High-Fibre Diet

While the current American diet averages only about 10 grams of dietary fibre per day, intakes of 25 to 40 grams of fibre per day are linked to a reduced risk of developing a host of chronic diseases, including cancer, heart disease, and gastrointestinal conditions. High-fibre diets have also been suggested to protect against obesity.

Fibre falls into two general categories—water-soluble (found mostly in oats, fruit, and pulses) and water-insoluble (found mostly in grains and vegetables). As each type of fibre has different benefits, most people on high-fibre diets are generally advised to increase their intake of foods that feature both soluble and insoluble fibre.

Why do people follow this diet?

Some scientists believe that whole grains, containing high amounts of insoluble fibre, protect against several forms of cancer. In an analysis of the data from many studies, people who eat relatively high amounts of whole grains were reported to have low risks of lymphomas and cancers of the pancreas, stomach, colon, rectum, breast, uterus, mouth, throat, liver, and thyroid. Most research focusing on the relationship between cancer and fibre has focused on breast and colon cancers.

A diet high in fibre is protective against heart disease. Soluble fibre from beans, oats, psyllium seed, and fruit pectin has lowered cholesterol levels in most trials. Diets high in overall fibre have reduced triglyceride levels in several clinical trials, but have had no effect in others. Research suggests that soluble, not insoluble, fibres are helpful in lowering triglyceride levels. A high-fibre diet that features both soluble and insoluble fibres also seems to reduce the risk of both fatal and nonfatal heart attacks.

High-fibre diets also may be beneficial for certain gastrointestinal conditions. Fibre slows the movement of food and acidic fluid from the stomach to the intestines. It may help people with duodenal ulcers by reducing the exposure of the small intestine to stomach acids. Diverticular disease has become increasingly common and is thought to be due primarily to the consumption of a low-fibre diet; diets high in fibre have consequently been shown to protect against diverticular disease.

Preliminary evidence suggests that high-fibre diets also may benefit people with type 2 diabetes, as well people with chronic pancreatitis. More research is needed to confirm these relationships.

In addition to reducing the risk of certain chronic diseases, high-fibre diets may have other benefits. Fibre fills the stomach, thereby reducing appetite. Recent research has suggested that high-fibre diets may protect against obesity. Increased intake of fibre promotes digestive health and reduces constipation. Additionally, high fibre foods are generally rich in vitamins, minerals, and phytonutrients that are important for overall health.

Although people can be allergic to certain high-fibre foods (most commonly wheat), high-fibre diets are more likely to improve health than cause any health problems. Beans, a good source of soluble fibre, contain special sugars that are often poorly digested, often leading to flatulence (gas). Cooking beans with kombu (a type of seaweed) or using an enzyme supplement called alpha-galactosidase can help reduce this problem by improving digestion of these sugars.

Fibre reduces the absorption of most minerals. To minimise this effect, multimineral supplements should not be taken at the same time as a high-fibre meal.

What do I need to avoid?

Avoid food products made with processed grains, such as white flour or white rice, as they contain minimal fibre content.

Eat fresh fruits and vegetables, as opposed to drinking fruit and vegetable juices, since fibre is removed during the juicing process.

Best bets

Beans
Bran cereals
Flaxseeds
Fruits
Oat bran
Peanuts, walnuts
Psyllium seeds
Rye crisp crackers
Vegetables
Wheat bran
Wheat crisp crackers
Whole grain bread
Whole grains: wheat berries, barley, rye, bulgar, buckwheat
Whole-wheat pasta

Are there any groups or books associated with this diet?

High Fiber, High Flavor: Delicious Recipes for Good Health by Rosemary Moon, Toronto: Firefly Books, 2000.

The New Moosewood Cookbook by Mollie Katzen, Berkeley, CA: Ten Speed Press, 2000.

366 Delicious Ways to Cook Rice, Beans, and Grains by Andrea Chesman, New York: Plume, 1998.

The Corinne T. Netzer Fiber Counter by Corinne T. Netzer, New York: Dell Books, 1994.

Bibliography

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The information presented in the Food Guide is for informational purposes only and was created by a team of US–registered dietitians and food experts. Consult your doctor, practitioner, and/or chemist for any health problem and before using any supplements, making dietary changes, or before making any changes in prescribed medications. Information expires March 2007.

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