Glucomannan: Can Nature’s “Skinny Sponge” Soak up the Fat?
Imagine a plant-based product that can absorb more than 200 times its weight in water, forming a thick, glob of gel.
Sound like something out of a science fiction film? Maybe. But this goo could have very real benefits for human health.
Just think: That gel-like substance might very well help lower cholesterol and blood sugar, keep your digestive system running smoothly – and may even help you lose weight.
No, this is no futuristic fiction. In fact, this fantastic remedy is as close as your local supermarket.
A Fantastic Fiber…
Derived from the root of the elephant yam (Amorphophallus konjac) and also known as konjac, glucomannan is a soluble dietary fiber that’s been a staple in Asia for millennia.
Glucomannan has many culinary uses – including as an ingredient in traditional foods such as noodles, tofu, and more recently in heat-stabilized gelled food products. You can also find it added to some foods as an emulsifier and thickener.
But glucomannan has a long history of medicinal use, as well. See, traditional Chinese medicine values this fiber as a detoxification aid and as a treatment for asthma, cough, and skin disorders, although there’s no evidence to support its effectiveness in these areas.
Asian medicine also relies upon glucomannan for its role in digestion. In fact, the product is so renowned in Japan that it is known as “the broomstick of the intestines,” because of its ability to cleanse the gastrointestinal system and promote regularity.
More recently, glucomannan is being touted for other purported benefits: Based on recent research, some experts now recommend the fiber for people with high cholesterol or type 2 diabetes.
And, of course, glucomannan is on Dr. Mehmet Oz’s radar – the TV doctor has called this supplement a powerful appetite suppressant, “nature’s skinny sponge,” and an impressive weight loss remedy.
But is there any truth to these claims?
Keeps You on Schedule…
When it comes to glucomannan, there’s good news. Researchers have shown that this soluble fiber is an effective way to stay regular and treat constipation in both adults and children.
That’s because glucomannan absorbs water in the stomach and intestines, forming a bulky fiber mass that passes through the colon more easily and with less pressure, which helps prevent constipation.
There’s good scientific evidence to support glucomannan’s benefits for constipation. A preliminary trial, as well as several double-blind studies, have found that glucomannan works, typically helping produce a bowel movement within just 12 to 24 hours in constipated people.
For example, one study of 13 people with constipation showed that taking 1 gram of glucomannan three times a day for 10 days helped speed bowel transit time.1
Another study looked at the effects of 3 or 4 daily grams of glucomannan on the digestive health of 60 men and women. Researchers found that both doses of the fiber supplement were more effective at increasing bowel movements than a placebo, with 4 grams of glucomannan being the most effective.2
Glucomannan appears to help kids, too. One 2004 study of 31 chronically constipated children found that those who took glucomannan had more regular bowel movements and less abdominal pain than those who took a placebo.3
But glucomannan doesn’t just benefit your digestive system.
A Real Multi-tasker….
There’s intriguing evidence that this fiber supplement may help lower cholesterol and blood sugar, too.
See, just as glucomannan absorbs water in the digestive tract, it also absorbs glucose (sugar) and cholesterol, speeding their elimination from the body. So it only makes sense that glucomannan would have beneficial effects on blood sugar and cholesterol levels.
More specifically, glucomannan has been shown to reduce low-density lipoprotein (LDL) cholesterol and triglycerides. Indeed, one 2008 review of 14 clinical trials found that glucomannan may lower cholesterol and triglycerides.4
And a study of 63 healthy men found that those who supplemented with nearly 4 grams of glucomannan daily for 4 weeks saw their levels of LDL cholesterol lower by 7.2 percent and triglycerides by 26 percent.5
Several studies also suggest that glucomannan may improve insulin resistance in people at high risk for type 2 diabetes. One double-blind trial showed that 8 to 13 grams of glucomannan a day significantly improved measures of both blood glucose control and cholesterol in people with insulin resistance.6
But what about those impressive weight loss claims?
Well, more research is needed before we can truly call it a powerful weight loss supplement – but it certainly shows promise.
For instance, researchers gave 20 obese people either 1 gram of glucomannan three times a day before meals, or a placebo. After 8 weeks, they found that the people who took glucomannan lost an average of 5.5 pounds.7
Help It Go Down Easy…
Glucomannan is nontoxic and generally safe, but you should still take a few precautions before deciding to take it.
First, because this fiber can speed stool transit, it can also interfere with the body’s absorption of many drugs, herbs, and supplements. To ensure that you’re getting the full effects of your other medications, be sure to take them 2 hours before or after taking glucomannin.
If you want to take glucomannan to lower cholesterol or blood sugar, talk to your doctor first if you’re already taking other medications, since using it with drugs that treat high cholesterol or diabetes can be problematic.
Glucomannan comes in several different forms, including powders, capsules, and tablets. You can try any that suit you, but make sure to drink enough water when you take glucomannan. There have been cases where the fiber swelled and created a blockage in the esophagus, so you’ll want to make sure you take it with at least a full 8-ounce glass of water.
The recommended dose of glucomannan is 3 to 4 grams a day as a laxative, and up to 13 grams a day to lower cholesterol or blood sugar. Usually it is taken in divided doses before meals.
Since this product can trigger bloating, gas, and diarrhea in some people – especially those not accustomed to a high-fiber diet – you may want to start with lower doses and work your way up over time.
Follow these steps, and see how this “skinny sponge” works for you.
And remember, keep an open mind to new ideas, but ALWAYS do your own homework… and combine that with common sense to figure out what’s best for YOU.
1Marzio 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.
2Marsicano LJ, Berrizbeitia ML, Mondelo A. Use of glucomannan dietary fiber in changes in intestinal habit. G E N 1995;49:7–14.
3Loening-Baucke V, Miele E, Staiano A. Fiber (glucomannan) is beneficial in the treatment of childhood constipation. Pediatrics. 2004 Mar;113(3 Pt 1):e259-64.
4Sood N, Baker W L, Coleman C I. Effect of glucomannan on plasma lipid and glucose concentrations, body weight, and blood pressure: systematic review and meta-analysis. American Journal of Clinical Nutrition 2008; 88(4): 1167-1175.
5Arvill 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.
7Walsh DE, Yaghoubian V, Behforooz A. Effect of glucomannan on obese patients: a clinical study. Int J Obes 1984;8:289–93.
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