Glucomannan is a natural, water-soluble polysaccharide extracted from the roots of Amorphophallus Konjac, also known as an elephant yam. It grows in warm subtropical and tropical eastern Asia, from Japan to South China to Indonesia.
Glucomannan has a unique ability to absorb water, up to 200 times its own weight, and it forms a very thick, gel-like mass. For example, if you empty a glucomannan capsule into a glass of water, it will “sponge” up water and everything will be turned into a gel. That is exactly why it’s recommended for those, who want to lose weight. It fills up the space in your stomach and you have a feeling of fullness¹ without leaving you gassy or bloated. It also delays emptying of the stomach, therefore reducing food intake in general. Moreover, it is very low in calories and reduces the absorption of protein and fat, like any other soluble fibers. It is very important to take it with a glass of water before meal to reduce the appetite.
Clinic studies showed a significant mean weight loss in obese people (up to 5.5 lbs lost) during an eight-week period with no adverse reactions.² Glucomannan has no odor or taste, so you can easily add it to any recipe that includes cornstarch.
Glucomannan relieves from constipation (regular or chronical) and improves the symptoms by decreasing fecal transit time in adults as well as children. Studies showed that in neurologically impaired children, glucomannan improves stool frequency but has no effect on colonic motility.³
This amazing ingredient also can lower the cholesterol level in men, women and children! In 2008, 14 studies with a total of 531 patients showed that glucomannan reduced overall cholesterol levels.4 Glucomannan's cholesterol-lowering effects have been evaluated in children as well. Clinical study of 40 children with hypercholesterolemia showed significant reduction in total cholesterol and LDL cholesterol values. Interesting thing was noticed during these studies, so called “gender difference”. Greater improvement in total cholesterol was observed in girls compared to boys.5
A large number of studies have consistently shown that glucomannan can decrease blood sugar in people with type 2 diabetes. It improves the lipid profile and alleviates the fasting blood glucose levels of type 2 diabetics. Glycemic index diets can increase the risk of heart disease and diabetes, but if you take glucomannan before or during a meal, it reduces the glucose and insulin response and effectively reduces this glycemic index.
Studies on mice also showed that glucomannan has a potential in treating lung cancer. Mice fed with konjaku powder showed a reduction in cancer rate from 70.87% in the positive control group to 19.38% in the group fed with konjac powder. Lung tumors were induced and study reported no adverse reactions to the konjaku powder.6
1 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. 2014;33(1):70-8.
2 Walsh DE, Yaghoubian V, Behforooz A. Effect of glucomannan on obese patients: a clinical study. 1984;8(4):289-93.
3 Staiano A, Simeone D, Del Giudice E, Miele E, Tozzi A, Toraldo C. Effect of the dietary fiber glucomannan on chronic constipation in neurologically impaired children. J Pediatr. 2000 Jan;136(1):41-5.
4 Sood N, Baker WL, Coleman CI. Effect of glucomannan on plasma lipid and glucose concentrations, body weight, and blood pressure: systematic review and meta-analysis. Am J Clin Nutr . 2008;88(4):1167-1175.
5 Martino F, Martino E, Morrone F, Carnevali E, Forcone R, Niglio T. Effect of dietary supplementation with glucomannan on plasma total cholesterol and low density lipoprotein cholesterol in hypercholesterolemic children. Nutr Metab Cardiovasc Dis . 2005;15(3):174-180.
6 Luo DY. Inhibitory effect of refined Amorphophallus konjac on MNNG-induced lung cancers in mice [in Chinese]. Zhonghua Zhong Liu Za Zhi . 1992;14(1):48-50.
Glucomannan is well tolerated and is generally considered safe.
Glucomannan has been used for centuries in traditional Japanese cooking as a thickener or gelling agent.
Chinese have used glucomannan for more than 2,000 years to treat asthma, cough, hernia, breast pain, burns and skin diseases.
Nowadays, glucomannan is used in foods, drinks and cosmetics because of its gelling properties. It has been approved since 1994 by the Food and Drug Administration (FDA).
Elephant yam is so called because of its huge size and resemblance with the elephant foot.
¹ Chua M, Baldwin TC, Hocking TJ, Chan K. Traditional uses and potential health benefits of Amorphophallus konjac K. Koch ex N.E.Br. J Ethnopharmacol. 2010;128(2):268-278.