Colon Cancer Risk Factors: 13 Things That Might Increase Your Risk

1. Age

Age is one of the strongest risk factors for colon cancer. Rates begin to rise between ages 40 and 50, and your risk continues to increase as you get older.

That’s why routine screening is recommended starting at age 45 for people at average risk. While colon cancer can occur in younger adults, it’s still much more common after midlife.

2. Race

In the U.S., colon cancer occurs more often in Black Americans than in white Americans. Black adults are also more likely to be diagnosed at later stages and to die from the disease. These differences aren’t due to race itself. Rather, they’re likely due to social factors. A combination of lack of access to healthcare, colon cancer screening, and nutritious foods are all factors that account for the higher risk.

Because of this increased risk, some medical organizations used to recommend earlier screening in Black adults. But current national guidelines now recommend starting at age 45 for everyone at average risk.

3. Obesity

Obesity is also a risk factor for colon cancer. It isn’t clear how obesity increases the risk for colon cancer. But some researchers have noted a higher level of inflammation and hormone changes in those with excess body weight, which could play a role. 

People with obesity may also be more likely to have other health conditions that can increase the risk — such as diabetes (see below). 

4. Type 2 diabetes

People with Type 2 diabetes have a higher risk of developing colon cancer. Researchers believe this may be related to higher insulin levels and chronic inflammation, both of which can promote cancer growth.

Several large studies have found that Type 2 diabetes is linked with a higher risk of both colon and rectal cancer. Keeping blood sugar under good control, maintaining a healthy weight, and staying physically active may help lower overall cancer risk.

5. Gender

Men have a slightly higher risk of developing colon cancer than women. They’re also more likely to develop precancerous colon polyps. The reasons for this difference aren’t fully understood. Hormonal differences, lifestyle factors, and screening patterns may all play a role. 

That said, colon cancer still remains common in women. That’s why screening is recommended for everyone starting at age 45, regardless of gender.

6. Inflammatory bowel disease (IBD)

Chronic inflammation of the colon increases your risk of colon cancer. This is why people with inflammatory bowel diseases (IBD) like Crohn’s disease and ulcerative colitis have a higher risk, especially if they’ve had the disease for many years.

The longer your colon is inflamed, the greater your risk. Because of this, people with IBD often start colon cancer screening earlier and may need colonoscopies more frequently than average-risk adults.

7. Hereditary syndromes

Some inherited genetic conditions can increase colon cancer risk too. The most common are Lynch syndrome and familial adenomatous polyposis (FAP).

Lynch syndrome increases your risk of colon cancer at a younger age and can also raise your risk of other cancers. FAP causes hundreds to thousands of polyps to form in your colon, often beginning in adolescence. Without treatment, colon cancer is very likely to develop.

Genetic counseling and earlier, more frequent screening are recommended for people with these syndromes.

8. Family or personal history

If you’ve had colon cancer before, you’re at higher risk of developing it again. You’re also at increased risk if you have a first-degree relative (meaning a parent, sibling, or child) with colon cancer, especially if they were diagnosed before age 60.

Family history can reflect shared genes, shared environmental factors, or both. If you have a strong family history, screening is usually recommended earlier than age 45.

9. Low vitamin D levels

Low vitamin D levels have been linked to a higher risk of colon cancer in observational studies. Vitamin D may help reduce inflammation and keep your immune system strong, which could play a role in cancer prevention.

While research shows a link, it’s not yet clear whether taking vitamin D supplements directly lowers colon cancer risk. 

10. Alcohol

Drinking alcohol increases your risk of colon cancer. Even moderate alcohol use has been linked to a higher risk, and the risk rises as alcohol intake increases.

Alcohol may damage cells in the lining of the colon that lead to changes in your DNA over time. Limiting how much alcohol you drink — or avoiding it altogether — can help lower your risk.

11. Tobacco

Smoking cigarettes increases the risk of colon cancer. And the longer someone smokes, the greater their risk.

Tobacco smoke contains chemicals that can damage your DNA and promote cancer growth throughout your body, including in your colon. Quitting smoking can reduce your risk, and it provides many other health benefits as well.

12. Diet

What you eat plays an important role in colon cancer risk. Diets high in red and processed meats — like bacon, sausage, and deli meats — are linked to a higher risk of colorectal cancer. Researchers believe certain compounds formed during processing or high-temperature cooking may damage the lining of the colon.

On the other hand, diets rich in fruits, vegetables, and fiber are linked with a lower risk. Fiber may help by moving waste through the colon more quickly and supporting a healthy gut environment.

13. Sedentary behavior

Spending long periods sitting — like during desk work or extended screen time — may increase your colon cancer risk, even in people who exercise regularly.

Prolonged sedentary time is linked to metabolic changes that can promote inflammation and insulin resistance. Breaking up long periods of sitting with movement throughout the day may help reduce your overall risk.

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