Fiber exists in soluble, semi-soluble, and insoluble forms. Insoluble fibers are those for which humans lack digestive enzymes, and therefore, do not break down significantly in our digestive tracts. Cellulose from grain bran, some parts of fruits and vegetables, and lignin from legumes are insoluble fibers. These fibers provide roughage to insure bowel movements.
Soluble fibers, which do break down under the action of our digestive enzymes, include pectins and gums (mucilages). About a third of the fiber in fruits, vegetables, and many legumes is soluble. Some grains, such as oats and barley, contain large amounts of soluble fibers. These are considered to be highly desirable fibers. Pectins have long been known to promote wound healing, to slow the absorption of glucose from the intestines into the bloodstream, to bind a number of toxic chemicals thus preventing their absorption, and to aid in the reduction of cholesterol levels through the binding of bile acids.
Hemicellulose has qualities of both insoluble and soluble fibers. Psyllium husks, the dried seed coat of the Indian native Plant agoovata, is perhaps the best of these. It acts as roughage and absorbs and removes toxins from the intestines. It also moistens and soothes irritated intestinal membranes.
Fiber Aids Weight Loss
It is now recognized that the addition of fiber to the diet, especially soluble and semi-soluble fibers, offers many health benefits. Mixtures of sources of fibers of various types can be designed to work together synergistically to maximize their health-promoting properties. They act to regularize bowel functions, including the control of both diarrhea and constipation, to soothe irritated mucous membranes in the gastrointestinal tract, and to absorb various toxins and bacteria, which are then eliminated with the help of the bulking action of the fibers.
Emphasis upon the role of fiber in weight loss has once again become a topic of interest at the beginning of the twenty-first century because of the relative failure of reduced-fat diets to produce the hoped-for results. The bulk of the fiber itself gives a physical sensation of fullness that helps to control how much is eaten at a given meal. Whereas appetite is reduced directly by the bulk of the fiber, it is reduced indirectly through the delayed emptying of the stomach. Slowing the rate that the stomach empties gives the brain a better chance at receiving a satiety signal.
Individuals suffering from Syndrome X benefit from the fact that the bulking action of soluble fibers significantly slows the release of carbohydrates into the blood from the intestines. This avoids, as well, both the energy lows and the surges in appetite that characterize the body’s responses to excessive insulin release.
Just how important is dietary fiber in controlling weight? One study found that lean individuals eat about 50 percent more fiber than do those who are either moderately or severely obese. The amount of fiber in the diets of the three groups was estimated to be 18.8 grams versus 13.3 grams versus 13.7 grams, respectively. Other significant roles for fiber include the lowering of total cholesterol and the reduction of the incidence of colorectal cancer.
People who consume the most fiber have 47 per¬cent less colorectal cancer and 66 percent less pancreatic cancer than those who eat the least fiber. Since colon cancer ranks just behind lung cancer as a cause of death, the protection afforded by fiber against this particular cancer is of considerable importance.
The preferred sources of fiber are the soluble and semi-soluble varieties. Pectin, guar gum, oat bran, barley, and psyllium seed husks are such sources. Some of the new fiber products made from citrus sources may also come under this heading of preferred fibers. Whole foods can supply significant amounts of fiber. Oats, barley, oat bran, and various legumes can be added to the diet on a regular basis to supply sufficient quantities of these fiber groups. However, if this is not possible, the more concentrated of these fibers are available in tablets, capsules, and powdered/granulated forms. Tablets/capsules or granules/powders can be taken an hour before meals. These dosages should always be taken with at least eight or more ounces of water or serious dehydration can result.
Two special fiber sources are often promoted for weight loss and blood sugar control. Fenugreek (Trigonella foenum-gracum) is a traditional plant that recently has become the focus of attention largely because of a fiber derived from the seeds. Although there are some benefits from unique saponins found in the seeds, the blood sugar regulating effect of fenugreek seeds in clinical studies is likely mostly due to the inhibitory effects on glucose absorption from the intestines. Results in diabetics have been promising.
Another item sometimes used is nopal cactus (Opuntia streptacantha Lemaire). The exact mechanism by which nopal decreases blood glucose is unknown, but it is a good source of fiber and pectin. It is believed to act primarily by decreasing glucose absorption in the gastrointestinal tract when consumed in fairly significant quantities.
* Fenugreek seed fiber concentrate: 3-5 grams daily in food or water
* Nopal cactus concentrate: 500-1,000 mg taken with each meal
* Psyllium husks: 1-2 tablespoons once or twice daily in water
* Flax fiber: 1-2 tablespoons once or twice daily in water
* Modified citrus pectin: 1 tablespoonful once or twice daily in water
Fiber may bind nutrients and medications. Therefore, supplemental fiber should be taken at meals that do not include vitamin, mineral, or other nutritional supplements. Alternatively, the fiber should be consumed well before meals. Plenty of water should always be taken with dried fiber sources.