- PORTLAND, Ore. (AP) -- Echinacea, the top-selling herbal supplement, apparently
has little effect on the common cold, according to a study published Thursday
in the Archives of Family Medicine.
- Echinacea, an extract from the coneflower,
was no better at preventing colds than a placebo, the study said.
- The study is among various research into
the effectiveness of alternative medicine being published this week by
the Journal of the American Medical Association and its sister publications,
including the Archives of Family Medicine.
- Echinacea has gained vast popularity
as the number of Americans using herbal therapies has grown to almost one
in five, according to a national study published this year.
- Echinacea comes in pill or tincture form
and often contains two or more species, even using the root. It may be
mixed with other ingredients such as zinc.
- But scientists are unsure which of the
eight species of plants that provide echinacea might be most effective,
what part of the plant should be used and how high a dosage is needed.
- Research in Germany -- home of most of
the research on echinacea -- suggests it increases the number of white
blood cells and buoys the body's ability to gobble up invading organisms.
- But according to today's study, also
by doctors in Germany, there were no significant differences among the
people given echinacea or a placebo.
- The study of 289 healthy people used
two species, Echinacea angustifolia and Echinacea purpurea. One group of
participants took the angustifolia, one took the purpurea and a third took
- The study's authors emphasized the need
for more research.
- Dr. Bruce Goldberg, an associate professor
of family medicine at Oregon Health Sciences University who is studying
the herb, cautioned against putting too much weight on the study.
- "We have very little information
on which to base any sort of strategy," he said. "We don't know
what dose, what preparation, for how long, whether there might be some
populations of individuals who benefit from this and others who don't."