Diet is a major factor in 5 of the 10 leading causes of death: heart disease, cancer, stroke, diabetes mellitus, and atherosclerosis. These diseases account for 70% of all deaths in the United States. Over half the calories consumed in this country are from refined foods, from which the bran, germ, and oil have been removed. The average intake of fiber is only 11gm per day, compared to the daily recommended intake of 20 to 30gm. Fiber is important in the prevention of constipation, diverticulosis, colon polyps, varicose veins, hemorrhoids, appendicitis, hiatal hernia, peptic ulcer disease and probably colon cancer.
Soluble fiber consists of the plant’s sticky components, including pectins, gum, and mucilage. Soluble fiber comes from the plant’s skeleton, which consists of lignin, cellulose, and hemicellulose. Foods containing water soluble fiber include fruit, vegetables, oats, barley, wheat, whole grains, cereals, legumes, and psyllium. Most plant foods provide insoluble fiber also. Water insoluble fiber assists in maintaining regular bowel movements, but may have an adverse or detrimental effect on irritable bowel syndrome and Crohn’s disease. Soluble fiber may be beneficial in atherosclerosis, IBS, hypercholesterolemia, hypertriglyceridemia, diabetes, obesity, hypertension, dumping syndrome, and gallstones.
Soluble fiber is fermented by colonic microflora resulting in the production of short chain fatty acids (SCFAs), such as butyric acid. In addition to promoting beneficial SCFA production and intestinal motility, dietary fiber can help to bind endotoxins and facilitate their elimination via the bowel.
Different types of fiber may have protective benefit in various bowel disorders such as irritable bowel syndrome, diverticulosis, colorectal cancer and other conditions such as diabetes, hypercholesterolemia and obesity. The fiber of choice for irritable bowel syndrome is methylcellulose or polycarbophil; for diverticulosis is psyllium, methylcellulose or polycarbophil; for colorectal cancer is psyllium, pectin or guar gum; for diabetes any supplement; for hypercholesterolemia psyllium, pectin or guar gum; and for obesity any supplement as tolerated.