Jump to content

Glucomannan: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
Fixed typo
Tags: canned edit summary Mobile edit Mobile app edit
Totoro33 (talk | contribs)
351 edits
Grammar
Tags: Mobile edit Mobile web edit
Line 1: Line 1:
{{redirect-distinguish|Propolene|propylene}}
{{redirect-distinguish|Propolene|propylene}}
'''Glucomannan''' is a water-soluble [[polysaccharide]] that is considered a [[dietary fiber]]. It is a [[hemicellulose]] component in the [[Cell wall#Plant cell walls|cell walls]] of some plant species. Glucomannan is a [[food additive]] used as an [[emulsifier]] and [[thickener]]. Products containing glucomannan, under a variety of brand names, are marketed as nutritional supplements with false claims they can help weight loss. The [[Food and Drug Administration (United States)|U.S. Food and Drug Administration]] (FDA) has not approved any product containing glucomannan for the treatment of any medical condition and its use maybe harmful.
'''Glucomannan''' is a water-soluble [[polysaccharide]] that is considered a [[dietary fiber]]. It is a [[hemicellulose]] component in the [[Cell wall#Plant cell walls|cell walls]] of some plant species. Glucomannan is a [[food additive]] used as an [[emulsifier]] and [[thickener]]. Products containing glucomannan, under a variety of brand names, are marketed as nutritional supplements with false claims they can help weight loss. The [[Food and Drug Administration (United States)|U.S. Food and Drug Administration]] (FDA) has not approved any product containing glucomannan for the treatment of any medical condition and its use may be harmful.


==Chemistry==
==Chemistry==

Revision as of 14:23, 17 February 2018

"Propolene" redirects here. Not to be confused with propylene.

Glucomannan is a water-soluble polysaccharide that is considered a dietary fiber. It is a hemicellulose component in the cell walls of some plant species. Glucomannan is a food additive used as an emulsifier and thickener. Products containing glucomannan, under a variety of brand names, are marketed as nutritional supplements with false claims they can help weight loss. The U.S. Food and Drug Administration (FDA) has not approved any product containing glucomannan for the treatment of any medical condition and its use may be harmful.

Chemistry

Glucomannan is mainly a straight-chain polymer, with a small amount of branching. The component sugars are β-(1→4)-linked D-mannose and D-glucose in a ratio of 1.6:1.[1] The degree of branching is about 8% through β-(1→6)-glucosyl linkages.[2]

Glucomannan with α-(1→6)-linked galactose units in side branches is called galactoglucomannan.[citation needed]

Natural sources

Glucomannan comprises 40% by dry weight of the roots, or corm, of the konjac plant. Another culinary source is salep, ground from the roots of certain orchids and used in Turkish cuisine. Glucomannan is also a hemicellulose that is present in large amounts in the wood of conifers and in smaller amounts in the wood of dicotyledons.[citation needed] Glucomannan is also a constituent of bacterial, plant and yeast cell wall with differences in the branches or glycosidic linkages in the linear structure.[3][4][5]

Weight loss

Glucomannan is commonly sold as a weight loss aid, but medical research has found no good evidence to support its use for this purpose.[6][7][8]

Potential health risks

A health advisory was released by Health Canada stating the following: "Natural health products containing the ingredient glucomannan in tablet, capsule or powder form, which are currently on the Canadian market, have a potential for harm if taken without at least 250 ml or 8 ounces of water or other fluid. The risk to Canadians includes choking and/or blockage of the throat, esophagus or intestine, according to international adverse reaction case reports. It is also important to note that these products should not be taken immediately before going to bed."[9] The health advisory was issued after authorization of some products containing glucomannan for the purposes of appetite reduction, weight management, treatment of constipation and management of high cholesterol levels.[citation needed]

Consumer issues

Several companies selling products containing glucomannan have been disciplined by the U.S. Federal Trade Commission (FTC) for misleading or exaggerated claims pertaining to the health benefits of glucomannan supplements.[10]

Glucomannan is an ingredient in a variety of dietary supplement products marketed via television advertisements claiming to aid in weight loss. According to the FTC, there is no clinical data supporting many of the manufacturer claims and several companies have been determined by the Federal Trade Commission (FTC) or the Food and Drug Administration (FDA) to have, at some time, violated the Federal Food, Drug, and Cosmetic Act. The companies include Vitacost,[11] PediaLean,[12] Herbal Worldwide Holdings,[13] BioTrim,[14] and others. The company Obesity Research Institute, the marketer of FiberThin, Zylotrim, Propolene and Lipozene, settled FTC charges that their misleading weight-loss claims violated federal laws by agreeing to pay $1.5 million in consumer redress.[15]

In 2011, a number of jelly-type candy products containing konjac-derived glucomannan were barred from import by the US Food and Drug Administration due to choking hazards.[16]

Commercial use

Glucomannan is a food additive used as an emulsifier and thickener with the E number E425(ii).[17][18]

References

  1. ^ Kaname Katsuraya; Kohsaku Okuyamab; Kenichi Hatanakab; Ryuichi Oshimab; Takaya Satoc; Kei Matsuzakic (2003). "Constitution of konjac glucomannan: chemical analysis and 13C NMR spectroscopy". Carbohydrate Polymers. 53 (2): 183–189. doi:10.1016/S0144-8617(03)00039-0.
  2. ^ "Glucomannan: Uses, Side Effects, Interactions and Warnings".
  3. ^ Elbein, A. D. (1969). Biosynthesis of a cell wall glucomannan in mung bean seedlings. Journal of Biological Chemistry, 244(6), 1608-1616.
  4. ^ Tokoh, C., Takabe, K., Sugiyama, J., & Fujita, M. (2002). CP/MAS 13C NMR and electron diffraction study of bacterial cellulose structure affected by cell wall polysaccharides. Cellulose, 9(3-4), 351-360.
  5. ^ Chorvatovičová, D., Machová, E., Šandula, J., & Kogan, G. (1999). Protective effect of the yeast glucomannan against cyclophosphamide-induced mutagenicity. Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 444(1), 117-122.
  6. ^ Onakpoya I, Posadzki P, Ernst E (2014). "The efficacy of glucomannan supplementation in overweight and obesity: a systematic review and meta-analysis of randomized clinical trials". J Am Coll Nutr. 33 (1): 70–8. doi:10.1080/07315724.2014.870013. PMID 24533610.
  7. ^ Zalewski, Bartłomiej M.; Chmielewska, Anna; Szajewska, Hania (March 2015). "The effect of glucomannan on body weight in overweight or obese children and adults: a systematic review of randomized controlled trials". Nutrition (Burbank, Los Angeles County, Calif.). 31 (3): 437–442.e2. doi:10.1016/j.nut.2014.09.004. ISSN 1873-1244. PMID 25701331.
  8. ^ Allison, David B.; Zalewski, Bartłomiej M.; Chmielewska, Anna; Szajewska, Hania; Li, Peng; Goldsby, TaShauna U.; Keithley, Joyce K (2015). "Correction of data errors and reanalysis of "The effect of glucomannan on body weight in overweight or obese children and adults: A systematic review of randomized controlled trials"". Nutrition (Burbank, Los Angeles County, Calif.). 31 (7–8): 1056–1057. doi:10.1016/j.nut.2015.02.008. ISSN 0899-9007. PMC 4868090. PMID 26059384.
  9. ^ Health Canada Advises Canadians that Natural Health Products containing Glucomannan May Cause Serious Choking if Used with Insufficient Fluid, Health Canada Advisory
  10. ^ "Ads for Various Diet Supplements and Topical Gels Don’t Cut the Fat, Says the FTC". Federal Trade Commission
  11. ^ Food and Drug Administration letter
  12. ^ C. Landis Plummer (June 15, 2004). DOCKET NO. 9318 Archived 2008-05-13 at the Wayback Machine. Federal Trade Commission.
  13. ^ Federal Trade Commission complaint
  14. ^ Kovacic, William E.; Chun, Barbara Y.K. (November 3, 2004). "COMPLAINT FOR PERMTLNENT INJUNCTION AND OTHER EQUITABLE RELIEF". United States District Court for the Central District of California.
  15. ^ "FTC Settles Claims with Marketers of FiberThin and Propolene". Federal Trade Commission. June 20, 2005
  16. ^ "Import Alert 33-15, Detention Without Physical Examination of Gel Candies Containing Konjac" US FDA, Retrieved April 1, 2016
  17. ^ Current EU approved additives and their E Numbers, Food Standards Agency, 26 November 2010
  18. ^ "E425(ii) Konjac Glucomannan". CyberColloids. Retrieved January 25, 2013.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Glucomannan&oldid=826151449"