Glycemic and lipid responses to glucomannan in Thais with type 2 diabetes mellitus

J Med Assoc Thai. 2007 Oct;90(10):2150-7.


Objective: To evaluate the benefits of glucomannan supplement on glycemic and lipid controls in type 2 diabetic patients.

Material and method: A single-blind, placebo-controlled, crossover trial with two treatments separated by a 2-week washout period was performed in 10 men and 10 women with type 2 diabetes mellitus. Two separated protocols of experiments were sequentially followed. Initially, purified glucomannan (1 g) or placebo was ingested 30 min before 75-g glucose load to evaluate their effects on glucose absorption and insulin secretion in oral glucose tolerance test (OGTT). Later, the glycemic and lipid changes after 4-week intervention with 3 g/day glucomannan comparing to the placebo were determined. The standard OGTT was performed before and after ending of each intervention.

Results: Glucomannan taken before performing the OGTT can lower the rise of blood glucose and insulin from 1 to 2 hour in comparison with the placebo, though a statistically significance of insulin was not achieved. Long-term glucomannan supplement significantly reduced the 120-min glucose area under the curve of OGTT. Glucomannan also decreased the rise of low-density lipoprotein cholesterol (LDL-C). Reductions of HOMA-insulin resistance index and body mass index were detected in glucomannan-treated group though the former was shown only in females. No within- and between-group differences of insulin, fructosamine, and other lipids were observed in glucomannan- nor placebo- treated groups.

Conclusion: In type 2 diabetes, pre-prandial glucomannan ingestion attenuated a rise of blood glucose without significantly affecting insulin levels. Long-term supplement of glucomannan to the regular diabetic regimen lessened post challenge glucose AUC and impeded the rise of LDL-C. Supplement of glucomannan may be beneficial to the glycemic and lipid controls in type 2 diabetes mellitus.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Area Under Curve
  • Blood Glucose / drug effects*
  • Body Mass Index
  • Cathartics / pharmacology*
  • Cholesterol, LDL / drug effects
  • Diabetes Mellitus, Type 2 / physiopathology*
  • Female
  • Glucose Tolerance Test
  • Glycemic Index*
  • Health Status Indicators
  • Humans
  • Insulin Resistance
  • Insulin*
  • Lipids / blood*
  • Male
  • Mannans / pharmacology*
  • Middle Aged
  • Thailand


  • Blood Glucose
  • Cathartics
  • Cholesterol, LDL
  • Insulin
  • Lipids
  • Mannans
  • (1-6)-alpha-glucomannan