Explain about the Dietary Fibre?
You are all aware that fibre is an important component in the structure of plants. However, fibre as a dietaiy constituent was considered important in the early 1970's when Burkitt and Trowell proposed that many western diseases were due to a lack of fibre in the diet. These included metabolic diseases such as diabetes, cardiovascular diseases, as well as, the diseases which were a result of straining at stool such as diverticular disease, hiatus hernia and haemorrhoids. Protective effects of fibre against colon cancer were also suggested by Burkitt.
Since then, extensive research has implicated dietary fibre as important in various aspects of gastrointestinal function and in prevention and management of a variety of disease states. The varying effects of dietary fibre as observed by researchers are obvious because it is made up of different components, each with its own distinctive characteristics. Methodologies have been developed to isolate these components, however, the definitions and methods of measuring fibre have changed over time. Let us see how definition of fibre has been modified over time.
Originally, Burkitt and Trowell defined fibre as 'the components of plant cell walls that are iitdigestible in the human small intestine'. Later the definition was expanded to include storage polysaccharides within plant cells also. Recently, the American Association of Cereal Chemists (AACC) developed an updated definition of dietary fibre to ensure that the term encompassed the complete characterization of the components, as well as, their function. The AACC along with the Carbohydrate Technical Committee of the North American branch of International Life Sciences Institute developed the definition as:
"Dietary fibre is the edible part of plants or analogous carbohydrates that are resistant to digestion and absorption in the human small intestine with complete or partial fermentation in the large intestine. Dietary fibre includes polysaccharides, oligosaccharides, lignin and associated plant substances. Dietary fibre promotes beneficial physiological effects including laxation and/or blood cholesterol attenuation and / or blood glucose attenuation."