sitting and too little physical activity over time. Research has linked higher sedentary behavior with greater colorectal cancer risk, while regular physical activity is generally associated with lower risk.

“A sedentary lifestyle, characterized by prolonged sitting and low physical activity, significantly increases the risk of colon cancer through several biological mechanisms,” says Steven A. Lee-Kong, M.D., chief of colorectal surgery at Hackensack University Medical Center. He explains that inactivity can contribute to insulin resistance, chronic low-grade inflammation and excess body fat, all of which may create unfavorable conditions for colon health.

The American Cancer Society recommends adults get 150 to 300 minutes of moderate-intensity activity, or 75 to 150 minutes of vigorous activity, each week. Lee-Kong also recommends breaking up long sitting periods with standing, stretching or short walks. A 30-minute walk after work may be a place to start. If you sit for much of the day, short standing or walking breaks can be a good way to move a bit more.

2. Regularly Eating Too Little Fiber

A low-fiber eating pattern can leave waste sitting in the colon longer, giving potentially harmful compounds more time to interact with the cells lining the colon. It may also reduce production of short-chain fatty acids like butyrate, which are made when gut bacteria ferment fiber and help nourish colon cells and regulate inflammation. One systematic review and meta-analysis found that higher intakes of both soluble and insoluble fiber were associated with a lower risk of colorectal cancer.

Lance Uradomo, M.D., M.P.H., an interventional gastroenterologist, encourages patients to be more intentional about fiber intake. “Dietary fiber plays a significant role in digestive and gut health,” he says. “Fiber provides energy for our colon cells and helps keep the digestive tract flowing.”

An accessible way to start eating more fiber is to add it to meals you’re already eating. Try beans with lunch, berries at breakfast or a whole-grain side at dinner. Increasing fiber gradually gives your digestive system time to adjust, which can help reduce gas and bloating.

3. Drinking Alcohol Regularly

Regular glasses of wine, beer or hard liquor can increase colorectal cancer risk because of what happens after you drink them. As the body breaks down ethanol, it produces acetaldehyde, a carcinogenic compound that can damage DNA. Gut bacteria can also convert alcohol into acetaldehyde, which may expose cells in the colon lining more directly. In addition, alcohol may increase oxidative stress and interfere with folate, a B vitamin involved in DNA repair and cell division.

The U.S. Surgeon General’s advisory identifies colorectal cancer as one of at least seven cancers causally linked to alcohol use. While heavy drinking increases risk the most, even moderate and lighter drinkers have a higher risk.

“Reducing or eliminating alcohol is a lifestyle factor to focus on,” says Kasi. Because alcohol-related cancer risk appears to rise with regular exposure, any reduction can be a useful step. If alcohol is part of your routine, start with a change that feels realistic, such as adding a few alcohol-free nights each week, swapping a cocktail for a mocktail, or having fewer drinks in one sitting.

4. Smoking

Smoking exposes the body to carcinogens that can affect tissues beyond the lungs. In the colon, those chemicals may damage DNA and contribute to the growth of precancerous polyps, says Lee-Kong. One systematic review and meta-analysis found that smoking was associated with higher odds of colorectal cancer.

Kasi places tobacco use in the same prevention conversation as alcohol. “Tobacco smoking and heavy alcohol consumption are two of those risk factors,” he says. “Both can increase your cancer risk because of how they negatively impact healthy cells.”

For prevention, the goal is to reduce tobacco exposure as much as possible. If you have tried to quit before, it may help to talk with a clinician or pharmacist about medication, counseling or both. A quit line can also provide support between appointments.

5. Delaying Colorectal Cancer Screening

During a colonoscopy, clinicians can remove polyps before they have the chance to become cancerous. When screening is delayed, those precancerous changes or early cancers may have more time to grow unnoticed. Current American Cancer Society guidance recommends that adults at average risk start regular colorectal cancer screening at age 45 and continue through age 75 if they are in good health and have a life expectancy greater than 10 years.

There is also more than one way to get screened. Colonoscopy is one option, but stool-based tests and blood-based screenings are also available for some people. “Some sort of screening is better than no screening,” says Kasi.

The right test will depend on your risk level, including whether you have a family history of colorectal cancer, a personal history of polyps, inflammatory bowel disease, certain genetic syndromes or symptoms.

Symptoms should be evaluated at any age, even if you are younger than the usual screening starting point. Blood in or on your stool, a persistent change in bowel habits, ongoing abdominal pain or unexplained weight loss are reasons to talk with a doctor, notes Kasi.

Other Tips for Reducing Colon Cancer Risk

Beyond the health behaviors above, a few practical steps can help you catch changes earlier and make prevention feel more manageable.

• Know your family history. Tell your doctor if a parent, sibling or child has had colorectal cancer or advanced polyps. This can change when screening should begin.

• Be mindful of symptoms. Rectal bleeding, ongoing bowel changes, abdominal pain or unexplained weight loss should be evaluated, even if you are younger than the standard screening age.

• Limit red and processed meats. The American Cancer Society recommends a cancer-prevention eating pattern that limits red and processed meats. Try swapping in beans, lentils, poultry or fish more often, especially if processed meats are part of your usual breakfast or lunch routine.

Our Expert Take

The most important step is to stay on schedule with colorectal cancer screening. Colon cancer can develop before symptoms appear, and screening can find early cancer or, during colonoscopy, remove certain polyps before they become cancer. For adults at average risk, that usually means starting at age 45.

Apart from screenings, moving more, eating enough fiber, drinking less alcohol and avoiding tobacco may all help reduce risk. These changes work best when they become part of your normal routine, so choose the one you can repeat most consistently and build from there. If you notice rectal bleeding, a lasting change in bowel habits, ongoing abdominal pain or unexplained weight loss, call your doctor rather than waiting for your next routine screening.

Read the original article on EatingWell