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 non-calorie 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 breast-feeding 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 Web sites with general information on nutrition.


  1. Beer MU, Arrigoni E, Amado R. Effects of oat gum on blood cholesterol levels in healthy young men [see comments]. Eur J Clin Nutr. 1995 Jul;49(7):517-22.

  2. Pick ME, Hawrysh ZJ, Gee MI, Toth E, Garg ML, Hardin RT. Oat bran concentrate bread products improve long-term control of diabetes: a pilot study. J Am Diet Assoc. 1996 Dec;96(12):1254-61.

  3. Wu J, Peng SS. Comparison of hypolipidemic effect of refined konjac meal with several common dietary fibers and their mechanisms of action. Biomed Environ Sci. 1997 Mar;10(1):27-37.

  4. Taper HS, Delzenne NM, Roberfroid MB. Growth inhibition of transplantable mouse tumors by non-digestible carbohydrates. Int J Cancer. 1997 Jun 11;71(6):1109-12.

  5. Lia A, Andersson H, Mekki N, Juhel C, Senft M, Lairon D. Postprandial lipemia in relation to sterol and fat excretion in ileostomy subjects given oat-bran and wheat test meals. Am J Clin Nutr. 1997 Aug;66(2):357-65.

  6. Cameron IL, Hardman WE, Heitman DW. The nonfermentable dietary fiber lignin alters putative colon cancer risk factors but does not protect against DMH-induced colon cancer in rats. Nutr Cancer. 1997;28(2):170-6.

  7. Wursch P, Pi-Sunyer FX. The role of viscous soluble fiber in the metabolic control of diabetes. A review with special emphasis on cereals rich in beta-glucan. Diabetes Care. 1997 Nov;20(11):1774-80.

  8. Estrada A, Yun CH, Van Kessel A, Li B, Hauta S, Laarveld B. Immunomodulatory activities of oat beta-glucan in vitro and in vivo. Microbiol Immunol. 1997;41(12):991-8.

  9. Birt DF, Markin RS, Blackwood D, Harvell DM, Shull JD, Pennington KL. Dietary lignin, and insoluble fiber, enhance uterine cancer but did not influence mammary cancer induced by N-methyl-N-nitrosourea in rats. Nutr Cancer. 1998; 31(1):24-30.

  10. Negri E, Franceschi S, Parpinel M, La Vecchia C. Fiber intake and risk of colorectal cancer. Cancer Epidemiol Biomarkers Prev. 1998 Aug;7(8):667-71.

  11. Wilson TA, Behr SR, Nicolosi RJ. Addition of guar gum and soy protein increases the efficacy of the American Heart Association (AHA) step I cholesterol-lowering diet without reducing high density lipoprotein cholesterol levels in non- human primates. J Nutr. 1998 Sep;128(9):1429-33.

  12. Rao CV, Chou D, Simi B, Ku H, Reddy BS. Prevention of colonic aberrant crypt foci and modulation of large bowel microbial activity by dietary coffee fiber, inulin and pectin. Carcinogenesis. 1998 Oct;19(10):1815-9.

  13. Brown L, Rosner B, Willett WW, Sacks FM. Cholesterol-lowering effects of dietary fiber: a meta-analysis [see comments]. Am J Clin Nutr. 1999 Jan;69(1):30-42.

  14. Bell S, Goldman VM, Bistrian BR, Arnold AH, Ostroff G, Forse RA. Effect of beta-glucan from oats and yeast on serum lipids. Crit Rev Food Sci Nutr. 1999 Mar;39(2):189-202.

  15. Vuksan V, Jenkins DJ, Spadafora P, Sievenpiper JL, Owen R, Vidgen E, Brighenti F, Josse R, Leiter LA, Bruce-Thompson C. (1999 Jun). Konjac-mannan (glucomannan) improves glycemia and other associated risk factors for coronary heart disease in type 2 diabetes. A randomized controlled metabolic trial. Diabetes Care. 1999 Mar;22(6):913-9.

  16. Taper HS, Roberfroid M. Influence of inulin and oligofructose on breast cancer and tumor growth. J Nutr. 1999 Jul;129(7 Suppl):1488S-91S.

  17. Taper HS, Roberfroid M. Influence of inulin and oligofructose on breast cancer and tumor growth. J Nutr. 1999 Jul;129(7 Suppl):1488S-91S.

  18. Harris PJ, Ferguson LR. Dietary fibres may protect or enhance carcinogenesis. Mutat Res. 1999 Jul 15;443(1-2), 95-110.

  19. Knopp RH, Superko HR, Davidson M, Insull W, Dujovne CA, Kwiterovich PO, Zavoral JH, Graham K, O'Connor RR, Edelman DA. Long-term blood cholesterol-lowering effects of a dietary fiber supplement. Am J Prev Med. 1999 Jul;17(1):18-23.

  20. Shimizu J, Wada M, Takita T, Innami S. Curdlan and gellan gum, bacterial gel-forming polysaccharides, exhibit different effects on lipid metabolism, cecal fermentation and fecal bile acid excretion in rats [In Process Citation]. J Nutr Sci Vitaminol (Tokyo). 1999 Jun;45(3):251-62.

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