Understanding Colorectal Cancer

Risk Factors for Colorectal Cancer

This is the third article in the Understanding Colorectal Cancer Guide. This guide was developed by the HealthTree Education Team and was last updated and reviewed on April 3rd, 2026. 

Anything that increases your chance of developing cancer is called a risk factor. Sometimes, risk factors directly cause cancer. For example, smoking causes damage to lung cells that lead to lung cancer. Most often, though, risk factors do not directly cause cancer. Instead, many small changes over time lead to the genetic changes that cause cancer.

It is important to remember that having one or more risk factors for colorectal cancer does not guarantee you will develop that colorectal cancer. It is also possible to develop colorectal cancer even if you do not have any known risk factors.

Researchers are still learning how colorectal cancer develops.

What raises your risk for developing colorectal cancer?

• Age. The risk of colorectal cancer increases with age. Most cases are diagnosed in people over 50, but rates are rising among younger adults.
• Personal history of inflammatory bowel disease. People with Crohn's disease or ulcerative colitis have a higher risk of colorectal cancer.
• Family history. Having a first-degree relative (parent, sibling, or child) who had colorectal cancer or adenomatous polyps raises your risk, especially if they were diagnosed before age 60.
• Hereditary syndromes. Certain inherited gene mutations significantly increase colorectal cancer risk:
  • Lynch syndrome (hereditary non-polyposis colorectal cancer, or HNPCC): the most common hereditary colorectal cancer syndrome
  • Familial adenomatous polyposis (FAP): causes hundreds or thousands of polyps to grow in the colon
  • Attenuated FAP, MUTYH-associated polyposis, and other hereditary polyposis syndromes
• Race and ethnicity. Black Americans have higher rates of colorectal cancer and are more likely to be diagnosed at an advanced stage. Jewish people of Eastern European descent (Ashkenazi Jews) also have a higher risk due to certain inherited gene mutations.
• Type 2 diabetes. People with type 2 diabetes have a moderately higher risk of developing colorectal cancer. Researchers believe this is partly due to insulin resistance¹ The body compensates by producing extra insulin, and those elevated insulin levels may stimulate the growth of cells in the colon. Chronic inflammation associated with diabetes may also play a role.
• Diet. A diet high in red and processed meats has been linked to a higher risk of colorectal cancer. A diet high in fruits, vegetables, and whole grains may lower risk².
• Physical activity. Being physically inactive increases the risk of colorectal cancer.
• Overweight and obesity. Excess body weight is associated with a higher risk of colorectal cancer.
  Smoking. Long-term smoking increases the risk of colorectal cancer.
• Heavy alcohol use. Drinking alcohol in large amounts has been linked to colorectal cancer.

SOURCES:

1. Diabetes and Colorectal Cancer Risk: Clinical and Therapeutic Implications
2. The Role of Diet and Lifestyle in Colorectal Cancer Incidence and Survival