Members of the herbal medicine community are criticizing a clinical study released last week that claimed echinacea was ineffective. 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.
Another problem with the study was the dosage administered, said Silverman. "We believe that with more frequent and higher dosage, the results might have been different," he said, explaining that the dosage used in the study was probably one-third of what it should have been.
Silverman 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 to 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."
Though Silverman took issue with the methods of this latest study, he suggested that retailers and consumers take all research into consideration, both positive and negative, when making decisions about echinacea.
The published discussion of the study itself 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."
Turner said this study should be seen as the latest step in a series of studies that are becoming more definitive as science gets better and weaknesses in 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.