Are you getting enough dietary fiber?

Dietary fiber was forgotten was many years. Far from being just a good way to prevent constipation, nutritionists are discovering that dietary fiber has a number of other important roles.

Fiber fallacies

A number of notions relating to dietary fiber are false. The first myth is that dietary fiber is one substance. Just as there are different vitamins, each with quite distinct actions in the body, so there are various forms of dietary fibers which have different separate purposes. These are not yet fully understood but nutritionists are beginning to unravel the mysteries of the large intestines and discover what actually goes on in its murky depths.

The second myth is that unprocessed bran is synonymous with dietary fiber. Considering that is a reasonably unpalatable product, sales of unprocessed bran are remarkably high. It s success is undoubtedly due to the fact that it helps prevent constipation. However, this does not mean that it is ideal. Bran is a good source of some dietary fivers but is no substitute for some other valuable kinds of food. A substance in unprocessed bran called phytic acid can ‘tie up’ minerals such as iron, calcium and zinc so that they are unable to be absorbed by the body. Small quantities of bran will not have sufficient phytic acid for this is be t o significant, but regularly taking half a cup of ore over a large period can possible cause problems. If you suffer from constipation, one to two table spoons of unprocessed bran can be useful with being hazardous. However, other variety of cereals and grains should also be consumed and eaten along with plenty of fruits and vegetables to provide a better balance of fiber.

A third myth is that fiber is ‘roughage’ which goes in one end of the body and emerges undigested sometimes later from the other end. By this definition, dietary fibers is not digested by the enzymes in the digestive juices in the stomach and small intestine. But it certainly does undergo digestion by bacteria in the large intestine. Rather than passing through us, much of the dietary fibers we eat are actually absorbed by the body.

Digestion of dietary fiber

The large bowel is where most of the digestion of dietary fibers occur. An army of bacteria (good ones) are set to work on different types of fiber and break them down, producing valuable chemical substances in the process. These substances are then absorbed and they play a vital role in regulating the levels of cholesterol and glucose in the blood. The acids produced are acetic, propionic and butyric. They are absorbed directly through the wall of the bowel, providing nourishment to the cells of the bowel wall.

These types of dietary fiber which are soluble in water are almost entirely digested by bacteria. These types of fiber produce more of the valuable volatile fatty acids. Rolled oats (porridge) and legumes both contain a high percentage of gummy types of dietary fiber which are thoroughly digested and help to control levels of cholesterol and glucose in the body.

The physical condition of some foods is also important. Coarse bran absorbs lots of water and will pass through the large intestine faster than finely ground bran.