Konjac-mannan (glucomannan) improves glycemia and other associated risk factors for coronary heart disease in type 2 diabetes. A randomized controlled metabolic trial

Diabetes Care. 1999 Jun;22(6):913-9. doi: 10.2337/diacare.22.6.913.


Objective: To examine whether Konjac-mannan (KJM) fiber improves metabolic control as measured by glycemia, lipidemia, and blood pressure in high-risk type 2 diabetic patients.

Research design and methods: A total of 11 hyperlipidemic and hypertensive type 2 diabetic patients treated conventionally by a low-fat diet and drug therapy participated. After an 8-week baseline, all were randomly assigned to take either KJM fiber-enriched test biscuits (0.7 g/412 kJ [100 kcal] of glucomannan) or matched placebo wheat bran fiber biscuits during two 3-week treatment phases separated by a 2-week washout period. The diet in either case was metabolically controlled and conformed to National Cholesterol Education Program Step 2 guidelines, while medications were maintained constant. Efficacy measures included serum fructosamine, lipid profiles, apolipoproteins, blood pressure, body weight, and nutritional analysis.

Results: Compared with placebo, KJM significantly reduced the metabolic control primary end points: serum fructosamine (5.7%, P = 0.007, adjusted alpha = 0.0167), total:HDL cholesterol ratio (10%, P = 0.03, adjusted alpha = 0.05), and systolic blood pressure (sBP) (6.9%, P = 0.02, adjusted alpha = 0.025). Secondary end points, including body weight, total, LDL, and HDL cholesterol, triglycerides, apolipoproteins A-1, B, and their ratio, glucose, insulin, and diastolic blood pressure, were not significant after adjustment by the Bonferroni-Hochberg procedure.

Conclusions: KJM fiber added to conventional treatment may ameliorate glycemic control, blood lipid profile, and sBP in high-risk diabetic individuals, possibly improving the effectiveness of conventional treatment in type 2 diabetes.

Publication types

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

MeSH terms

  • Apolipoproteins / blood
  • Blood Glucose / metabolism*
  • Blood Pressure
  • Body Weight
  • Cholesterol / blood*
  • Coronary Disease / epidemiology
  • Coronary Disease / prevention & control*
  • Diabetes Mellitus / blood
  • Diabetes Mellitus / physiopathology
  • Diabetes Mellitus / therapy
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / physiopathology
  • Diabetes Mellitus, Type 2 / therapy*
  • Diet, Diabetic*
  • Dietary Fiber / therapeutic use*
  • Female
  • Fructosamine / blood*
  • Humans
  • Insulin / blood
  • Male
  • Mannans / therapeutic use*
  • Middle Aged
  • Obesity
  • Risk Factors
  • Triglycerides / blood


  • Apolipoproteins
  • Blood Glucose
  • Dietary Fiber
  • Insulin
  • Mannans
  • Triglycerides
  • (1-6)-alpha-glucomannan
  • Fructosamine
  • Cholesterol