We are often asked about the long term use of Echinacea because of the myth that this herb should not be used for more than 4 to 6 weeks.
There is no reliable or conclusive evidence that it is detrimental to use Echinacea for long periods.(1) This was the opinion of Assoc. Professor Kerry Bone, who has made a lifelong study of the plant. When I last checked he had been taking it for well over 5 years. Long term studies are hard to do on humans but on mice it is much easier.
Another researcher who has published some very useful papers is Dr Sandra Miller. Her study of long term use of Echinacea on mice showed significant benefit.
Here’s a quote from her paper:
“Given that the key immune cells acting as the first line of defence against developing neoplasms in mice and humans are NK cells, it is not difficult to conclude that sustained enhancement of NK cells alone, throughout life, could readily account for the reduced frequency in deaths with advancing age. Spontaneous neoplasms, clinically undetectable, are well known to increase with advancing age in humans and mice. Thus, the logical corollary from this study indicates that chronic daily intake of Echinacea, is clearly not detrimental to the immune system, but rather prophylactic.”(2)
The myth arose through the misinterpretation of a German study which injected Echinacea juice over 5 days.(3) While Echinacea was given, phagocytic (immune system) activity remained higher than controls. Only when the Echinacea was stopped did phagocytic activity decline to normal (pretest) values, demonstrating a typical wash-out effect. The study in fact demonstrated that there is a residual stimulating effect which lasted after Echinacea was stopped.
The myth arose through the misinterpretation of a German study which injected Echinacea juice over 5 days.(3) While Echinacea was given, phagocytic (immune system) activity remained higher than controls. Only when the Echinacea was stopped did phagocytic activity decline to normal (pretest) values, demonstrating a typical wash-out effect. The study in fact demonstrated that there is a residual stimulating effect which lasted after Echinacea was stopped.
There is an even better study in horses. It was carried out in Canada on behalf of Bioniche Animal Health manufacturer of the Echinacea product Echi-Fend.
As you see from the graph below the lymphocyte count was still rising after 42 days thoroughly putting paid to the myth that the effect on the immune system runs out of steam after 2 weeks.
So, if you think your horse (or you) needs Echinacea long term use as you think appropriate. Of course if you have any doubts about your horse’s health seek professional advice.
There is more information on Echinacea at equineherbals.com
http://www.equineherbals.com/articles/Echinacea%20under%20the%20Spotlight.html 1 Bone K; Echinacea: When Should it be Used? Modern Phytotherapist Vol 3 No. 3 pp 16-20 (1997)
2 Miller S; Echinacea: A Miracle Herb against Aging and Cancer? Evidence In vivo in Mice. eCAM 2005;2(3)309–314
3 Jurcic, K et al: Zeitschrift fur Phytotherapie 10, 67 (1989)
