A high fibre diet prevents constipation and diverticular disease, and it reduces risk of cardiovascular disease and Type 2 diabetes. Vegetables, fruit and grain are healthy sources for dietary fibre, but many people also take fibre supplements to make sure they consume enough fibre on a daily basis. Choosing the right fibre can be confusing, as there are many on the market.
Dietary fibre sometimes isn't a fibre at all. It is the indigestible component of food. Fibre is categorised according to its action in the large intestine: viscous, soluble or fermentable. Viscous fibres dissolve in water to form a gel that provides bulk for stool in the colon. Soluble fibres dissolve in water, and they absorb water in the colon, also creating bulk. Some fibres ferment in the colon, providing food for healthy intestinal bacteria. More healthy bacteria means a better functioning colon.
Psyllium is made from the husks of psyllium seeds. It is soluble and viscous, forming a gel when it absorbs water, and it ferments in the colon, feeding healthy intestinal bacteria. Psyllium slows the passage of food through the stomach and intestines, and slows absorption of nutrients from food. It helps lower cholesterol, and normalises blood glucose and insulin. This helps to prevent Type 2 diabetes. Psyllium makes stool softer and bulkier, preventing constipation. It's also used to treat irritable bowel syndrome and diverticular disease.
Methylcellulose is found in the cell walls of plants, such as oat bran. Methylcellulose is soluble, so it absorbs water in the colon and provides bulk and softness, making stool easier to pass. It isn't viscous, and it doesn't ferment in the colon. Methylcellulose is inert in the intestines, passing through without being digested and absorbed. It is used to treat constipation, irritable bowel syndrome and diverticular disease, but because of its water-absorbing property it is also used sometimes to treat diarrhoea.
Psyllium is the main ingredient in Metamucil and Konsyl. Methylcellulose is the main ingredient in Citrucel. However, these ingredients can also be found in health food stores in bulk. If you want to take psyllium, you can find it in many forms in the health food store. The least expensive psyllium products are found in the bulk products aisle. Methylcellulose is found in the walls of plant cells. Oat bran is a good source, and is readily available at health food stores and many grocery stores.
Recommended Fiber Intake
For adults younger than 50 years of age, the recommended total fibre intake is 38 grams a day for men, and 25 grams a day for men. This includes dietary fibre and supplements. For adults older than 50 years of age, the recommended intake is 30 grams a day for men and 21 grams a day for women from all sources.