University of Virginia Health System

July 28, 2005
For Immediate Release
Contact: Abena Foreman-Trice
(434) 243-2734

Herbal Cold Remedy used by Millions not Effective, Say UVa Researchers

In one of the largest, multi-center clinical trials to study the effectiveness of the popular herbal cold supplement, Echinacea, researchers at the University of Virginia Health System have found that it has no effect on treating the common cold.

Dr. Ronald Turner, professor of infectious diseases in the pediatrics department at UVa and the lead researcher, found that extracts from Echinacea angustifolia roots did little to help those with rhinovirus or resulting illnesses. The findings appear in the July 28 edition of the New England Journal of Medicine. The study can be found on the web at: http://content.nejm.org/. Echinacea is widely promoted by advocates as a natural cold treatment.

“In our opinion, Echinacea is useless to treat the common cold,” Turner said. "This study adds to the accumulating evidence that suggests that the burden of proof on the herb’s effectiveness should lie with those who advocate this treatment.”

Turner and colleagues tested the efficacy of Echinacea on 399 volunteers between 2002 and 2004. The volunteers tested were recruited from UVa and were all susceptible to an experimental cold virus, rhinovirus type 39. They were divided into seven different groups and exposed to the cold virus through the nose.

Each group then received either a placebo or one of three possible Echinacea treatments (extracts of the herb originally used by Native Americans and endorsed by the World Health Organization for cold treatment). Volunteers were ‘blinded’ and did not know what treatment they were given. After five days of being studied in an isolated setting, there were no significant effects with Echinacea on the rates of infection or the severity of cold symptoms seen among the study participants. About ninety percent of all participants were infected with the cold virus.

“The results of this study demonstrate that, as tested, the putative active constituents of E. angustifolia do not have clinically significant effects on rhinovirus infection or illness,” Turner wrote in the study.  Researchers from Karl-Franzens-Universitaet in Graz, Austria; the Medical University of South Carolina and Clemson University collaborated on the research.

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