Effects of Korean White Ginseng (Panax Ginseng C.A. Meyer) on Vascular and Glycemic Health in Type 2 Diabetes: Results of a Randomized, Double Blind, Placebo-controlled, Multiple-crossover, Acute Dose Escalation Trial

Abstract

Korean red ginseng (steam treated Panax ginseng C.A. Meyer), among most prized traditional herbal remedies, has been clinically shown to improve cardiovascular disease (CVD) risk factors. Whether this holds true for the dried non-steamed variety, known as Korean white ginseng (KWG) is unclear. This study therefore, investigated the efficacy and safety of escalating doses of KWG on vascular and glycemic parameters in type 2 diabetes (T2DM). Using an acute, randomized, placebo-controlled, double-blind, crossover design, 25 participants with well-controlled T2DM (12-males: 13-females, age: 63 ± 9 years, A1c: 6.9 ± 0.7%, BMI: 29.3 ± 4.3 kg/m(2)) underwent five visits during which they received 1 g, 3 g, or 6 g KWG or 3 g wheat-bran control (twice) together with 50 g-glucose load. For the duration of 240 minutes, augmentation index (AI), and central blood pressure were measured at baseline and at 60 min-intervals, and ambulatory blood pressure was assessed at baseline and at 10 min-intervals. Additionally, capillary blood was collected at time zero and at 15, 30, 45, 60, 90, 120, and 180 minutes post-treatment. A symptoms questionnaire was used to assess safety and adverse events. Two-way ANOVA demonstrated a significant time-treatment interaction effect on AI (p = 0.01) with one-way ANOVA showing significant reductions in AI with 3 g KWG relative to control (p = 0.04). Compared to control, acute administration of KWG appeared to be safe, but did not affect any other postprandial, vascular or glycemic parameters. KWG might have a beneficial effect on AI, a cumulative indicator of arterial health. However, these results are preliminary and highlight the need for long-term investigation with a focus on its accountable components.

Clinical trial registration: NCT01699074.

Keywords: Augmentation index; Clinical trial; Korean white ginseng; Postprandial blood glucose; Type 2 diabetes.

Conflict of interest statement

Vladimir Vuksan is a holder of an American (No. 7,326,404 B2) and Canadian (No. 2,410,556) patent for use of viscous fiber blend in diabetes, metabolic syndrome and cholesterol lowering; currently holds grant support for ginseng research from the Canadian Diabetes Association, Canada and the National Institute of Horticultural & Herbal Science, RDA, Korea. Vladimir Vuksan received a travel grant from BTGin Co, Yuseong-gu, Daejeon, Republic of Korea. Vladimir Vuksan and Alexandra L. Jenkins are part owners of Glycemic Index Laboratories, Inc. a contract research organization. For the remaining authors, no conflicts of interested were declared.

Figures

Figure 1

Acute dose effects of KWG treatments on Augmentation Index relative to control. Acute effects of treatment dose 1 g, 3 g, 6 g KWG or control on AI. Values are presented as the mean change from baseline in AI over 4hr post-intervention (n = 25). Control represents the mean response to two placebos. Values are mean ± SEM. KWG, Korean white ginseng; AI, Augmentation index. Two-way ANOVA: Significant time x treatment interaction (p = 0.01). *One-way ANOVA: Significant treatment effect between control and 3 g KWG (p = 0.035); †One-way ANOVA: Significant treatment effect between 3 g KWG and 6 g KWG (p = 0.005); ‡One-way ANOVA: Significant treatment effect between 1 g KWG and 6 g KWG (p = 0.02).

Figure 2A

Acute dose effects of KWG treatments versus control on post-prandial blood glucose incremental area under the curve. Acute effect of treatment dose 1 g, 3 g, 6 g KWG, or control PPBG iAUC (n = 24) after 3hr of intervention. Control represents the mean response to two placebos. Values are mean ± SEM. PPBG: post prandial blood glucose, iAUC: incremental area under the curve, KWG: Korean white ginseng. One-way ANOVA: (p = 0.92)

Figure 2B

Acute dose effects of KWG treatments compared to control on post-prandial blood glucose levels. Acute effects of treatment dose 1 g, 3 g, 6 g KWG, or control on incremental PPBG. Values are presented as the mean change from baseline in PPBG over 3 hr post-intervention (n = 24). Control represents the mean response to two placebos. Values are mean ± SEM. PPBG: post prandial blood glucose, KWG: Korean white ginseng. Two-way ANOVA: (p = 0.29).