Other name(s):

b-glucan, cellulose, chitosan, gellan, guar gum, gum, hemicellulose, konjac mannan, lignin, mucilage pectin

General description

Fiber is present to some degree in almost all plant species. In addition it is produced by marine life, insects, yeasts, fungi, bacteria, and a host of other organisms. Fiber is often referred to as soluble or insoluble, depending on whether it dissolves in water. Food sources include bran, whole grains, vegetables, fruits, and seaweed.

Current research suggests that fiber may be helpful in preventing colon cancer, treating diabetes, and controlling high blood pressure.

Medically valid uses

Fiber has been shown in multiple studies to reduce the incidence of cancer in the colon. Many studies, some going back more than 20 years and including cross-cultural and international studies, demonstrate that people and cultures whose diet consists largely of fruits and vegetables have a lower incidence of colon cancer than those whose diet contains large amounts of meat and animal fats.

Fiber is also used to:

  • Improve taste and texture in food

  • Improve retention of water in foods

  • Prevent constipation

  • Provide "body" in liquid medications

Fiber is also used as a noncalorie or low-calorie meat expander in foods such as hamburger, and as a low-calorie fat substitute. Fiber can also be used as a surgical dressing for wounds.

Unsubstantiated claims

Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.

Fiber is claimed to be useful in treating diverticulosis, elevated cholesterol, diabetes, and high blood pressure.

Dosing format

Women who are pregnant or breastfeeding should consult a physician before adding too much fiber to their diet.

Side effects, toxicity, and interactions

Some fibers can cause diarrhea; others cause constipation.

There are no known significant food or drug interactions associated with fiber.

Additional information

Click here for a list of reputable websites with general information on nutrition.

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