The main function of fibre is to keep the digestive system healthy and functioning properly. Fibre aids and speeds up the excretion of waste and toxins from the body preventing them from sitting in the intestine or bowel for too long and creating a build-up of toxins.
The 2 main types of fibre are:
Water-insoluble fibre
Water-soluble fibre
Fibre passes through the body virtually unchanged along with other digested food until it arrives at the large intestine. What happens next depends on the type of fibre present.
Insoluble fibre
In the case of insoluble fibre, it promotes the growth of a certain friendly bacteria that ferment and make the waste material soft and bulky. This in turn helps the waste to pass through the intestines quicker to the bowel and out of the body.
Insoluble fibre prevents constipation by adding bulk and liquid to aid movement and promote regular bowel movements. A larger and softer stool is able to pass through the intestines and bowel more easily and fluidly and is easier to evacuate.
As waste material passes through the body quickly and does not stay in the intestines or bowel for very long, toxins are not able to build up and accumulate. This is important in the prevention of distressing diseases such as bowel cancer or other cancers, constipation, irritable bowel syndrome, haemorrhoids and diverticulitis.
Insoluble fibre can be found in foods such as bran, wholemeal flour and breads, brown rice, whole grain cereals, vegetables, edible peels of fruit, nuts and seeds.
Soluble fibre
Soluble fibre absorbs water in the intestine, which softens the stool and helps the waste material move through the body more quickly.
It is thought that soluble fibre may help to reduce the level of cholesterol in the blood. This is due to the fact that soluble fibre binds the cholesterol from food or from bile acids preventing it from being absorbed into the bloodstream. This is then eliminated as waste, as the fibre cannot be digested.
Soluble fibre also slows down digestion and the sudden release of energy especially from carbohydrates into the bloodstream. This means that blood sugar levels are more stable, which is good for people with diabetes. Energy or glucose is released slowly and steadily, preventing sudden feelings of tiredness, lack of energy or hunger pangs.
Soluble fibre-rich foods include fruits, vegetables, lentils, peas, beans, oats, barley, oatmeal, potatoes, dried fruit, soya milk and soya products.
Eating a diet that does not contain enough fibre can lead to bowel irregularities and stomach discomforts. Foods that contain no or little fibre include refined cereals and white bread, meat and animal products, dairy produce and fast foods.