Fibre or "roughage" as it is also known, is essentially a carbohydrate and is only found in plants. It is found in the walls of the plant's cells and is the only part of the plant that cannot be digested by the human body. It adds bulk to foods and contributes to the "full feeling" after a meal.
It does not provide any nutrients but it is essential for a healthy digestive systemas it ensures regular bowel movements, prevents constipation, and can also help lower high blood cholesterol levels.
So, now that you know what fibre is. What does fibre do?
The main function of fibre is to keep the digestive system healthy and functioning properly. Fibre aids and speeds up the removal of waste and toxins from the body.This preventing them from lying in the intestine or bowel for too long as this could cause toxins to build-up, leading to disease!
Fibre passes through the body virtually unchanged along with other digested food until it arrives at the large intestine. What happens next depends on which type of fibre is present as there are two types of fibre – soluble and insoluble. Insoluble fibre passes through your digestive system undigested, whereas soluble fibre is broken down by bacteria in your large bowel.
In the case of insoluble fibre, it promotes the growth of a certain friendly bacteria that ferments and makes the waste material soft and bulky, which in turn helps it to pass through the intestines quicker to the bowel and out of the body.
Insoluble fibre prevents constipation, which consists of small, hard and dry faeces that are hard to pass, 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 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, which are made up of cholesterol, 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, and energy or glucose is released slowly and steadily, preventing sudden feelings of tiredness, lack of energy or hunger pangs.
Sources of Soluble Fibre
Soluble fibre-rich foods include fruits, vegetables, lentils, peas, beans, oats, barley, oatmeal, potatoes, dried fruit, soya milk and soya products.