What is fibre?
Fibre is made up of the indigestible parts or compounds of plants, which pass relatively unchanged through our stomach and intestines. The main role of fibre is to keep the digestive system healthy. Other terms for dietary fibre include ‘bulk’ and ‘roughage’, which can be misleading since some forms of fibre are water soluble and aren’t bulky or rough at all. Fibre plays an important part in your digestive health and overall wellness. If you’re lacking in dietary fibre, your digestive system may not be working as well as it should and you may be at higher risk for serious health problems.
Fibre is largely a carbohydrate. The building blocks of all carbohydrates are different types of sugars and they can be classified according to how many sugar molecules are combined in the carbohydrate:
- Simple sugars – consist of 1-2 sugar molecules for example glucose, fructose, sucrose, maltose and lactose.
- Oligosaccharides – consist of 3-10 glucose molecules joined together.
- Starch polysaccharides – have more than 10 glucose molecules joined together.
- Non-starch polysaccharides – have more than 10 sugar molecules for example xylose, arabinose and mannose.
Millions of doses of laxatives we swallow each year wouldn’t be needed by most people if we ate more fibre. Consistent diarrhea, constipation, excessive wind, bloating, lethargy and stomach pain are all signs that your digestive system may be struggling to process the food you eat. Too much junk food and not drinking enough water add further stresses to your digestive system.
But getting everything working like clockwork isn’t the only reason to check your fibre intake. A high-fibre diet also has a role to play in protecting us from heart disease and even some cancers.
Besides keeping the digestive system in good health, fibre 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.
Where is fibre found?
Dietary fibre is found in wholegrains such as oats and barley, legumes, nuts, fruits and vegetables. Variety is the key when adding more fibre to your diet as all plant foods contain a mixture of soluble and insoluble fibres.
Foods that are highly processed, with loads of sugar and fat content usually contain very little, if any, fibre. This makes it easier to put on weight but can also lead to serious illnesses later in life. Regular intake of fibre can help prevent diabetes, heart disease, bowel cancer and diverticulitis – a small, inflamed pouch in the wall of the colon causing pain, diarrhea, constipation and other problems.
How much fibre should I eat?
Many Australians don’t consume enough fibre. On average, Australians consume 18-25g of fibre daily, and some have far less. The Heart Foundation recommends that adults should consume approximately 30g of fibre daily. As for children, Australian experts suggest 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. For children 8 years old and below, a minimum of 18g of fibre is required each day.
Disorders that can arise from a low fibre diet include:
- Irritable bowel syndrome
- Heart disease
- Some cancers including bowel cancer
Main types of fibre:
Fibre is made up of a number of components of plant foods that aren’t digested in the small intestine like other nutrients. However, fibre can be broken down to some extent by bacteria in the large intestine.
There are two main types: insoluble fibre and soluble fibre. A more recent addition to the fibre stable is resistant starch, while not traditionally thought of as ‘fibre’, has been found to act in a similar way. All plant foods — vegetables, fruit, legumes and grains — contain a mixture of fibres, and each type plays an important role in the body.
Insoluble fibre helps to keep you regular, it speeds the passage of foods through the digestive system adding bulk to the stool. Because insoluble fibre doesn’t break down, it can help relieve constipation.
This is the type of fibre you probably first think of — it’s important to prevent constipation and associated problems like haemorrhoids. It works by providing bulk to the diet and speeds everything through the bowel. It can also have an influence on the bowel bacteria, which may help prevent bowel cancer.
This type of fibre has started to get a reputation for preventing heart disease. It’s made up of things like pectin in fruit and gums in grains such as oats and barley, and legumes. It can lower cholesterol levels in the body and help with constipation, too. There’s usually much more insoluble fibre in plant foods than soluble so if you’re after a cholesterol-lowering effect, you need to take care to include high-soluble-fibre foods.
Soluble fibre helps to lower blood cholesterol levels, reduces the risk of heart disease and diabetes. It provides slow releasing energy for your body, keeping you feeling full for longer. Soluble fibre absorbs water in the digestive tract, making stools firmer and slower to pass, which can help in effectively treating IBS and mild cases of diarrhea.
Resistant starch is a third and recently discovered type of fibre, which helps to improve the digestive and intestinal health. It encourages the growth of healthy bacteria in the bowel and maintains healthy blood sugar levels.
Maintaining healthy bacteria in the bowel is beneficial to your health and well being as it increases your natural resistance to infections. Starch is found in many plant foods and has always been thought to be completely digested by the body’s normal digestive system. However, we now know that some starch doesn’t get digested and ends up as food for bacteria in the large intestine. It’s thought to act in a similar way to traditional fibre to improve bowel health. Resistant starch is in foods such as unprocessed cereals and grains, firm bananas, lentils, potatoes and especially in starchy foods that have been cooked then cooled (such as cold potatoes or rice). ‘Hi-maize’, added to foods such as some white breads and cereals, is also a type of resistant starch.
Getting more fibre:
It’s important to start off slowly when incorporating more fibre in your diet. If your body is not used to a high fibre diet, too much fibre can cause bloating and similar symptoms as not having enough fibre.
Give your body a chance to adapt and ease into it slowly. For starters, try replacing your breakfast with a high fibre cereal, like a BARLEYmax cereal, and see how you go. You can add more fibre rich foods as your body begins to adjust to the benefits of a high fibre diet.
A high fibre diet requires you to also drink plenty of water throughout the day. Fibre absorbs water to help waste material pass through your intestinal tract efficiently and relieves the feeling of bloating. Make sure you drink at least 8 glasses of water a day, to maintain the health of your digestive system.
For more information on BARLEYmax and fibre please download the BARLEYmax report.