MONDAY, Dec. 20, 2010 (HealthDay News) -- The herbal remedy echinacea, believed by many to cure colds, is no better than a placebo in relieving the symptoms or shortening the duration of illness, a new study finds.
"My advice is, if you are an adult and believe in echinacea, it's safe and you might get some placebo effect if nothing else," said lead researcher Dr. Bruce Barrett, an associate professor of medicine at the University of Wisconsin. "I wouldn't say the results of the trial should dissuade people who are currently using echinacea and feel that it works for them, but there is no new evidence to suggest that we have found the cure for the common cold."
If echinacea was able to significantly reduce the symptoms and length of colds, this study would have found it, Barrett noted. "With this particular dose of this particular formulation of echinacea there was no large benefit," he said.
The report is published in the Dec. 21 issue of the Annals of Internal Medicine.
In the study, Barrett's team randomly assigned 719 people with colds to no treatment, to a pill they knew was echinacea, or to a pill that could either be a placebo or echinacea, but they were not told which. The participants ranged from 12 to 80 years of age.
People in the study, which was funded by the U.S. National Center for Complementary and Alternative Medicine (part of the National Institutes of Health), reported their symptoms twice a day for about a week. Among those receiving echinacea, symptoms subsided seven to 10 hours sooner than those receiving placebo or no treatment. This represented a "small beneficial effect in persons with the common cold," according to the study. However, this slight decrease in the duration of their colds was not statistically significant, Barrett said.
There was also no statistically significant difference in the severity of symptoms between the groups, he added.
Douglas "Duffy" MacKay, vice president for scientific and regulatory affairs at the Council for Responsible Nutrition, a lobbying group for the supplement industry, said that "the cure for the common cold has been an elusive target of the medical community for decades. Unfortunately, the best available treatments for this self-limiting condition are modestly effective."
Although this study did not show that echinacea made much of a difference in fighting colds, the study was limited by its size and method of reporting results, MacKay said. "Had a larger sample size been available, it's quite possible the investigators would have observed statistically significant effects," he said.
While the study did not provide evidence that echinacea is the cure for the common cold, the evidence suggests that echinacea use should be "guided by personal health values," MacKay said.
"Consumers can also be reassured by the strong evidence of safety for echinacea," he said. The totality of evidence suggests that echinacea may shorten the duration of a cold while providing moderate symptomatic relief. This magnitude of benefit is comparable to other choices consumers have when grappling with this common and self-limiting condition."
For more information on colds, visit the U.S. National Library of Medicine.