You may have heard that fibre is essential to a healthy digestive system, but there are many other health benefits associated with consuming adequate levels of soluble and insoluble fibre.
What is fibre?
There is no single definition of dietary fibre, which is found in all plant materials. It is made up of the indigestible parts or compounds of plants, which pass relatively unchanged through our stomach and intestines.
Fibre can be classified into two categories:
- Soluble fibre: the primary role of soluble fibre is to lower LDL cholesterol, it can also help ease constipation. Sources of soluble fibre include fruit and vegetables; oat bran; barley; dried beans, lentils and pulses; soy milk and soy products; flaxseed and psyllium.
- Insoluble fibre: the primary role of insoluble fibre is to add bulk to faeces and prevent constipation and associated problems. Sources of insoluble fibre include wheat, corn and rice brans; skins of fruit and vegetables; nuts; seeds; dried beans and wholegrain foods.
Resistant starch also acts in a similar way to fibre and is found in many unprocessed cereals and grains, unripe bananas, potatoes and lentils. It is important for maintaining bowel health.
Why do our bodies need fibre?
Fibre keeps the digestive system healthy, as it helps reduce blood cholesterol and regulates blood glucose levels. It has also been related to risk reduction for a number of chronic diseases such as heart disease, certain cancers and diabetes. It has been suggested that diets high in fibre have a lower energy density and may therefore help in moderating obesity however how these benefits arise has not been determined.
What are the recommendations for fibre intake?
Current recommendations are for men to consume 30g of fibre per day and for women to consume 25g of fibre per day, with small increases for pregnancy and lactation to allow for additional body weight and energy needs. Consuming natural sources of fibre, such as fruit and vegetables, is better for you than using fibre supplements.
As dietary fibre absorbs fluid, it is important to drink enough liquid, including water each day, especially when there is an increase in fibre in the diet.
What happens if we consume too much or too little fibre?
Most Australians do not consume enough fibre. Ensuring you are getting enough fibre in your diet can help to prevent constipation and other digestive problems.
Suddenly increasing the fibre content of your diet, may result in some abdominal pain and increased flatulence (wind). Very high-fibre diets are also linked with decreased absorption of some important minerals which could result in an increased risk of nutritional deficiencies in some people.