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Dietary fibers and its health contributions

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@FP= Dietary fiber is commonly used for the treatment of various maladies of the gastrointestinal tract, such as constipation, diverticular disease, and irritable bowel syndrome. Fiber may also help in the management of diabetes. Diets that are high in fiber and digestible starches may be used to minimize the elevation of blood sugar that generally occurs after a meal. Theory on the evolution of the human diet collectively with comparative studies with the diet of other primates implies that the human gastrointestinal tract and metabolism are adapted to high fiber diets. Epidemiological studies have indicated that dietary fiber is a contributing factor in lowering the incidence of cancer of the colon. Colon cancer is the leading cause of cancer death in the United States. Increases in flow rate through the colon, generated by dietary fibers, reduce the levels of cancer-producing chemicals supplied directly by the diet, as well as those produced by microbial metabolism (Spiller and Kay 1980).

Dietary fiber and constipation

Constipation is the most common symptom noted among the elderly. It is defined as defecation less frequent that every third day. This potentially severe condition results from ignoring the urge to defecate. Impacted feces become awfully large, builds up and it becomes almost impossible to expel. Fiber is part of the management program of chronic constipation of the elderly. Addition of bran (6-20 grams/day) enlarges fecal weight and elevates the frequency of defecation (Vahouiny and Kritchevsky 1982).

Dietary Fiber and Diverticular Disease

Diverticular disease is caused by a weakness in the wall of the colon, and also internal pressure due to contractions occurring both upstream and downstream of the weak area. Half of the population above the age of fifty encounters such problems and the proportion increases as age increases (Dechmann and Cheskin, 1993). This disease presents severe abdominal pain, sometimes with painless bleeding from affected areas. Fiber comes to play an important role on preventing diverticular disease, because available evidence suggests that subjects on a low fiber diet are more prone to develop diverticluar disease. When patients with diverticular disease are treated with a high-fiber diet, the symptoms are effectively relieved and the abnormally high intraluminal pressures with in the sigmoid colon are reduced (Spiller and Kay 1980). Fruit and vegetables are believed to prevent the disease from happening, while cereal fiber particularly from bran is used to decrease the symptom of existing diverticular disease (Adoori et al., 1994).

Dietary Fiber and Irritable Bowel Syndrome

Irritable bowel syndrome is not a distinct disease, but it is a collection of symptoms. Irritable bowel syndrome is common in the young and middle aged, involves severe abdominal pain, nausea and vomiting, and rock-hard feces. Fiber may or may not be effective in improving the course of this disease. Altered patterns include constipation and some times diarrhea. The feces may look like hard marbles due to extensive water removal during constipation. Fiber (12-16 grams of bran a day) is used to treat the constipation, while other drugs are used to treat the diarrhea and spasms.

Dietary Fiber and Diabetes

Fiber may help in the management of diabetes. Diets that are high in fiber and digestible starches may be used to reduce the rise of blood sugar that generally takes place after a meal. In some patients, diets that furnish 50-60% of the body energy from theses carbohydrates result in improvement in the clinical picture, that is, they pick up the control plasma glucose levels and lessen the necessity for injected insulin. The soluble fibers used in these diets are supplied by guar gum, wheat bran, and apples.

Dietary Fiber and Colon Cancer

Varieties of Epidemiological studies have pointed out that dietary fiber is a contributing feature in lowering the occurrence of cancer of the colon. Colon cancer is the leading cause of cancer death in the United States. The increase in the size of material in the colon supplied by insoluble fibers has been thought to decrease the concentration of chemicals in the colon that advance the conversion of a normal colonocyte to a cancerous one. An enhanced flow rate through the colon, generated by dietary fibers, would reduce the time of exposure of the colonocytes to these chemicals. These effects should reduce the levels of cancer-producing chemicals supplied directly by the diet, as well as those produced by microbial metabolism.

Conclusion

It is now broadly acknowledged by health care officials that dietary fiber plays an important role in preserving good health in the population and enhanced in its consumption by Western populations is sought-after. Although many researches have shown the positive influence of dietary fiber and its metabolism, luck of knowledge of its mechanism of action has prevented wider acceptance of the therapeutic role dietary fiber plays in the treatment and prevention of disease. Besides the Scientifically proved studies on contribution to the treatment of the above mentioned diseases; more hindrance to a broader acceptance of dietary fibers include unpalatability, abdominal distension, flatulence and the high cost of prepared formulas. Nevertheless, dietary fiber’s aptitude in disease prevention and promoting health remains firm.

Reference:

Lloyd L.E., McDonald B.E. & Crampton E.W. 1978 Fundamentals of Nutrition. The

Carbohydrates and their metabolism. Pp 61-86. San Francisco: W.H. Freeman and Company

Vahouny V. G. & Kritchevsky D. 1982 Dietary Fiber in Health and Disease. Pp 133-139, 151-169, 237-239. New York and London: Plenum Press

Madar Z. & Odes H.S. 1990 Dietary Fiber Research. Pp 1-8. New York: KARGER

Brody Tom. 1999 Nutritional Biochemistry. Pp 140-147. San Diego: Academic

PressSpiller G.A. & Kay R.M. 1985 Medical Aspects of Dietary Fiber. Pp 43-61, 75-77, 193-194. New York & London: Plenum Medical Book Company