Importance of Fibre

What is Fibre?

Dietary fibre is found in vegetables, fruits and cereal. Fibre is made up of the indigestible parts or compounds of plants, which pass relatively unchanged through our stomach and intestines.

Dietary fibre is mainly needed to keep the digestive system healthy. It also contributes to other processes, such as stabilising glucose and cholesterol levels. In countries with traditionally high fibre diets, diseases such as bowel cancer, diabetes and coronary heart disease are much less common than in the West.


Dietary fibre can be divided into two distinct types:

1. Soluble fibre forms a gel-like material in water. It helps restore regularity and lowers cholesterol. Good sources include oats, beans, peas, many types of fruit, and psyllium.

2. Insoluble fibre does not dissolve in water and moves through your digestive system quickly and largely intact. Good sources include wheat bran, whole-grain cereals and breads, and many vegetables. The secret to getting enough fibre is to eat a well-balanced diet that includes a variety of high-fibre foods.


Why is Fibre important?

Fibre is a key component in maintaining everyday and long term health. The Heart Foundation recommends that adults should consume approximately 30g daily. Australian experts suggest that children should eat 10g of fibre a day plus an additional gram for every year of age. For instance, a 10 year old child should eat 15-20g of fibre per day.


Some scary truths:

• Most Australian adults do not meet their recommended daily fibre intake
• Average fibre consumption is just 18-25 grams a day, well below the recommended 30 grams.
• Australians are finding it increasingly difficult to get enough fibre from fruits, vegetables and wholegrain breads.

Both types of Fibre are beneficial to the body:

1. Fibre keeps the digestive tract healthy
The principle advantage of a diet high in fibre is the health of the digestive system. The digestive system is lined with muscles that massage food along the tract from the moment a mouthful is swallowed until the eventual waste is passed out of the bowel (a process called peristalsis). Since fibre is relatively indigestible, it adds bulk to the faeces.

Soluble fibre soaks up water like a sponge, which helps to plump out the faeces and allows it to pass through the gut more easily. It acts to slow down the rate of digestion. This slowing down effect is usually overridden by insoluble fibre, which doesn't absorb water and speeds up the time that food passes through the gut.

2. Lowering blood cholesterol
Recently, some studies showed that regular intake of foods high in soluble fibre - such as oat bran, baked beans and soybeans - reduced blood cholesterol levels. When blood cholesterol levels are high, fatty streaks and plaques are deposited along the walls of arteries. This can make them dangerously narrow and lead to an increased risk of coronary heart disease.

It is thought that soluble fibre lowers blood cholesterol by binding bile acids (which are made from cholesterol to digest dietary fats) and then excreting them. Cereal fibre seems to be more protective against coronary heart disease than the fibre from fruit and vegetables.

3. Direct link between Fibre intake and how well our immune system operates
Australian Immunology research lead by Professor Charles Mackay has identified how fibre in the diet plays a major role in ensuring a person's immune cells function properly.

4. Good for people with diabetes
For people with diabetes, eating a diet high in fibre slows glucose absorption from the small intestine into the blood. This reduces the possibility of a surge of insulin, the hormone produced by the pancreas to stabilise blood glucose levels.

5. Fibre and ageing
Fibre is even more important for older people. The digestive system slows down with age, so a high fibre diet becomes even more important.

6. A method of weight control
In many cases, people who are overweight or obese have been shown to lose significant amounts of excess body fat simply by increasing the amount of dietary fibre, especially soluble fibre, in their daily diet. Recent study reveals that fibrous foods are often bulky and, therefore, filling. They also tend to be low in fat.

Soluble fibre forms a gel that slows down the emptying of the stomach and the transit time of food through the digestive system. This extends the time a person feels satisfied or ?full?. It also delays the absorption of sugars from the intestines. This helps to maintain lower blood sugar levels and prevent a rapid rise in blood insulin levels, which has been linked with obesity and an increased risk of diabetes.

The extra chewing time often required of high fibre foods also helps contribute to feeling satisfied. As a result, a person on a high fibre diet is likely to eat less food and so consume less kilojoules (calories).


Conditions linked to low fibre diets:
Eating a diet low in fibre can contribute to many disorders, including:

• Constipation - small, hard and dry faecal matter that is difficult to pass.
• Haemorrhoids - varicose veins of the anus.
• Diverticulitis - small hernias of the digestive tract caused by long term constipation.
• Irritable bowel syndrome - pain, flatulence and bloating of the abdomen.
• Overweight and obesity - carrying too much body fat.
• Coronary heart disease - a narrowing of the arteries due to fatty deposits.
• Diabetes - a condition characterised by too much glucose in the blood.
• Colon cancer - cancer of the large intestine.

Ways to increase your fibre intake:
Simple suggestions for increasing your daily fibre intake include:

• Eat breakfast cereals that contain barley, wheat or oats.
• Switch to wholemeal or multigrain breads and brown rice.
• Add an extra vegetable to every evening meal.
• Snack on fruit, dried fruit, nuts or wholemeal crackers.

Kanten World Editor

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