Diseases and conditions that affect the colon, or large intestine, are common and can range in severity from uncomfortable to life-threatening. The relationship between nutrition and intestinal health is inherent as the primary purpose of the intestines is to digest and absorb nutrients from food.
Significance
Poor nutrition can lead to intestinal illnesses and vice versa. Constipation, irritable bowel syndrome, diverticulitis, inflammatory bowel disease and colorectal cancer are all conditions that involve the colon and have important nutritional considerations. Constipation is defined as having infrequent, small, or painful stools that are difficult to eliminate. It is a common condition affecting over 4 million Americans, especially older adults and pregnant women. Irritable bowel syndrome (IBS) is a disorder characterized by abdominal cramping, bloating, constipation and diarrhea. When bulges or pouches form along the lining of the intestines, the condition is called diverticulosis. These pouches can become acutely inflamed, a condition called diverticulitis. Diverticulitis can cause pain, bloating, cramping and constipation. Inflammatory bowel disease (IBD) includes Crohn's disease and ulcerative colitis, which are diseases that cause inflammation and ulcers in the large intestine. Complications can include diarrhea, weight loss, nutritional deficiencies and dehydration. Colon cancer is perhaps the most dangerous of diseases affecting the colon, accounting for nearly 50,000 deaths in 2009. Attention to diet can help prevent constipation, diverticulitis and colorectal cancer, and can help avoid complications in IBS and Crohn's disease.
Components
A diet that is designed to prevent colon health problems is high in fiber and fluids and low in fat. A diet low in fiber can lead to constipation, as most Americans eat less than half of the recommend 20-35 g per day, according to the National Center for Health Statistics. Increasing fluids and decreasing intake of fats, especially from animal sources, can also help prevent constipation. Lack of fiber and exercise is also associated with higher risk of diverticular disease, according to a research review done at UNESP School of Medicine in Sao Paulo, Brazil. Numerous dietary factors have been studied for their potential preventative effect on colon cancer, including higher intakes of fruits and vegetables, whole grains, lower intake of meats, and alcohol in moderation only.
Dietary Sources
Fiber intake can be increased by consuming more fruits and vegetables and beans, substituting whole grains for white breads, white pasta or white rice, and consuming a breakfast cereal that contains bran. Both soluble and insoluble fibers are useful in the prevention of constipation, diverticular disease and colorectal cancer. Soluble fiber is found in oats, beans, and fruits and vegetables without tough skins. Insoluble fiber is found in whole wheat products, corn and wheat bran, nuts, seeds, and fruit and vegetable skins. Plant foods contain benefits beyond that provided by fiber. Fruits and vegetables contain many antioxidants, including vitamins C and E and selenium. Whole grains are also a source of selenium, a mineral with antioxidant properties. Folic acid, found in fortified cereals and breads, lentils, asparagus, and orange juice is also beneficial, as is calcium found in low-fat dairy, fortified soy milk or orange juice, and leafy green vegetables. According to a 2007 study in the "Journal of Nutrition," garlic also exerts a protective effect against colon cancer in animal studies. Limiting total intake of fat, especially saturated fat found in cheese, full-fat dairy and meats, is also important for colon health. Alcohol should also be limited to only one drink per day for women and two drinks per day for men. Water and fruit juices are better choices for beverages, as they can help prevent constipation.
Modifications
In the case of diseases such as IBS and IBD, different dietary modifications may be necessary. Many people with IBS find their symptoms are relieved or worsened by certain food, but it is difficult to establish which foods are causing the reaction. Eliminating all suspected foods from the diet until symptoms resolve, then gradually re-introducing the foods back into the diet may help determine which foods trigger symptoms. Researchers from the University of North Carolina performed a review of current research about diet and IBS, and concluded that daily use of peppermint oil can be beneficial. Limiting fructans (found in wheat and onions) and sugar alcohols such as sorbitol (found in some artificially sweetened products) appears to be helpful. The use of prebiotics and probiotics, found in fermented dairy products such as yogurt and buttermilk and some fortified foods, may be beneficial, but more research is needed. Insoluble fiber may worsen symptoms, but soluble fiber may alleviate constipation in people with IBS. Patients experiencing an acute flare-up of IBD may need to avoid bulky grains and seeds, spicy foods, alcohol or milk products. Diarrhea can cause dehydration, so extra fluids and electrolytes are needed to restore fluid balance. If a person suffering from IBD is having difficulty maintaining or gaining weight, protein shakes and nutritional supplements may be prescribed by the physician. Poor absorption of nutrients such as iron can lead to vitamin or mineral deficiencies, which can be corrected with prescribed supplements.
Additional Benefits
Following a diet high in fruits, vegetables, whole grains and water, and low in animal fats and alcohol can help prevent chronic health problems related to the intestines. This dietary pattern also promotes overall well-being by helping with weight control, increasing energy levels, and helping to regulate blood sugar and blood cholesterol levels.
References
- National Digestive Diseases Information Clearinghouse: Constipation
- Journal of the American Dietetic Association: The Role of Diet in Symptoms of Irritable Bowel Syndrome in Adults: A Narrative Review
- Jackson Siegelbaum Gastroenterology: Prevention of Colon Polyps and Cancer
- Journal of Nutrition: Does Garlic Reduce Risk of Colorectal Cancer? A Systematic Review
