Few randomized clinical trials have evaluated the efficacy of ginseng in patients with type 2 diabetes mellitus (T2DM). The current meta-analysis evaluated the ginseng-induced improvement in glucose control and insulin sensitivity in patients with type-2 diabetes or impaired glucose tolerance.
Randomized clinical trials comparing ginseng supplementation versus control, in patients with T2DM or impaired glucose tolerance, were hand-searched from Medline, Cochrane, and Google Scholar databases by 2 independent reviewers using the terms “type 2 diabetes/diabetes/diabetic, impaired glucose tolerance, and ginseng/ginsenoside(s).” The primary outcome analyzed was the change in HbA1c, whereas the secondary outcomes included fasting glucose, postprandial glucose, fasting insulin, postprandial insulin, insulin resistance Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), triglycerides, total cholesterol, low density lipoprotein (LDL), and high density lipoprotein (HDL).
Of the 141 studies identified, 8 studies were chosen for the current meta-analysis. The average number of patients, age, and sex distribution among the groups were comparable. Results reveal no significant difference in HbA1c levels between the ginseng supplementation and the control groups (pooled standardized difference in means = −0.148, 95% CI: −0.637 to 0.228, P = 0.355). Ginseng supplementation improved fasting glucose, postprandial insulin, and HOMA-IR levels, though no difference in postprandial glucose or fasting insulin was observed among the groups. Similarly, triglycerides, total cholesterol, and LDL levels showed significant difference between the treatment groups, while no difference in HDL was seen. In addition, ginseng-related therapy was ineffective in decreasing the fasting glucose levels in patients treated with oral hypoglycemic agents or insulin.
The present results establish the benefit of ginseng supplementation in improving glucose control and insulin sensitivity in patients with T2DM or impaired glucose intolerance.