Dietary fiber is the part of a plant that provides and maintains the plant's structure. Cellulose, hemicellulose, polysaccharides, pectins, gums, mucilages, and lignins are dietary fibers. These fibers are unrelated chemically, however, they all have one thing in common -- they can't be digested by the human body. For this reason, they can help correct disorders of the large intestine (colon), and keep it functioning normally. Therefore, it is important to increase the amount of fiber in the diet.
Function of The Colon
The main job of the colon is to complete the digestion process. This occurs by removing excess water from food wastes entering from the small intestine. When wastes pass through the intestines too quickly, not enough water is absorbed. Watery stools and diarrhea are the result. In contrast, if the passage of waste is too slow, too much water is absorbed. This results in hard stools and constipation, which often leads to straining. These simple problems occasionally lead to more serious disorders.
The Importance of Dietary Fiber
Fiber (also called roughage or bulk) promotes the wavelike contractions that keep food moving through the intestine. Also, high-fiber foods expand the inside walls of the colon. This eases the passage of waste. Fibrous substances pass through the intestine undigested. They also absorb many times their weight in water, resulting in softer, bulkier stools.
Studies show that rural Africans, who eat diets high in fiber, eliminate food waste in one-third the time it takes people from urban westernized cultures. Their stools are larger and softer. Because of the greater bulk and speed of foods through the digestive tract, it is believed that harmful substances are also swept out before they can cause problems. In fact, these rural people have fewer of the digestive tract diseases that plague Western man. It is thought that this may be related to the nature of their diet.
A high-fiber diet causes a large, soft, bulky stool that passes through the bowel easily and quickly. Because of this action, some digestive tract disorders may be avoided, halted, or even reversed simply by following a high-fiber diet. A softer, larger stool helps prevent constipation and straining. This can help avoid or relieve hemorrhoids. More bulk means less pressure in the colon, which is important in the treatment of irritable bowel syndrome and diverticulosis (defects in the weakened walls of the colon). In addition, fiber appears to be important in treating diabetes, elevated cholesterol, colon polyps, and cancer of the colon.