Dietary Fibers

Like its fellow carbohydrates, the various types of dietary
fiber are the product of sunlight, water and carbon dioxide
combining in green plants. Most form part of plant cell
walls. But unlike the other carbohydrates, fibers do not
break down into sugars in the human digestive system and
then course through the blood stream fueling muscles and
nerves. Rather, when eaten they tumble intact through the
stomach and small intestine and end up in the colon where
billions of bacterial feed on them - in turn producing
intestinal gas. No wonder, then, that dietary fiber has
been unwelcome in many of history's nicer neighborhoods.
 
Even 20th century doctors reasoned that since the bulky
material provided not a single nutrient, it would only
strain already troubled guts. Accordingly, they recommended
low-fiber diets for patients suffering from hemorrhoids and
other colon disorders often found in the West. But then,
about 15 years ago, the prescription was reversed as
researchers found that poor Africans, who eat lots of
fiber, rarely suffer from such complaints. Fiber, the
researchers learned, actually eases the bowel's burden by
mixing with water and other food residues. 

Soon, nutritionists came to see the low-fiber diet of most
North Americans as a culprit in the onset of disorders
ranging from tooth decay to heart attacks. Increasing the
consumption of certain kinds of fiber, they found, could
slow the body's absorption of sugars to which diabetics are
sensitive, and of cholesterol, which may lead to heart
disease.
 
Furthermore, fibers fight obesity. They're filling,
especially the pectins in citrus fruit and the gums in some
beans. They're mainly indigestible, therefore, dieters
eating lots of fiber are likely to eat less of other, more
fattening foodstuffs.
 
As for why populations on high-fiber diets seem to
experience fewer colon cancers, no one knows for sure. In
any case, there is no doubt that fiber is nature's
laxative, the dietary key to regularity. Nutritionists
therefore advise you to stay away from foods containing
processed and refined ingredients such as bleached flour
and white sugar. Remember that meats contain little fiber
and that overcooked vegetables and fried foods have lost
much of theirs.
 
Nevertheless, fiber supplements are usually unnecessary. A
healthy diet should be full of fresh fruits and vegetables
- and some of the most fibrous foods such as bran cereals,
whole wheat breads, peas, beans and lentils.