February 24, 2004 – The results of a preliminary study in mice that have been administered echinacea continuously throughout their lives (from puberty to death) challenge the widely held belief that one should not take this plant for more than two consecutive months.
Commission E recommends not taking echinacea for more than eight weeks. This recommendation is not based on clinical trial results, but rather on the opinion of certain experts who believe that by stimulating the immune system for a long time, as would be the case if one took echinacea on a on a continuous basis, it would risk either becoming exhausted or developing a tolerance to this stimulation, which could make it less effective in the event of contamination by a virus.
During a presentation at the colloquium on scientific research on natural health products held in Montreal, Sandra Miller and Mélanie Brousseau from McGill University demonstrated that mice that received echinacea (a non-standardized product manufactured by the firm Santé Naturelle) lived longer than those in the control group, and that their production of NK lymphocytes, the first line of immune defense, was statistically higher than that of the mice in the control group. By the age of eight months, 20% of the mice in the control group had died, representing a normal death rate in these laboratory animals, while all of the mice in the treated group were still alive. At 14 months (age of old age in mice), only 40% of the mice in the control group had survived compared to 70% of those in the group that received echinacea.
Although mice suffer more or less from the same diseases as humans, the researchers admit that these results do not suggest that long-term administration of echinacea is entirely safe in humans. Hence the need, according to them, to continue their studies.
Pierre Lefrançois – PasseportSanté.net