Ginseng and Ginsenoside Re Do Not Improve b-Cell Function or Insulin Sensitivity in Overweight and Obese Subjects with Impaired Glucose Tolerance or Diabetes

OBJECTIVE—Ginseng and its active component, ginsenoside Re, are popular herbal products that are advocated for treatment of diabetes. The purpose of this study was to determine whether ginseng or ginsenoside Re improvesb-cell function and insulin sensitivity (IS) in insulin-resistant subjects. RESEARCH DESIGN ANDMETHODS—Overweight or obese subjects (BMI = 34 6 1 kg/m2) with impaired glucose tolerance or newly diagnosed type 2 diabetes were randomized to 30 days of treatment with ginseng root extract (8 g/day), ginsenoside Re (250–500 mg/day), or placebo. b-Cell function was assessed as the disposition index (DI) andmeasured by a frequently sampled oral glucose tolerance test, and IS was assessed as the relative increase in glucose disposal during a hyperinsulinemic-euglycemic clamp procedure plus stable isotope tracer in-fusion. RESULTS—Values for DI and IS after therapy (Post) were not different from values befor