Native to Asia, the konjac plant (Amorphophallus konjac) is characterized by its heavy tubers (10 pounds or more in weight) and blotchy, snakeskin-patterned stem. It is most known as a source of glucomannan, a soluble, fermentable, and highly viscous dietary fiber derived from the roots of the plant.
The konjac plant has been used as a source of both food and medicine in traditional Asian practices for more than a thousand years. More recently, glucomannan extracts derived from the konjac plant have been used as a dietary supplement or as a source of mannose, a sugar substitute in food products.
Given the highly viscous nature of glucomannan fiber, it effectively absorbs water in the digestive tract and decreases the absorption of carbohydrates and cholesterol. As such, since the 1980s, Western medicinal practices have valued glucomannan for its potential to reduce cholesterol levels, constipation, blood sugar, and weight. It has also been explored as a component of artificial skin products, and in the treatment of high blood pressure and hyperthyroidism (overactive thyroid), though additional research in these areas is needed.
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