4 June 2014

Cherish the fibre in your diet

By
Cherish the fibre in your diet

Dietary fibre is generally defined as plant material, mainly derived from plant cell wall that resists the action of digestive enzymes in the gut. They are present in whole cereals, pulses, legumes, vegetables, and fruits. Dietary fibres are commonly classified by its water soluble property into insoluble and soluble fibre.

Fruits and vegetables contain soluble fibre where as legumes, pulses contain insoluble fibre. Insoluble fibres are very slowly digested, absorbed and fermented by colonic bacteria producing fatty acid and gas in the gut. Legumes are called flatulence producers as they produce gas when consumed in appreciable amounts.

Properties of dietary fibre

  • Water holding capacity:
    Dietary fibres are sturdily hydrophilic and hold water in between their cells. Thus increasing the viscosity and gel forming capacity of fibre. This phenomenon may explain the delayed gastric emptying associated with ingestion of fibres. Gels also lubricate the stools.
  • Binding ability:
    Dietary fibre is capable of trapping bile acids, cholesterol, certain toxins in between them and eventually evacuating with the feces.
  • Bulking ability:
    Insoluble fibre such as cellulose and lignin are mostly unfermentable by the colonic microflora and increase faecal bulkb by their particle formation and water holding capacity.
  • Fermentablity:
    Soluble fibres are fermented by colonic bacteria and butyric acid is released which is much essential for Vitamin K production.
  • Therapeutic effects of fibre
  • Constipation :
    Water holding capacity and bulking capability of fibre serves to slow down gastric emptying and colonic transit time by increasing weight and volume of stool. Stool volume also widen the lumen of colon thereby decreasing intraluminal pressure. Thus help to alleviate constipation.

Reduces cholesterol level

Diets rich in fibre decrease the total serum cholesterol and low density lipo protein level. A lower cholesterol ratio is associated with lower risk of heart disease.

Diabetes Mellitus

Diets rich in fibre and complex carbohydrates slow the absorption of carbohydrates there by decreasing the rapid increase of sugar after a meal. They also obviate the need for insulin or oral hypo glycemic drugs.

Colon Cancer

Consumption of fibre rich foods increases the growth of the friendly bacteria while decreasing the growth of harmful Ecoli, clostridia, and bacteroids. Carcinogens are also excreted trapped between the fibre cells.

Obesity

Consuming a diet rich in fibre increases the satiety value, thereby giving a feeling of fullness and preclude from eating a heavy meal. Thus the average consumption of dietary fibre should be at least 25 – 40 g per day per person as suggested by American Dietetic association.


Image Credit: Flickr/ Robert Huffstutter

0 comments:

Post a Comment