Fibre

Fibre is the general name for certain carbohydrates - usually parts of vegetables, plants and grains - that the body can't fully digest. While fibre isn't broken down and absorbed like nutrients, it still plays a key role in good health.

There are two main types of fibre: soluble fibre (which dissolves in water) and insoluble fibre (which does not). Combined, they're called total fibre.

Fibre uses

A number of studies have found that a high intake of total fibre, from foods and supplements, lowers the risk of heart disease. The British Dietetic Association recommends eating more wholegrains and foods high in soluble fibre, such as pulses, oats, fruit and vegetables.  It says "Evidence is mounting that eating wholegrains regularly as part of a healthy diet and lifestyle may help to reduce the risk of many common diseases."  The BDA cites a 2000 study by researchers at the University of Kentucky which suggests heart diseases and type 2 diabetes may be up to 30% lower in people who regularly eat wholegrain as part of a low-fat diet and healthy lifestyle. The BDA also says a diet rich in wholegrains may help maintain a healthy weight and a healthy digestive tract by helping maintain regular bowel movements and promote growth of healthy bacteria in the colon.

Insoluble fibre adds bulk to stools. It helps curb constipation and diarrhoea, and may benefit people with IBS (irritable bowel syndrome. Many studies have been carried out on the link between fibre consumption and bowel cancer. A 2003 study published in The Lancet contradicted earlier, smaller studies in the US, Finland and Sweden which showed no link between the two. Cancer Research UK says the study found "that people can almost halve their risk of bowel cancer by eating twice as many cereals, fruits and vegetables."

The results are part of the European Prospective Investigation into Cancer and Nutrition (EPIC) which is an ongoing study into the dietary habits, lifestyle and genetic characteristics of more than 500,000 Europeans. Currently it is believed that a diet high in fibre could help lower the risk of bowel cancer.

Some studies suggest soluble fibre may lower cholesterol levels. Some experts believe soluble fibre, in particular, can help maintain healthy cholesterol levels by acting like a sponge to absorb cholesterol in the digestive tract. Some studies suggest high-fibre diets have also been associated with a reduced risk of type 2 diabetes. For instance, a 2006 Finnish study published in the journal Diabetologia, investigated high fibre diets, weight loss and diabetes prevention. It concluded high fibre and fat intake are significant predictors of weight loss and progression to type 2 diabetes in high risk subjects. Soluble fibre may also be useful in treating diabetes by slowing the absorption of carbohydrates, helping to improve blood sugar levels.

Since fibre is filling and has very few calories, high-fibre foods may also help with weight loss.