Fibre
Grandmothers have been extolling the health benefits of roughage for generations, insisting we eat lots to stay regular. But something called roughage hardly sounds appetising. Health professionals now refer to it as dietary fibre, and it appears grandma was right, fibre does help prevent constipation. In fact fibre may have even more health benefits than originally thought.
What is dietary fibre?
Dietary fibre is the structural part of plant foods that cannot be broken down in the small intestine and enters the large intestine undigested. In the large intestine some of the fibre is broken down by bacteria and the rest helps move the remaining waste out of the body.
There three basic types of dietary fibre.
- Soluble fibre – this component dissolves in water to form a gel, making waste material larger, softer and easier to move through the digestive system. It also slows down glucose absorption so helps to control blood sugar in people with diabetes and is beneficial to help lower blood cholesterol levels. Soluble fibre is found in fruits, vegetables, dried peas, soybeans, lentils, oats, rice and barley.
- Insoluble fibre – this component does not dissolve in water and as a result it’s ‘bulking properties helps keep us ‘regular’. Foods containing insoluble fibre include wholegrain and wholemeal breads, cereals and pasta. It is also in fruit and vegetables.
- Resistant starch - is a type of starch found in plant foods that escapes digestion in the small intestine. Resistant starch may provide similar benefits to other types of fibre, such as helping to prevent constipation. Foods containing resistant starch include; firm bananas, potatoes, legumes and cornflakes.
What are the health benefits of fibre?
Think of fibre as a tool for exercising the intestinal tract muscles, which are required to move food wastes through our gut. If we have a consistently low-fibre intake, these muscles become slack and cannot move food through our gut as they should. This can result in constipation and associated health issues.
Along with relieving constipation and maintaining GI (gastro intestinal) health, a diet high in fibre may also have the following health benefits:
- Not only does the bulky nature of fibrous foods leave us feeling fuller they are also typically slower to be absorbed from the small intestine. This results in prolonged feelings of satiety which helps with weight control. Additionally high fibre foods tend to be lower in calories than foods containing less fibre, because they are generally lower in fat.
- High fibre foods such as wholegrain cereal and bread are associated with lower prevalence rates of cardiovascular disease.
- High fibre foods such as fruit, vegetables and wholegrains tend to contain high levels of vitamins and antioxidants, which have been linked to lower incidences of many types of cancers.
- In individuals who eat high levels of fibre there is a reduced risk for developing diabetes. Increasing fibre intake in those with existing type-2 diabetes can help manage blood glucose control.
- A diet high in fibre reduces the likelihood of developing diverticular disease and hemorrhoids.
Good food sources of fibre
The recommended fibre intake per day for an adult male is 30g and adult female is 25g. The level of dietary fibre in a packaged food is shown on the nutrition panel. Simply look at the value in the ‘per serve’ column to determine how much fibre is in each serve.
The best way to get enough dietary fibre is to regularly eat wholegrain or wholemeal breads and cereals, legumes (such as kidney beans, soybeans and lentils), fruit, vegetables, nuts and seeds.
- Choose wholegrain breads and cereals, brown rice, wholemeal pasta and wholegrain crackers.
- Add legumes such as baked beans, kidney beans, lima beans, soybeans, chickpeas, dried peas and lentils to soups, casseroles and salads.
- Sprinkle chopped fresh or dried fruits or seeds on breakfast cereal.
- Try a handful of dried fruit and nuts as a snack or add some nuts to a stir-fry.
- Instead of a milkshake, try a fruit smoothie made with a banana.
- Eat unpeeled fruits (eg apples and pears) and vegetables (such as potatoes) wherever possible - the skins are a valuable source of fibre.
- Where possible, choose to eat the whole fruit instead of just drinking the juice - the juice contains very little fibre.
- Instead of sour cream or cream cheese-based dips, try a spicy bean dip or some hummus.
- In general, look on the nutrition panel of food products and choose those which provide at least 1.5 grams of dietary fibre per serve.
- Ensure you drink plenty of fluids as soluble fibre needs water to work at its optimal level.