Eating for a healthy colon
Just as diet can have a positive or negative impact on heart, brain and bone health, your colon's overall health can be affected by what you eat.
The colon is a crucial part of the digestive system, and many different conditions can cause it to work improperly. Some of these include inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease; diverticular disease; irritable bowel syndrome; and colorectal cancer.
Treatment for these conditions includes diet and lifestyle modifications, medications and/or surgery.
Colorectal cancer is one of the most serious colon diseases. Risk factors for colon cancer include age (risk increases over age 50); race (Blacks have the highest rates of colorectal cancer in the U.S.); family history; previous polyps; inflammatory bowel disease; smoking; physical inactivity; and heavy alcohol use.
"There is also a strong correlation between obesity and having a higher risk of getting cancer in the colon," says Joshua Melson, MD, MPH, a gastroenterologist at Rush University Medical Center.
Physical inactivity is also a proven risk factor. "Colon cancer is one of seven cancers directly related to physical activity participation," says Hannah Manella, MS, RD, a registered dietitian and certified clinical exercise physiologist at the Rush University Cancer Center. "Physical activity recommendations to decrease your risk for colon cancer is 150 minutes of moderate-intensity activity per week. Any activity is better than nothing. Start small, even five-minute sessions add up."
A weighty connection
According to the National Cancer Institute, the association between obesity and increased colon cancer risk may be due to multiple factors, including increased levels of insulin in the blood, a condition that may occur more often in obese individuals. Increases in insulin and associated conditions such as insulin resistance may promote the development of certain tumors, including those in the colon.
The American Cancer Society, or ACS, reports that the links between diet, weight, exercise and colorectal cancer risk are some of the strongest for any type of cancer. In fact, an estimated 50% to 75% of colorectal cancer can be prevented through lifestyle changes like healthy eating, according to the Colon Cancer Foundation. Therefore, good nutrition is an important aspect of good colon health.
But, it's not all about the number on the scale. "Healthy food choices and physical activity can provide a benefit even if you don't actually lose weight," says Manella. "I try to emphasize making consistently good choices."
Diet dos and don'ts
Diets high in vegetables, fruits and whole grains and low in red and processed meats have been associated with a decreased risk of colon cancer, according to the ACS. To help promote good colon health, follow these five diet recommendations:
1. Add plant-based foods into your diet
"First and foremost, eat a diet rich in whole grains, vegetables, fruits, nuts, seeds, beans and lentils—basically, a plant-based diet," says Manella. "Of course, plant-based does not mean eating only plants. But at least half of your plate should comprise plant foods, which provide many beneficial vitamins, minerals and antioxidants, and are packed with fiber—our natural cancer-fighting compounds."
2. Limit red meat consumption
According to the ACS, the risk of colon cancer increases by 15% to 20% if you consume 100 grams of red meat (the equivalent of a small hamburger) or 50 grams (equivalent of one hot dog) of processed meats, like sausage, bacon or hot dogs, per day.
"We recommend prioritizing chicken, turkey and fish over beef, pork and lamb," says Manella. "However, if you choose to eat red meant, we recommend no more than 18 ounces of red meat per week (about three small servings the size of a deck of cards)."
The way you cook your red meat can also add to your risk. "We recommend limiting cooking red meats at very high temperatures that cause charring," she says. "This causes the meat to form chemicals called heterocyclic amines and polycyclic aromatic hydrocarbons, which are linked to increased cancer risk."
3. Hold the sugar
Studies have found that people with ulcerative colitis and Crohn's disease often have diets high in sugar and low in fiber.
While sugar has not been directly associated with the progression of colon cancer, foods high in sugar are often high in calories and can lead to weight gain and obesity.
"Naturally occurring sugars in fruit and dairy are OK and provide a number of beneficial vitamins and minerals," says Manella. "But we recommend limiting added sugar to less than 35 grams a day."
She also recommends taking a closer look at beverages. "Look for sugar-free alternatives like sparkling water, unsweetened teas or coffees, or fun natural flavor combinations like blueberry and cucumber or lemon and ginger."
4. Up your fiber intake
Eating a high-fiber diet is good for overall intestinal and colon health.
"The American Institute for Cancer Research and ACS recommends aiming for at least 30 grams of fiber from food sources each day," says Manella. "Fiber naturally occurs in plant-based foods. Focus on incorporating a variety of whole grains, colorful fruits and vegetables, nuts, seeds and beans into your diet. If you can't meet your needs with fiber foods alone, a fiber supplement like Metamucil can be a helpful tool to reach your fiber goal."
Fiber aids colon health by helping to keep you regular and prevent constipation by moving foods through your gastrointestinal tract. This may then lower your risk of developing hemorrhoids and small pouches in your colon that can lead to diverticular disease.
5. Choose grains wisely
Whole grains are grain products that have not been stripped of their nutrient and fiber-packed exterior. The Dietary Guidelines for Americans recommend that all adults eat at least half of their daily grains as whole grains, about three to five servings.
Some readily available whole grains include barley, quinoa, whole wheat flour, wild and brown rice and oatmeal. These foods contain more colon-friendly vitamins, minerals, fiber, essential fatty acids, antioxidants and phytochemicals (natural compounds in plants that have a beneficial effect on the body) than their refined grain counterparts, such as white flour and white rice.
Manella notes that an easy way to determine if the food is a whole grain is to check the label. "If the first ingredient on a grain product says 'enriched," it is not a whole grain," she says.
Make screening a priority
While eating right can help keep your colon happy, the most powerful way to prevent colon cancer is through screening. A colonoscopy is a structural examination of the colon that allows physicians to both screen for and prevent colorectal cancer.
"Colonoscopy reduces the risk of developing colon cancer because we can find precancerous polyps during the test and remove them," says Melson. "This test is unique to most screening tests because we can actually look for precancerous growths and remove them during the procedure, which ultimately reduces a person's risk of developing colon cancer."
If detected early, up to 95% of colorectal cancers are curable, according to the Colon Cancer Foundation. "Colon cancer is a largely treatable condition," says Melson. "For colorectal cancer, we have a test, it is not complicated and it is extremely effective in preventing it and catching it early."