The herbal remedy ingredient echinacea can reduce the risk of getting a common cold by more than half and reduce the duration of colds by 1.4 days, reported The Independent . Researchers “found that echinacea remedies can reduce the time that a person, once infected, is affected by a cold virus,” it said. The newspaper went on to say, however, that the researchers “stopped short of recommending the prescription of echinacea” until further research could be carried out.Echinacea is the name of a group of plants, most of which have pinkish-purple flowers. The root, seeds and other parts are used in herbal remedies.
This systematic review of randomised clinical trials involving echinacea and the common cold was conducted by Craig Coleman and colleagues at the University of Connecticut and was published in the peer reviewed medical journal the Lancet Infectious Diseases .
Mathematical methods were used to combine the results of multiple studies comparing products containing echinacea with control (no echinacea) and the effect they have on the duration of colds and on the number of new colds people get (incidence). Echinacea was given either before onset of a cold, at the first sign of a cold or during an active cold. All studies used different types of echinacea, different doses of echinacea and/or different preparations of product.
The review found that overall, the use of echinacea products, before a cold, just as a cold was starting or for the duration of an active cold reduced the number of cold episodes from 65% in the control group to 45%. People who took echinacea products were ill for an average of 1.4 days less than those who took nothing.
The researchers interpreted the results to mean "that echinacea decreased the odds of developing the common cold by 58%” and reduced “the duration of a cold by 1.4 days”.
We can’t draw definitive conclusions about the effects of echinacea on the common cold due to weaknesses with the evidence looked at in this review:
Overall, more robust research is needed before the effects of echinacea on prevention or treatment of common colds can be understood.