Glucomannan, also called konjac, is a supplemental source of soluble fiber produced from the roots or tubers of the elephant yam plant. It has many uses in Chinese traditional medicine, some of which are supported by preliminary research results. Speak with your doctor before taking glucomannan supplements, however, as they aren't safe for everyone and can interact with certain medications.
Potential Positive Effects
Glucomannan may help lower your triglycerides, total cholesterol and low-density lipoprotein, or "bad" cholesterol, without affecting your levels of high-density lipoprotein, or "good" cholesterol, according to a review article published in the "American Journal of Clinical Nutrition" in October 2008. The authors note that this fiber may also help you lose weight and control your blood sugar levels. Other potential uses require further study, including the use of glucomannan for treating high thyroid hormone levels, constipation and lung cancer, as the evidence for these uses is still preliminary and, in some cases, conflicting.