It is now an accepted medical fact that dietary fibre is necessary for the prevention of certain diseases. What is controversial is the question of how much and in what form.

Dietary fibre is made up of the constituents of plants which are resistant to digestion by the human gastrointestinal tract. Fibre increases the bulk of the faeces, it speeds the transit of bowel contents and is said to protect the body from the effects of cancer producing substances contained in some foods.

A diet high in fibre protects against cancer of the large bowel, diverticular disease, chronic constipation and associated haemorrhoids, appendicitis and the irritable bowel syndrome.

In diabetes it has become apparent that blood sugar levels are more easily controlled by the use of dietary fibre.

Fibre in the diet is said to lower the levels of cholesterol thus protecting against coronary artery disease. Oatmeal bran restricts the absorption of cholesterol - a convenient form is oatmeal porridge. Apparently wheat bran does not but it can replace some of the fat in the diet and have a beneficial effect indirectly.

Fruit and vegetables all play their part in protecting the heart. A mixed diet including fruits, vegetables, whole grain bread and cereal might be preferable to unprocessed bran which is said to interfere with the absorption of calcium, zinc and iron.

Some people find unprocessed bran unpalatable. Abdominal discomfort may be increased by excessive production of intestinal gas which produces abdominal swelling and flatulence. If deciding to take unprocessed bran it is wise to start with small amounts building up to 2 to 4 tablespoons per day.

Dietary Fibre is principally derived from plants. The main types of fibre are:

	Soluble: found in fruit, beans, food gums, oats
	Insoluble: found in cereals

and include substances such as cellulose, hemi-cellulose, lignin, pectin, mucillages and gums. Fibre in the diet is responsible for:

	Speed of transit of food breakdown products through the bowel
	Number, weight, consistency and water content of faeces
	Binding of the salts in bile
	Binding cholesterol
	Bacterial activity in the bowel

Generally speaking, Soluble Fibre is responsible for binding cholesterol and Insoluble Fibre on increasing faecal bulk and frequency. Fibre has also been implicated in a number of disease states,and increasing dietary fibre seeks to prevent some of these conditions:

	Diverticular Disease
	Hypercholesterolaemia, leading to heart disease and stroke
	Cancer of the colon
	Diabetes
	Irritable Bowel Syndrome
	Constipation
	Haemorrhoids
	Varicose Veins

High fibre intake can decrease the availability of other nutrients and some medication, but generally speaking our diets are oftenl acking in adequate amount of fibre. Recommended Daily Intake is 25-30 mg/day, and must be accompanied by adequate water intake.