FARMINGTON, CONNECTICUT. Despite widespread vaccination, influenza and pneumonia together represent the 4th leading cause of death for older adults. These two diseases are estimated to result in 172,000 hospital admissions and 40,000 deaths every year in the US alone. A group of researchers from 3 American universities now reports that an extract of American ginseng (Panax quinquefolium L.) is highly effective in protecting older nursing home residents from acute respiratory illnesses. The extract, CVT-E002, is manufactured by a Canadian company (C.V. Technologies Inc., Edmonton, Alberta) and has been marketed for several years as an over-the-counter remedy for preventing and treating colds.
The study included 2 randomized, double-blind, placebo-controlled clinical trials conducted during the 2000 and the 2000-2001 influenza seasons. The first trial lasted 8 weeks and involved 89 nursing home residents; the second lasted 12 weeks and involved 109 patients. About 90% of all participants had received the current flu vaccine. Participants were randomized to receive 2 x 200 mg capsules of the ginseng extract or placebo twice daily. They were monitored twice weekly by medical personnel for symptoms of respiratory disease and if symptoms were present, a viral throat or nasopharyngeal culture was performed.
The incidence of diagnosed influenza over the entire trial period was 7% (7 cases/101 subjects) in the
placebo group as compared to 1% (1 case/97 subjects) in the ginseng group. This corresponds to an
impressive relative risk reduction of 86%. Considering both influenza and RSV (respiratory syncytial virus)
resulted in a 9% incidence in the placebo group as compared to 1% in the ginseng group for an equally
impressive 89% relative risk reduction – or, in other words, patients taking the ginseng extract had a 7-fold
decrease in acute respiratory illness. The researchers conclude that CVT-E002 is safe, well-tolerated, and
potentially effective for preventing acute respiratory illnesses such as influenza and RSV. The product is
currently undergoing phase III trials in the USA. NOTE: This study was funded by C.V. Technologies,
Editor's comment: CVT-E002 could be quite a breakthrough as there is no reason to believe that it would, unlike vaccines, be specific to any particular strain of virus. It has been marketed as an effective cold remedy for years and is available in health food stores under the trade name COLD-FX.