It is one of the largest studies yet to question the benefits of the popular
but unproven herbal remedy.
With reported sales of more than $300 million annually, echinacea is one of
the most widely used herbal remedies nationwide. Also known as the purple
coneflower, echinacea is sold in a variety of over-the-counter preparations,
including pills, drops and lozenges that are purported to boost the body's
disease-fighting immune system.
Anecdotal reports and some animal studies suggest the herb can prevent and
relieve respiratory infections, but human studies have had mixed results. The
herb was not effective at treating colds in a small study of college students
published last year.
In the current study of 407 Seattle-area children ages 2 to 11, echinacea
plant extract worked no better than a dummy preparation in reducing sneezing,
runny noses and fever.
"We did not find any group of children in whom echinacea appeared to have a
positive benefit," said the researchers, led by Dr. James Taylor of the
University of Washington's Child Health Institute.
Symptoms lasted an average of nine days in children given echinacea and in
those taking the placebo, and the overall severity of symptoms were similar.
Mild skin rashes occurred in 7 percent of colds treated with echinacea but in
only 2.7 percent of colds treated with the dummy preparation. None of the rashes
required medical treatment.
The findings appear in Wednesday's Journal of the American Medical
Association.
Healthy patients were enrolled and followed for four months. At the outset,
parents were instructed to call the researchers when their children developed at
least two cold symptoms. Parents then were asked to start administering
treatment.
That lag time may explain why no benefits were found, said Mark Blumenthal,
executive director of the American Botanical Council, an independent group that
studies herbs. He said echinacea is thought to work best if taken as soon as the
first symptoms appear.
Some of the children had multiple colds during the study, but there were 33
fewer colds in the echinacea group — results Blumenthal said suggest that
echinacea might have helped prevent subsequent colds.
Taylor called those results could be just a fluke. The study was not designed
to examine prevention.
Blumenthal said the rashes that developed may have been a rare side effect
from pollen in the echinacea plant flower. The echinacea used in the study was
made by the German company Madaus AG and contained extract mostly from the
flower. Blumenthal said many echinacea products are made instead from the root.
Jim Bruce, president of Madaus' United States-based subsidiary, said numerous
previous studies showed the product to be effective at preventing and treating
colds.
