ABOUT DIETARY FIBRE
Dietary fibre is important, even though our body can’t digest it! Fibre helps with normal bowel function, and may help lower blood cholesterol and regulate blood glucose. If a meal is eaten with fibre in it, it will delay and lessen the peak in blood glucose, helping with a more even blood glucose level. It gives a feeling of fullness without calories. Dietary fibre is found in whole grain breads and cereals, brown rice, fruit and vegetables.
Fibre is a form of carbohydrate that is indigestible and non-nutritive. It is a mixture of several compounds, and the proportion of these compounds in food varies.
Fibre is divided into two types: soluble and insoluble.
Dissolves in water
|Soluble fibre regulates the body’s use of sugars by slowing digestion and release into the bloodstream.
Soluble fibre helps to reduce cholesterol levels.
|Good sources of soluble fibre include –
Does not dissolve in water
|Insoluble fibre absorbs water and provides bulk in the diet. It helps to clear the intestinal tract.||Good sources of insoluble fibre include –
Whole grain flours
From the European Food Information Council (EUFIC):
Dietary fibre or ‘roughage’ comprises the edible parts of plant that cannot be digested or absorbed in the small intestine and passes into the large intestine intact. This includes non-starch polysaccharides (e.g. cellulose, hemicellulose, gums, pectins), oligosaccharides (e.g. inulin), lignin and associated plant substances (e.g. waxes, suberin). The term dietary fibre also includes a type of starch known as resistant starch (found in pulses, partly-milled seeds and grains, some breakfast cereals) because it resists digestion in the small intestine and reaches unchanged the large intestine.
Sources of dietary fibre
Dietary fibre is found in fruits (pears, strawberries, blackberries, raspberries, currants, oranges), vegetables (brussel sprouts, artichoke, onion, garlic, corn, peas, green beans, broccoli), pulses (lentils, chickpeas, beans) and wholegrains (all bran and oat bran cereals, whole and mixed grain breads).
Types of dietary fibre
Dietary fibre is often categorized according to its solubility into soluble or insoluble. Both types of fibre are found in different proportions in fibre-containing foods. Good sources of soluble fibre are oats, barley, fruit, vegetable and pulses (beans, lentils, chickpeas). Wholegrain cereals and wholemeal bread are rich sources of insoluble fibre.
Dietary fibre and health
Ingested dietary fibre moves along into the large intestine where it is partially or completely fermented by gut bacteria. During the fermentation process several by-products, short chain fatty acids and gases, are formed. It is the combined action of the fermentation process and the by-products formed that contribute the beneficial effects of dietary fibre on health.
- Bowel function
Dietary fibre, particularly insoluble fibre, helps prevent constipation by increasing stool weight and decreasing gut transit time. This effect is enhanced if fibre intake is paralleled by an increase in water intake.
The short chain fatty acids, produced when fibre is fermented by gut bacteria, are an important source of energy for colon cells and might inhibit growth and proliferation of gut tumour cells. By improving bowel function, dietary fibre can reduce the risk of diseases and disorders such as diverticular disease or haemorrhoids, and may also have a protective effect on colon cancer.
- Blood glucose levels
Soluble fibre, may slow digestion and absorption of carbohydrates and hence lower the rise in blood glucose that follows a meal (postprandial) and insulin response. This can help people with diabetes improve control their blood glucose levels.
- Blood cholesterol
Results of epidemiological studies identify another role for dietary fibre in the prevention of coronary heart disease (CHD) that of improving blood lipid profiles. Clinical trials confirm the results of these epidemiological studies. Isolated viscous fibres such as pectin, rice bran or oat bran lower both total serum cholesterol and low density lipoprotein (LDL or bad) cholesterol levels. At the same time, research continues to show that diets high in a mix of dietary fibre also protect against CHD.
While prevention of constipation, improved blood glucose levels, and blood lipid profiles predominate as beneficial outcomes of a diet high in dietary fibre, other benefits are worth noting. For example, because fibre provides bulk in the diet, without added calories, it can have a satiating effect on appetite; helping in weight management.
In order to have all the benefits of fibre it is important to vary the sources of fibre in the diet. Diets with fruits, vegetables, lentils/beans and wholegrains not only provide dietary fibre but as well many other nutrients and food components essential to good health.
How do I get some fibreWash and eat fruit with the skin on, make it a habit with breakfast
Eat plenty of fresh vegetables
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