Colorectal cancer is the third-leading cause of cancer death in the United States. The American Cancer Society estimates that, in 2022, about 106,180 people will be diagnosed with colon cancer and 44,850 people will be diagnosed with rectal cancer. Vi K. Chiu, MD, PhD, director of the Gastrointestinal Oncology and Molecular Precision Programs at Cedars-Sinai The Angeles Clinic and Research Institute recommends six steps to lower your risk.
Get screened. When detected early, colorectal cancer is highly treatable. Screening can help physicians detect and remove polyps before they become cancer. Adults at average risk for colorectal cancer should begin testing at age 45. Adults with parents, grandparents, or siblings who have had colorectal cancer should begin screening at age 40, or 10 years before the diagnosis of the youngest first-degree relative.
Focus on diet. Studies have shown that diets rich in fruits, vegetables, and whole grains, such as oatmeal, brown rice, popcorn, and whole-wheat bread, are linked with a lower risk of colon or rectal cancer, Dr. Chiu notes. It is beneficial to eat only small amounts of beef, pork, and lamb, and eat fewer processed meats. It’s also helpful to keep an eye on your vitamin D levels. Analysis of a large, international study found that low levels of vitamin D were associated with a higher risk of getting colorectal cancer.
Exercise. Being active may reduce the risk of colorectal cancer by reducing inflammation in the body. People with inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis, are at much higher risk for colon cancer than the general population.
“Exercise may decrease gut inflammation and improve immune surveillance to prevent cancer,” Dr. Chiu explains.
Adults should aim for 150 minutes of moderate-intensity aerobic activity each week.
Manage weight. Being overweight or obese increases the risk of getting colon or rectal cancer because it can alter the function of hormones, such as insulin and leptin, Dr. Chiu says. Obese people have higher levels of insulin, which regulates blood sugar and can cause irregular cell growth in the colon.
Limit alcohol. Limit alcohol consumption to no more than one drink per day.
“Alcohol can cause intestinal damage. It is a toxin whose byproduct can damage DNA,” Dr. Chiu says. “The gut may develop inflammation, and the gut immunity is weakened. This can lead to colorectal cancer.”
Don’t smoke. Smoking increases the risk for colorectal cancer because it causes DNA damage and inflammation in the intestine and lungs, Dr. Chiu says. That can cause hypoxia, which, in addition to DNA mutations, may cause aberrant cells to develop in the body and transform into cancer.
A study of more than 4,900 participants, published in the British Journal of Cancer, found that current smoking was associated with a 59 percent higher risk of colorectal cancer, and former smoking was associated with a 19 percent increased risk. The risk was not increased among those who stopped smoking more than 20 years prior.