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Nutritional Supplement

Glucomannan

  • Blood Sugar and Diabetes Support

    Metabolic Syndrome

    Taking a glucomannan fiber supplement may improve metabolic syndrome.
    Metabolic Syndrome
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    Glucomannan, a type of water-soluble dietary fiber from the root of the konjac plant, may reduce risk factors in people with metabolic syndrome. A double-blind trial found that 8–13 grams per day of glucomannan improved cholesterol levels and blood glucose control in people with metabolic syndrome.1 It is thought to work in part by acting as a prebiotic fiber, enhancing colonies of beneficial gut bacteria that participate in regulating metabolism.2 Even in patients with type 2 diabetes, 3 grams of glucomannan per day for four weeks improved blood glucose control and lipid metabolism compared to placebo.3

    Type 2 Diabetes

    Glucomannan delays stomach emptying, leading to more gradual glucose absorption and lower blood glucose levels after meals.
    Type 2 Diabetes
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    Glucomannan is a water-soluble dietary fiber derived from konjac root (Amorphophallus konjac) that delays stomach emptying, leading to a more gradual carbohydrate digestion and glucose absorption. Supplementing with glucomannan before eating has been shown reduce the post-meal elevation of blood glucose levels and long-term supplementation is associated with better blood glucose control and improvements in LDL-cholesterol levels in people with type 2 diabetes.4,5,6 Research in animals suggests glucomannan may be helpful in managing diabetes-related kidney dysfunction.7 Doses between 1 and 10 grams of glucomannan per day have demonstrated efficacy in clinical research.

    Hypoglycemia

    Glucomannan is a water-soluble dietary fiber. In one trial, adding glucomannan to a meal prevented hypoglycemia in adults with previous stomach surgery.
    Hypoglycemia
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    Glucomannan is a water-soluble dietary fiber that is derived from konjac root (Amorphophallus konjac). In a preliminary trial,8 addition of either 2.6 or 5.2 grams of glucomannan to a meal prevented hypoglycemia in adults with previous stomach surgery. A trial of glucomannan in children with hypoglycemia due to a condition known as “dumping syndrome” produced inconsistent results.9

    Type 1 Diabetes

    Glucomannan delays stomach emptying, leading to more gradual sugar absorption and possibly lowering insulin requirements for people with type 1 diabetes.
    Type 1 Diabetes
    ×
    Glucomannan is a water-soluble dietary fiber derived from konjac root (Amorphophallus konjac). Glucomannan delays stomach emptying, leading to a more gradual rise in glucose levels after eating carbohydrates. This could result in reduced need for insulin after meals in people with type 1 diabetes. In addition, glucomannan has positive effects on carbohydrate and fat metabolism, as well as the gut microbiota.10,11 These properties could lead to benefits in people with type 1 diabetes, but no research has been done to test this possibility.
  • Heart and Circulatory Health

    High Cholesterol

    Glucomannan is a water-soluble dietary fiber that has been shown to significantly reduce total blood cholesterol, LDL cholesterol, and triglycerides, and to raise HDL cholesterol.
    High Cholesterol
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    Glucomannan is a water-soluble dietary fiber that is derived from konjac root. Controlled12,13 and double-blind14,15 trials have shown that supplementation with glucomannan significantly reduced total blood cholesterol, LDL cholesterol, and triglycerides, and in some cases raised HDL cholesterol. Effective amounts of glucomannan for lowering blood cholesterol have been 4 to 13 grams per day.
  • Digestive Support

    Constipation

    Glucomannan is a water-soluble dietary fiber that has shown to be effective as a bulk-forming laxative.
    Constipation
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    Glucomannan is a water-soluble dietary fiber that is derived from konjac root. Like other sources of fiber, such as psyllium and fenugreek, glucomannan is considered a bulk-forming laxative. A preliminary trial16 and several double-blind trials17,18,19,20 have found glucomannan to be an effective treatment for constipation. The amount of glucomannan shown to be effective as a laxative is 3 to 4 grams per day. In constipated people, glucomannan and other bulk-forming laxatives generally help produce a bowel movement within 12 to 24 hours.

    Diverticular Disease

    Glucomannan is a water-soluble dietary fiber. One study found that people with diverticular disease had reduced symptoms after taking glucommanan.
    Diverticular Disease
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    Glucomannan is a water-soluble dietary fiber that is derived from konjac root (Amorphophallus konjac). A preliminary clinical trial found that approximately one-third to one half of people with diverticular disease had reduced symptoms of diverticular disease after taking glucommanan.21 The amount of glucomannan shown to be effective as a laxative is 3–4 grams per day.

  • Weight Management

    Obesity

    Supplementing with glucomannan, a bulking agent, has promoted weight loss in overweight adults.
    Obesity
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    Supplementing with 3 to 4 grams per day of a bulking agent called glucomannan, with or without calorie restriction, has promoted weight loss in overweight adults,22,23,24 while 2 to 3 grams per day was effective in a group of obese adolescents in another controlled trial.25
  • Children's Health

    Childhood Obesity

    Glucomannan, a type of fiber, dilutes calories, slows down the eating process, and may make people feel more full despite eating fewer calories.
    Childhood Obesity
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    Increased fiber intake is thought to have potential benefit in a weight-loss program since dietary fiber dilutes calories, slows down the eating process, and may make people feel more full despite eating fewer calories.26 However, research on using fiber in the treatment of childhood obesity has focused on using fiber supplements rather than comparing low- and high-fiber diets. Supplementation for four months with 2 to 3 grams per day of a bulking agent called glucomannan, was effective in a group of obese adolescents in one controlled trial,27 but another controlled trial found no significant effect of 2 grams per day for two months.28

What Are Star Ratings?
×
Reliable and relatively consistent scientific data showing a substantial health benefit.
Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

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References

1. Vuksan V, Sievenpiper J, Owen R, et al. Beneficial effects of viscous dietary fiber from Konjac-mannan in subjects with the insulin resistance syndrome: results of a controlled metabolic trial. Diabetes Care 2000;23:9–14.

2. Zheng J, Li H, Zhang X, et al. Prebiotic Mannan-Oligosaccharides Augment the Hypoglycemic Effects of Metformin in Correlation with Modulating Gut Microbiota. J Agric Food Chem 2018;66:5821–31.

3. Chearskul S, Sangurai S, Nitiyanant W, et al. Glycemic and lipid responses to glucomannan in Thais with type 2 diabetes mellitus. J Med Assoc Thai 2007;90:2150–7.

4. Chearskul S, Sangurai S, Nitiyanant W, et al. Glycemic and lipid responses to glucomannan in Thais with type 2 diabetes mellitus. J Med Assoc Thai 2007;90:2150–7.

5. Yoshida M, Vanstone C, Parsons W, et al. Effect of plant sterols and glucomannan on lipids in individuals with and without type II diabetes. Eur J Clin Nutr 2006;60:529–37.

6. Chen H, Sheu W, Tai T, et al. Konjac supplement alleviated hypercholesterolemia and hyperglycemia in type 2 diabetic subjects--a randomized double-blind trial. J Am Coll Nutr 2003;22:36–42.

7. Chen H, Nie Q, Hu J, et al. Glucomannans Alleviated the Progression of Diabetic Kidney Disease by Improving Kidney Metabolic Disturbance. Mol Nutr Food Res 2019;63:e1801008.

8. Hopman WP, Houben PG, Speth PA, Lamers CB. Glucomannan prevents postprandial hypoglycaemia in patients with previous gastric surgery. Gut 1988;29:930-4.

9. Kneepkens CM, Fernandes J, Vonk RJ. Dumping syndrome in children. Diagnosis and effect of glucomannan on glucose tolerance and absorption. Acta Paediatr Scand 1988;77:279-86.

10. Behera S, Ray R. Konjac glucomannan, a promising polysaccharide of Amorphophallus konjac K. Koch in health care. Int J Biol Macromol 2016;92:942–56.

11. Devaraj R, Reddy C, Xu B. Health-promoting effects of konjac glucomannan and its practical applications: A critical review. Int J Biol Macromol 2019;126:273–81.

12. Vuksan V, Jenkins DJ, Spadafora P, et al. 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;22:913-9.

13. Zhang MY, Huang CY, Wang X, et al. The effect of foods containing refined Konjac meal on human lipid metabolism. Biomed Environ Sci 1990;3:99-105.

14. Arvill A, Bodin L. Effect of short-term ingestion of konjac glucomannan on serum cholesterol in healthy men. Am J Clin Nutr 1995;61:585-9.

15. Walsh DE, Yaghoubian V, Behforooz A. Effect of glucomannan on obese patients: a clinical study. Int J Obes 1984;8:289-93.

16. Passaretti S, Franzoni M, Comin U, et al. Action of glucomannans on complaints in patients affected with chronic constipation: a multicentric clinical evaluation. Ital J Gastroenterol 1991;23:421-5.

17. Marzio L, Del Bianco R, Donne M, et al. Mouth-to-cecum transit time in patients affected by chronic constipation: effect of glucomannan. Am J Gastroenterol 1989;84:888-91.

18. Marsicano LJ, Berrizbeitia ML, Mondelo A. Use of glucomannan dietary fiber in changes in intestinal habit. G E N 1995;49:7-14 [in Spanish].

19. Signorelli P, Croce P, Dede A. A clinical study of the use of a combination of glucomannan with lactulose in the constipation of pregnancy. Minerva Ginecol 1996;48:577-82 [in Italian].

20. Staianno A, Simeone D, Giudice ED, et al. Effect of the dietary fiber glucomannan on chronic constipation in neurologically impaired children. J Pediatr 2000;136:41-5.

21. Papi C, Ciaco A, Koch M, Capurso L. Efficacy of rifaximin in the treatment of symptomatic diverticular disease of the colon. A multicentre double-blind placebo-controlled trial. Aliment Pharmacol Ther 1995;9:33-9.

22. Biancardi G, Palmiero L, Ghirardi PE. Glucomannan in the treatment of overweight patients with osteoarthritis. Curr Ther Res 1989;46:908-12.

23. Vita PM, Restelli A, Caspani P, Klinger R. Chronic use of glucomannan in the dietary treatment of severe obesity. Minerva Med 1992;83:135-9 [in Italian].

24. Walsh DE, Yaghoubian V, Behforooz A. Effect of glucomannan on obese patients: a clinical study. Int J Obes 1984;8:289-93.

25. Livieri C, Novazi F, Lorini R. The use of highly purified glucomannan-based fibers in childhood obesity. Pediatr Med Chir 1992;14:195-8 [in Italian].

26. Kimm SY. The role of dietary fiber in the development and treatment of childhood obesity. Pediatrics 1995;96:1010-4.

27. Livieri C, Novazi F, Lorini R. The use of highly purified glucomannan-based fibers in childhood obesity. Pediatr Med Chir 1992;14:195-8 [in Italian].

28. Vido L, Facchin P, Antonello I, et al. Childhood obesity treatment: double blinded trial on dietary fibres (glucomannan) versus placebo. Padiatr Padol 1993;28:133-6.

29. Marsicano LJ, Berrizbeitia ML, Mondelo A. Use of glucomannan dietary fiber in changes in intestinal habit. G E N 1995;49:7-14 [in Spanish].

30. Passaretti S, Franzoni M, Comin U, et al. Action of glucomannans on complaints in patients affected with chronic constipation: a multicentric clinical evaluation. Ital J Gastroenterol 1991;23:421-5.

31. Arvill A, Bodin L. Effect of short-term ingestion of konjac glucomannan on serum cholesterol in healthy men. Am J Clin Nutr 1995;61:585-9.

32. Vuksan V, Jenkins DJ, Spadafora P, et al. 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;22:913-9.

33. Vuksan V, Sievenpiper JL, Owen R, et al. Beneficial effects of viscous dietary fiber from Konjac-mannan in subjects with the insulin resistance syndrome: results of a controlled metabolic trial. Diabetes Care 2000;23:9-14.

34. Walsh DE, Yaghoubian V, Behforooz A. Effect of glucomannan on obese patients: a clinical study. Int J Obes 1984;8:289-93.

35. Vita PM, Restelli A, Caspani P, Klinger R. Chronic use of glucomannan in the dietary treatment of severe obesity. Minerva Med 1992;83:135-9 [in Italian].

36. Henry DA, Mitchell AS, Aylward J, et al. Glucomannan and risk of oesophageal obstruction. Br Med J 1986;292:591-2.

37. Werley MS, Burleigh-Flayer H, Mount EA, Kotkoskie LA. Respiratory sensitization to konjac flour in guinea pigs. Toxicology 1997;124:115-24.

Copyright © 2020 TraceGains, Inc. All rights reserved.

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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2020.

Copyright © 2020 TraceGains, Inc. All rights reserved.

The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2020.