Dietary fiber: The importance of dietary fiber in our bodies
Posted Oct 28 2009 11:00pm
Let's see what wikipedia says about dietary fiber
Dietary fiber (fibre), sometimes called roughage, is the indigestible portion of plant foods that pushes food through the digestive system, absorbing water and easing defecation. It acts by changing the nature of the contents of the gastrointestinal tract, and by changing how other nutrients and chemicals are absorbed.
Dietary fiber can be soluble (able to dissolve in water) or insoluble (not able to dissolve in water). Soluble fiber, like all fiber, cannot be digested. But it does change as it passes through the digestive tract, being transformed (fermented) by bacteria there. Soluble fiber also absorbs water to become a gelatinous substance that passes through the body. Insoluble fiber has bulking action but is mostly unchanged by fermentation as it passes through the body.
Chemically, dietary fiber consists of non-starch polysaccharides such as cellulose and many other plant components such as dextrins, inulin, lignin, waxes, chitins, pectins, beta-glucans and oligosaccharides. The term "fiber" is somewhat of a misnomer, since many types of so-called dietary fiber are not fibers at all.
Food sources of dietary fiber are often divided according to whether they provide (predominantly) soluble or insoluble fiber. To be precise, both types of fiber are present in all plant foods, with varying degrees of each according to a plant’s characteristics.
Potential advantages of consuming fiber are the production of health-promoting compounds during the fermentation of soluble fiber, and insoluble fiber's ability (via its passive water-attracting properties) to increase bulk, soften stool and shorten transit time through the intestinal trac t.