Members of the herbal medicine community are criticizing a recent clinical study that claims echinacea is ineffective in treating cold symptoms. Industry members also are firing back at media sources they say extrapolated incorrect conclusions from the study.
The study, published in the July 28 issue of the New England Journal of Medicine, concluded that certain extracts of echinacea were statistically ineffective in lowering rates of infection or severity of symptoms of an induced cold virus in a group of 399 college students who had been sequestered in individual hotel rooms for analysis.
Wayne Silverman, chief administrative officer for the American Botanical Council, pointed out three main flaws of the study, while acknowledging that the study had been performed in a scientific manner by a reputable institute.
?First, the extracts used in the study were made in a university lab,? said Silverman, who explained that the extracts were not comparable to any echinacea products currently sold.
Even in the published discussion of the study, researchers said, ?Given the great variety of echinacea preparations, it will be difficult to provide conclusive evidence that echinacea has no role in the treatment of the common cold.?
Another problem with the study was the dosage administered, Silverman said. ?We believe that with more frequent and higher dosage, the results might have been different.? The dosage used in the study was probably one-third of what it should have been, he said.
He also pointed out that using a group of college students in a sequestered environment would not likely produce the same results as using subjects with weaker immune systems, such as the elderly.
Ronald Turner, one of the researchers who contributed to the study, said the rationale for dosage and extract choice was to move discussion away from whether any specific product had effects on a cold virus, rather than whether products with a certain phytochemical profile had effects. Turner said the co-investigator and echinacea expert with whom the researchers consulted was not comfortable using a dosage of more than 900 milligrams per day.
?Unfortunately,? said Silverman, ?the results [of this study] have been extrapolated to mean echinacea is not effective, period. This study should not be used as a reason to think echinacea is not effective at all.?
Don Summerfield, vice president of integrative medicine for Pharmaca Integrative Pharmacy based in Boulder, Colo., raised another objection. He said Pharmaca believes coverage of the study was biased, since media sources positioned such a poorly designed study as front-page news.
?Why does the media ignore running news pieces on the well-designed studies, such as the one published in The Journal of Clinical Pharmacy and Therapeutics?? in 2004, Summerfield asked. ?[It was] a gold-standard, randomized, double-blind, placebo-controlled study on standardized echinacea preparation [Echinilin], a commercially produced echinacea preparation, which clinically proved echinacea significantly reduced the severity and duration of the common cold.?
Silverman suggested that retailers and consumers take all research into consideration, both positive and negative, when making decisions about echinacea.
Turner said this latest research should be seen as the most recent step in a series of studies that are becoming more definitive as science gets better and weaknesses in research designs are identified and corrected.
?We believe that our results, together with the results of other recent, well-designed trials, suggest that the burden of proof should be on those who advocate this treatment,? Turner said.
Last year, sales of echinacea products totaled about $155 million, according to Nutrition Business Journal.
Natural Foods Merchandiser volume XXVI/number 9/p. 15