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. It's the third most common cancer and the third deadliest cancer in the U.S. 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; 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 who specializes in colorectal cancer at Rush University Medical Center.

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 (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 percent of colorectal cancer can be prevented through lifestyle changes like healthy eating, according to the Colon Cancer Foundation.

"Fewer than 10 percent of colon cancers are hereditary, which means a lot of it is lifestyle," says Heather Rasmussen, PhD, a registered dietitian at Rush. "Therefore, good nutrition is an important aspect of good colon health."

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 some of these diet recommendations:

• Limit red meat consumption and steer clear of processed meats. According to the ACS, the risk of colon cancer increases by 15 to 20 percent 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 hotdogs, per day. "You can still have a little bit of red meat — about two four-ounce servings of red meat per week," says Rasmussen. "However, it is best to limit processed meats to a special treat now and then because they have other components, such as preservatives, that may cause cancer."
• 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.
• Up your fiber intake. Eating a high-fiber diet is good for overall intestinal and colon health. "On average, Americans eat about 13 grams of fiber a day, but we're supposed to have 25 to 35 grams," says Rasmussen. The best way to add fiber into your diet is through fiber-rich fruits and vegetables, such as raspberries, pears, apples, bananas, oranges, cooked artichoke, peas, broccoli and corn. Whole grains and legumes are also good sources of fiber. Fiber aids colon health by helping to keep you regular and prevent constipation. This may then lower your risk of developing hemorrhoids and small pouches in your colon that can lead to diverticular disease.
• Drink your milk. Recent studies have found that calcium and vitamin D may be associated with a decreased risk of colorectal cancer. However, the ACS does not recommend increasing your calcium intake above the recommended amounts because there is a potential increased risk of prostate cancer associated with high calcium intake, exceeding 2,000 milligrams a day. Instead, make sure you’re getting the recommended amount of calcium in your diet: depending on age, that is 1,000 milligrams to 1,300 milligrams a day (three to four eight-ounce glasses of low-fat or fat-free milk). Other dietary sources of calcium include leafy greens, such as spinach, kale and collard greens.
• Choose grains wisely. Whole grains are foods that contain all their essential parts and naturally occurring nutrients. 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.