In the study, which appears in the Dec. 17 issue of the Annals of Internal Medicine, 73 college students received echinacea on the first day they had signs of a cold and for up to nine days longer. There was no difference detected in duration or severity of the cold symptoms in these students compared with students who received only an inactive placebo, Bruce Barrett, assistant professor of family medicine at the University of Wisconsin and principal investigator of the study, told United Press International.
However, it may be too early to say echinacea has no effect on the cold, Barrett said. Previous studies in Europe "have found a benefit," he noted. It is possible different preparations of the herb from what was used in the current study could produce different results, he said. Likewise, if the same study parameters were applied to a different group, such as the elderly, who are more prone to colds than healthy college students, it also could make a difference, he said.
Barrett added because other researchers currently have echinacea studies in progress, it would be prudent to wait for those results before making a final conclusion about the herb. Nevertheless, Barrett said he would not recommend echinacea as a treatment for the common cold at present because it is "certainly not proven to work."
Ronald Turner, a professor of pediatrics at the University of Virginia in Charlottesville, who wrote an accompanying editorial to the study, told UPI the results could turn out differently if the study were repeated.
"There is no standardization" of echinacea and other herbals, so "it's hard to know how much active ingredient you have," he said, adding "nobody knows what echinacea's active ingredients are, and even if we knew, there's still the problem of manufacturers" devising methods to assure their product has the same level of active ingredient in every batch.
The lack of standardization also means consumers buying these products are wasting their money because "any expectation of benefit is based on faith rather than science," Turner said. "It's entirely possible to even buy the same product over and over again, and it actually has different levels of material in it."
Other than lightening your wallet, the echinacea probably will not harm you, he said. "I'm not aware of any major downside of echinacea in the sense that it kills people or anything like that."
Barrett agreed the herb appears to be safe. "I've done a pretty exhaustive review of safety and found no extremely dangerous side effects," he said.
(Reported by Steve Mitchell, UPI Medical Correspondent, in Washington)