Glucomannan is a type of fiber that is often used in many Asian health foods. It is also used in many weight loss pills. There is some evidence that glucomannan may be effective for type 2 diabetes, and preliminary studies suggest that it may help with constipation, high cholesterol, and obesity as well. Possible side effects include digestive symptoms (such as bloating and gas).
What Is Glucomannan?Glucomannan is a type of vegetable fiber that comes from the root of a plant known as konjac (Amorphophallus konjac, to be specific). This fiber is commonly used in Asian health foods, and many herbal supplements now contain glucomannan. In addition to its use in foods, the fiber is often used for the following purposes:
- To relieve constipation
- To lower cholesterol
- To aid in weight loss
- To lower blood sugar (in people with type 2 diabetes).
(Click Glucomannan Uses for more information on what it is used for.)
Which Products Contain Glucomannan?Currently there are a large number of products that contain glucomannan. It can be purchased in capsules, tablets, powders, shakes, and a variety of food products (such as konjac noodles or glucomannan flour). Many popular weight loss pills contain it (in combination with other ingredients), including:
- CortiSlim Control™
- Hydroxycut® (ephedra-free formulation)
- Trimspa™ (ephedra-free formulation).
How Does It Work?Glucomannan works like any other fiber product to relieve constipation and lower cholesterol, as well as to help with obesity and type 2 diabetes. It is a fiber that is not absorbed into the body (it stays in the digestive tract). It increases the water absorption into the stool in the colon, helping to relieve constipation. It probably works to lower cholesterol by helping the body get rid of cholesterol through the stool. Because fiber slows the emptying of the stomach, it can help people feel full and can help keep blood sugar more even. This is probably how glucomannan fiber helps with obesity and type 2 diabetes.