Dietary fiber is an important component of the diet. Fiber comes from plant materials that are not digested easily. It makes up what was referred to in the past as roughage. Dietary fiber is of two types:
- Insoluble fibers are mainly cellulose and plant wall products.
- Water-soluble fibers are pectins and gums.
It has been known for a long time that insoluble fiber helps to regulate bowel evacuation. Consumption of a high fiber diet decreases bowel transit time to approximately 24 hours. Unfortunately, the transit time for the average American is 72 hours or longer. Studies have shown that by decreasing constipation there is a decrease in diverticulosis and a decrease in colorectal cancer.
Soluble fiber binds to cholesterol and other lipids in the bowel. This has been shown to reduce the total cholesterol and especially LDL. When the diet contains at least 15.9 grams of fiber daily there is a 12% lower risk of coronary artery disease and an 11% decrease in cerebrovascular disease.
Eating high-fiber foods is better than adding fiber to foods. Choose foods that are high in fiber:
- Whole fruits over juices. Whole wheat over processed white flour. Fresh vegetables and fruits over canned.
- Pectin is found in fruits and vegetables, especially apples, oranges, strawberries and carrots.
- Gums are found in oat bran, barley and legumes.
- Whole-wheat flour, wheat bran and vegetables are good sources of cellulose.
