Why do we need dietary fibres?

Doctors and nutrition specialists recommend people of all ages to consume more dietary fibres. Research suggests that fibres help prevent cancer, diabetes, heart disease, obesity and other diseases.

What are dietary fibres?

Fibres are not a single food or substance. The human body cannot absorb fibres that have no calories in themselves.

As they are carried through the digestive system and out of the body, fibres maintain health and lower the risk of numerous diseases and conditions, including colorectal and other types of cancer.

What is the source of dietary fibres?

Plants are the unique source of dietary fibre because of the polysaccharide structure of their cell wall, as well as the storage and secretion polysaccharides associated with plant cells and seeds.

Dietary fibres and gastrointestinal function

Dietary fibres are clearly important for normal gastrointestinal function. This role is well defined in the large intestine, where dietary fibres provide bulk and substrates for microbial activity. Several investigators have proposed that the adequacy of fibres intake can be determined by estimating the amount of fibre needed to maintain an adequate stool weight and transit time.

The general health effects of fibres

Fibres that you eat affect your digestion in several ways. Fibres help move food and digestive by-products efficiently through the large intestine (colon) and out of the body.

The faster food and digestive by-products pass through the gastrointestinal tract, the less time there is for potential cancer-causing agents to do their damage. Fibre is also thought to dilute potential carcinogens, thus lessening their impact. It also helps to alter the metabolism of certain bacteria in the digestive tract, thereby promoting a healthy digestion.

A high-fat diet increases the amount of bile acids and bacterial enzymes in the colon, where bacteria can convert them to cancer-causing chemicals. Increasing the quantity of fibre in the intestines helps to reverse this effect by diluting or inactivating the chemicals and reducing the level of bile acids and bacteria.

Dietary fibres and food transit

Another important function of fibres is to quicken the excretion of wastes and their cancer-causing by-products so that they will leave the body before they have much time to come in contact with the sensitive cells which line the inner walls of the bowel. In a typical diet, food needs three or more days to pass through the bowel. Eating even less fibre can allow food to remain in the body still longer. With a high-fibre diet, food is eliminated within a day or two.

How much dietary fibres does food contain?

Fresh fruit is often considered to be the best source of dietary fibres. Comparing 100g of each of these fruits to the same amount of Sankom:

•  Apple 2.1 g
  
•  Banana 1.3 g
  
•  Peach 1.4 g
  
•  Sankom Dietary Fibres: 16 g.