Echinacea: Treatment or
Prevention?
HealthNews from the publishers of the New England
Journal of Medicine
Few ailments are more inconvenient and
ubiquitous than the common cold. No wonder so many consumers are turning to
herbal remedies such as echinacea, with hopes that it will help them stay
healthy or get better quicker. But as the popularity of herbal treatments has grown, so has confusion about how
these remedies are best used.
Only
recently have rigorous medical studies evaluating herbal products been
published. In the August Journal of Family Practice, American researchers
reviewed 13 European trials that tested echinacea for the common cold. Nine of
these trials evaluated echinacea's effectiveness as a treatment for upper
respiratory symptoms. The other four evaluated the herb's ability to prevent
colds.
Of the nine treatment trials,
eight found some benefit to taking echinacea. Patients in the studies had either
less severe symptoms or a shorter duration of illness than people who received a
placebo, especially when they took large doses of the herb early in the course
of the cold. In the four prevention trials, however, echinacea did not appear to
provide much benefit. Patients taking the herb to ward off a cold were just
about as likely to get sick as their counterparts given a dummy
drug.
The study's authors conclude that
echinacea may be useful if taken at the first sign of a cold, but not when used
routinely as a preventive. They recommend using the herb several times a day
early in the illness and then discontinuing it as symptoms
improve.
However, because there is little
research comparing specific formulations, it's still not clear whether one
should use extracts of the roots, leaves, or flowers or which of the three
commonly used echinacea species — Echinacea purpurea, E.
augustifolia or E. pallida — is most likely to be effective. People
with allergies to the daisy family of plants and those with
autoimmune diseases should avoid these products, as should children and pregnant
women, in whom echinacea has not been studied.
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