What Is It?
Most foods contain a mixture of soluble and insoluble fiber, which together make up the dietary fiber family. Compounds that dissolve or swell when put into water are called soluble fibers and include pectins, gums, mucilages, and some hemicelluloses. These compounds are found inside and around plant cells and exist as gum arabic, guar gum, locust bean gum, and pectins. Soluble fiber is found in cereals and a variety of foods such as salad dressings, jams, and jellies.
Soluble fibers eaten in high amounts can decrease blood cholesterol. If oat bran is used, the amount required would be approximately 80 to 100 grams per day which is about 3/4 cup of uncooked oats. With cooked beans, about 1 1/2 cups is needed, which is about 150 grams.
A diet high in soluble fiber is beneficial for several reasons. Soluble fiber ingested in large amounts can decrease blood cholesterol. The mechanism is due, in part, to the ability of soluble fiber to inhibit bile recycling in the intestinal tract. Bile, which is formed from cholesterol, is pulled into the feces for elimination, rather than eventually accumulating in the blood.
Soluble fiber is also beneficial in moderating levels of blood glucose. When consumed in large amounts, soluble fiber slows glucose absorption from the small intestine. The fiber, such as oatmeal, is processed slowly and produces a slow increase in blood glucose after eating. This effect may be helpful in the management of diabetes because it is part of a diet that helps to regulate blood glucose.
Additionally, study results suggest that soluble fiber can help delay gastric emptying, which may be useful in preventing overeating because it causes a feeling of satiety.
David Edelberg, MD