American ginseng attenuates postprandial glycemia in a time-dependent but not dose-dependent manner in healthy individuals - Panax quinquefolius L

Alternative Medicine Review, June, 2001 by V Vuksan, JL Sievenpiper, J Wong

American ginseng (Panax quinquefolius L.) attenuates postprandial glycemia in a time-dependent but not dose-dependent manner in healthy individuals. Vuksan V, Sievenpiper JL, Wong J, et al. Am J Clin Nutr 2001;73:753-758.

BACKGROUND: We previously showed that 3 g American ginseng administered 40 minutes before an oral glucose challenge significantly reduces postprandial glycemia in subjects without diabetes. Whether this effect can be replicated with doses [is less than] 3 g and administration times closer to the oral glucose challenge is unclear. OBJECTIVE: Our objective was to study the dosing and timing effects of American ginseng on postprandial glycemia. DESIGN: In a random crossover design, 12 healthy individuals [X /- SEM age: 42 /- 7 y; body mass index (BMI; in kg/m2): 24.1 /- 1.1] received 16 treatments: 0 (placebo), 1, 2, or 3 g American ginseng at 40, 20, 10, or 0 min before a 25-g oral glucose challenge. Capillary blood was collected before administration and at 0, 15, 30, 45, 60, and 90 min after the start of the glucose challenge. RESULTS: Two-way analysis of variance showed that the main effects of treatment and administration time were significant (P [is less than] 0.05). Glycemia was lower over the last 45 min of the test after doses of 1, 2, or 3 g ginseng than after placebo (P [is less than] 0.05); there were no significant differences between doses. The reductions in the areas under the curve for these 3 doses were 14.4 /- 6.5%, 10.6 /- 4.0%, and 9.1 /- 6%, respectively. Glycemia in the last hour of the test and area under the curve were significantly lower when ginseng was administered 40 min before the challenge than when it was administered 20, 10, or 0 min before the challenge (P [is less than] 0.05). CONCLUSIONS: American ginseng reduced postprandial glycemia in subjects without diabetes. These reductions were time dependent but not dose dependent: an effect was seen only when the ginseng was administered 40 min before the challenge. Doses within the range of 1-3 g were equally effective.