Definition of Fiber

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Fiber: The parts of plants that cannot be digested, namely complex carbohydrates. Also known as bulk or roughage.

Complex carbohydrates from plants are rich in starch and fiber. Examples of plants that provide complex carbohydrates (fiber) are fresh fruits and vegetables, whole-grain breads, and cereal grains. Simple carbohydrates, such as common table sugar, have no fiber.

Dietary fiber can have many benefits including promoting bowel regularity, lowering the level of cholesterol in the blood, and easing conditions such as hemorrhoids, colitis, and diverticulosis. Dietary fiber can also aid in weight maintenance as it requires more chewing and promotes hunger satisfaction by giving the stomach a sense of fullness.

A salient benefit of dietary fiber was thought to be that it lowered the risk of colon cancer. Then in 1999 it was reported that dietary fiber seemed to have no effect on the chance of developing colon cancer. And in 2000 a kind of dietary fiber was discovered to increase the risk of the adenomas, the forerunners of cancer of the colon. The fiber under study was from ispaghula husk, which is not normally found in the diet but is found in laxatives containing mucilage. Ispaghula husk fiber is similar to psyllium, a fiber derived from plant husks that is found in many bulk laxatives. It appears that a high-fiber diet should be avoided by anyone who may have colorectal adenomas.