A new, preliminary study
shows the popular over-the-counter herbal supplement echinacea does
stimulate immune system activity, but the lead researcher warns it should not be
Susan Percival of the University of Florida's Institute of Food and Agricultural Sciences in Gainesville gave 10 healthy, college-age men echinacea supplements for four days. She took blood samples from the men on days 1 and 4 of the study. By day 4, she found the men's white blood cells had three times greater an ability to destroy bacteria.
. Recent research has produced conflicting results on the purple coneflower. Some research has claimed echinacea prevents the common cold by boosting the immune system. Percival disagrees. "I don't think echinacea is supposed to prevent colds," she tells OnHealth. "I don't think we should take it chronically. I think it should be taken at the first signs of illness."
In a statement released by the university Percival says, "A stimulated immune system produces a lot of free radicals, and we know from other research that free radicals are not a good thing. We want the free radicals to kill microorganisms, but we don't want free radicals being produced all the time because they will damage healthy tissues."
Percival says this study will be expanded to include a larger group of men. The study was funded by General Nutrition Center, Inc., which sells herbal supplements.