07.01.10
Echinacea may help prevent colds and cold-symptoms, but choosing a supplement is difficult due to the range of ingredients offered. To provide consumers guidance, ConsumerLab.com selected and tested a variety of echinacea supplements for adults and children. It found none of the products contaminated with heavy metals, pesticides, or microbes that can occur in some herbs. However, four products lacked sufficient information for consumers to know the amount of echinacea they contain. ConsumerLab.com categorized the remaining products by the type of echinacea listed, commenting on the amount of clinical support for such preparations.
Echinacea is among the top selling herbal supplements, with sales up 7% in 2009 to $132 million, according to Nutrition Business Journal. While there are three species of echinacea used medicinally, Echinacea purpurea is the most commonly used in clinical trials, with preparations typically consisting of extracts of the above-ground portions (stem, leaf, and flower) of the plant. Root preparations with E. angustifolia and E. pallida have also been used with some limited success. However, the chemical constituents responsible for echinacea’s effects have not been well established.
ConsumerLab.com found enormous variation in ingredients among products reviewed, and listed daily amounts of echinacea ranged from just 25 mg to over 1,600 mg for extracts and to as much as 3,600 mg for dried herb powders.
According to Mark Blumenthal, founder and executive director of the American Botanical Council, “Of all of the popular herbs in the U.S. market, the clinical research on echinacea is probably the most challenging to interpret due to the range of preparations used, yielding positive as well as negative results. However, the research does support the use of certain echinacea preparations for either prevention or treatment of upper respiratory symptoms associated with colds and flus.”
Dr. William Obermeyer, ConsumerLab.com’s vice president for research and a former FDA scientist, commented that, “More clinical trials with better chemically characterized echinacea will help improve our understanding of what echinacea does and our ability to identify quality products.”