All about fibre

The fibre in food helps keep your bowels (intestines) healthy and may protect against bowel cancer. It also helps control your weight, blood cholesterol level and blood sugar level. There are good amounts of fibre in wholegrain breads and cereals, fruits, vegetables, legumes, nuts and seeds. Ask a doctor, your local pharmacist or dietitian for advice.

What is fibre?

Fibre is found in foods that come from plants. It is also called ‘roughage’ or ‘bulk’. Dietary fibre is the part of plant foods that is not digested or absorbed in your stomach or small intestine. Dietary fibre passes unchanged into the large bowel (large intestine, colon), where bacteria break it down. The break-down of fibre may produce a lot of gas (wind) in the large bowel.

Most dietary fibres are carbohydrates. The main types of dietary fibre are soluble fibre, insoluble fibre and resistant starch.

Some foods with good amounts of soluble fibre are: oats, barley, rye, fruits, vegetables and legumes (e.g. beans, lentils).

• Some foods with good amounts of insoluble fibre are: wheat bran, rice bran, wholegrain foods, the skins of fruits and vegetables, nuts and seeds.

• Some foods with good amounts of resistant starch are: unprocessed wholegrain cereals, nuts and seeds, underripe bananas, legumes, slightly undercooked (“al dente”) pasta and cooked and cooled potato, rice and pasta. Resistant starch (as Hi-Maize) is added to some breakfast cereals and fibre supplement products.

Fibre and health

Some health benefits of a high fibre diet are:

• Fibre increases the size of faeces (bowel motions) and helps to soften them. Large, soft faeces move quickly and easily through your bowel, and are easy to pass when you empty your bowel.

• High fibre foods can help control body weight. They are often slow to eat (they need more chewing), they are filling, and they often contain less kilojoules (calories) per gram than low fibre foods.

• Soluble fibre slows the absorption of sugar into the blood stream. A high fibre diet can help people with diabetes control their blood sugar levels and may also reduce the risk of developing type 2 diabetes.

• Soluble fibre can help lower your blood cholesterol level.

• Fibre may reduce the risk of bowel cancer (colorectal cancer).

The breakdown of soluble fibre and resistant starch in the bowel produces short-chain fatty acids, which may protect the bowel from cancer. Also, large, soft faeces moving quickly and easily through the bowel can quickly remove cancer-causing substances from the bowel.

• High fibre foods usually contain many vitamins, minerals and other essential nutrients.

Effects of low fibre

A diet that is low in fibre may cause or worsen some health problems such as constipation, haemorrhoids (piles), bowel cancer, diverticular disease, irritable bowel syndrome, being overweight, high blood cholesterol and diabetes.

Self-care

• Eat a wide variety of high fibre foods. Most adults should aim to eat at least five serves of vegetables, two serves of fruit, 4-6 serves of wholegrain or wholemeal foods, and some nuts and seeds every day. Limit foods high in fat, sugar or salt.

• Increase fibre in your diet gradually, to avoid wind, bloating and cramping.

• Eat regular meals to help your bowel activity.

• Never ignore the urge to empty your bowels.

• Drink enough water every day to satisfy your thirst and to keep your urine ‘light-coloured’ (unless a doctor advises not to). A person with a high fibre diet needs to drink plenty of fluid, to avoid constipation

• Exercise at a moderate level for at least 30 minutes on all or most days of the week. Exercise can help your bowel activity.

Fibre supplements

The best way to get fibre is to eat high fibre foods. Some people also need to use fibre supplement products. The fibre in these products may produce less gas in the bowel than high fibre foods.

When using fibre supplements always follow the instructions carefully. The best way to get fibre is to eat high fibre foods. Some people also need to use fibre supplement products. The fibre in these products may produce less gas in the bowel than high fibre foods. When using fibre supplements always follow the instructions carefully. Fibre supplements must be taken with plenty of fluid, may reduce absorption of medicines and are best taken two hours apart from other medicines.

For further information ask a Piggott’s Pharmacist or doctor for advice.