ABSTRACT
Plant fiber abounds in fruits, vegetables, legumes, and grains such as rice, wheat, rye, barley, oats, and corn. The most efficient sources are the cereal brans or outer husks of these grains. Scientists call the plant constituents which are resistant to digestion, as measured by the secretions in the human gastrointestinal tract, dietary fiber. Soluble fiber has high water-retention capacity and turns to gel during digestion. Pectins from fruits and vegetables, gums found in oat and rice bran, plus lentils, barley, cornmeal and seeds are examples of soluble fiber. Soluble fiber supplements have been shown to lower serum low-density lipoproteins, cholesterol levels. Soluble fibers have also been associated with improved sugar control in diabetics. The cellulose and lignin of insoluble fiber speed the passage of foods through the stomach to the intestines, providing bulk to the diet. The National Cancer Institute recommends 25–35 grams of total dietary fiber daily, yet, most Americans consume scarcely half this much.
