TORONTO, CANADA. An excessive rise in blood glucose level after a meal (postprandial glycemia) is a prominent feature of diabetes and impaired glucose tolerance. Researchers at the University of Toronto now report that taking American ginseng (Panax quinquefolius L.) before a meal markedly reduces postprandial glycemia. Their clinical trial involved 12 healthy individuals who, in a random crossover design, received a placebo or 1, 2 or 3 grams of American ginseng at 40, 20, 10 or 0 minutes before a 25-gram oral glucose challenge. Blood samples were taken before the challenge and at 0, 15, 30, 45, 60 and 90 minutes after the challenge. The researchers conclude that taking 1 to 3 grams of ginseng 40 minutes before the challenge markedly reduced the rise in blood glucose levels. They speculate that as little as 100 mg of ginseng may be as effective as the 1-gram dose and point to earlier research that showed that supplementing for eight weeks with 200 mg/day of ginseng resulted in an improvement in glycemic control. Other research has shown that American ginseng is also highly effective in reducing postprandial glycemia in diabetics.
Vuksan, Vladimir, et al. American ginseng (Panax quinquefolius L.) attenuates postprandial glycemia in a time-dependent but not dose-dependent manner in healthy individuals. American Journal of Clinical Nutrition, Vol. 73, April 2001, pp. 753-58