What Is the Scientific Evidence for Glucomannan?
In a double-blind study, 63 people were given either 3.9 g per day of glucomannan or placebo for 4 weeks and then switched to the other treatment.20 While taking glucomannan, participants showed significant reductions in total cholesterol, LDL cholesterol, and triglycerides, as compared to placebo. In addition, their systolic blood pressure (the upper number in the blood pressure reading) was also reduced. However, there was no significant increase in HDL cholesterol and no improvement in the ratio of LDL to HDL cholesterol. Participants in another study were given either 3 g per day of glucomannan or placebo over an 8-week period.21 The glucomannan group showed improvements in total and HDL cholesterol as well as a reduction in systolic blood pressure. Those taking glucomannan also lost weight, whereas the placebo group gained weight over the length of the trial. Several other controlled studies have found similar results.22-25,37 And, in a mathematical review combining the results of
