Ginseng is a green, perennial herb that is mainly grown for its root. Although there are many so-called ginsengs on the market today, in botanical terms, there are only two authentic types: North American ginseng (panax quinquefolius) and Asian ginseng (Panax ginseng).
North American and Asian ginseng differ in their chemical composition and each appears to have distinct biological properties. While Asian ginseng has been studied for many years, it has only been in the last 20 years that Western researchers have turned their attention to the medicinal properties of North American ginseng. Although research is in its early stages, evidence supporting the use of Ontario grown ginseng in the treatment of a variety of conditions is beginning to emerge.
One trial evaluated Ontario-grown ginseng in the prevention of acute respiratory illness in 128 elderly adults within an institutional setting. After 8-12 weeks of treatment with North American ginseng extract, the seniors experienced an 89% reduction in the risk of developing cold or flu. Most of these seniors had received vaccinations (90%) and the ginseng extract appeared to be safe and complementary.
McElhaney JE, Gravenstein S, Cole SK, et al. A placebo-controlled trial of a proprietary extract of North American ginseng (CVT-E002) to prevent acute respiratory illness in institutionalized older adults. J Am Geriatr Soc 2004 Jan;52(1) : 13-9.