Echinacea: why does it work in real life but not in trials?
|Echinacea: why does it work in real life but not in trials?||Darrell Miller||02/04/06|
February 04, 2006 09:54 AM
Author: Darrell Miller (firstname.lastname@example.org)
Subject: Echinacea: why does it work in real life but not in trials?
The Wellness Revolution
Why clinical trials must take into account real dosage amounts!
You took it, and it worked. You’re one of legions of people all over the world who have found the little purple coneflower called Echinacea to be wonderfully effective in fighting colds. Echinacea is among the most popular herbal supplements in North America, accounting for 10% of herbal sales in the U.S.
So why are some in the scientific community saying it doesn’t work?
How Controversy Over a Little Flower
It was a July 2005 study done at the University of Edmonton in Canada, published in the pages of the New England Journal of Medicine, that fueled the fire of controversy. On one side, there’s the community of people who take Echinacea to ward off colds and other respiratory tract infections (staying well or getting better quickly tends to make enthusiastic and loyal followers). On the other side is a spate of studies, culminating in the July 2005, giving the thumbs down to the flower’s healing powers.
The much-touted study was a placebo-controlled trial and was double-blinded (neither test group knew what they were taking). Healthy college students were given a dose of a rhinovirus infection, and were then sent to individual dorm rooms to take either an extract of Echinacea or a placebo. The results were disappointing to those of us expecting the scientific community’s “proof” to match ours—based on what our bodies and senses tell us. The study found no statistically significant difference between severity of symptoms or duration of the rhinovirus between the Echinacea and the control group. Why didn’t the study results match those of so many individuals?
What went wrong?
Noted herbalist and author Roy Upton states, [“The studies which found] positive results had dosages which were consistent with herbalist recommendations.”]
The University of Edmonton study didn’t.
Two oft-cited clinical trials in which positive results were found in the use of Echinacea for the common cold, both in vivo and in human volunteers, have been conducted by researchers Vinti Goel.
Tiny Doses, Minuscule Amounts of Active Herb
It is widely agreed among herbalists that the trial—also conducted by the team at the University of Alberta, Canada—published in the New England Journal of Medicine in July 2005 used radically smaller doses than those traditionally taken, doses so small they couldn’t possibly have worked. In the Turner trial, Echinacea extracts were given in doses of 1.5 ml tid, equivalent to 900mg daily, if the conductors of trial had consulted the real-life herbalist, say the natural health care community, they could have run a test that would have, well, tested something. The usual prescription dose for Echinacea taken by mouth ranges from 500 to 1,000 milligrams per day, and is taken three to five times a day, for seven days. This creates a range of 1500 to 5,000 mg per day. Most studies have shown Echinacea to have the greatest effectiveness when one starts taking it immediately upon feeling the early symptoms of coming down with a cold or virus.
Importantly, Echinacea has been proven in many tests, including those by Bauer and Wagner, Foster, and Hobbs, to have a supportive effect upon the immune system. That Echinacea stimulates macrophages and killer cells is proven.
Turner RB et al. New England Journal of Medicine, 2005 jul 28;353(4):341-8.
Upton R et al. Echinacea purpurea root: standards of analysis, Quality control, and therapeutics, American herbal pharmacopoeia, 2004
Goel v et al. Efficacy of standardized Echinacea preparation (echinilin) for the treatment of common cold: a randomized, double-blind, placebo- controlled trial. Journal of Clinical Pharmaceutical Therapy 2004: Feb,29(1):75-83.