Echinacea: Nature's Cold Fighter?En Español (Spanish Version)
Many people who become interested in herbs and natural remedies began with an introduction to echinacea
, an herbal remedy commonly used for treating colds. Does it really work?
is a perennial plant that grows 1-2 feet (0.3-0.6 meters) in height and looks something like a Black-eyed Susan. Grown both commercially and in the wild, its flower, stem, and root are marketed in pill, liquid, or powdered form.
Originally, echinacea was used by many Midwest Native Americans for a variety of medicinal purposes, including the treatment of infections and poisonous snakebites. As early as the 1880s, echinacea came into favor among American medical practitioners. Despite the fact that in 1910 the American Medical Association dismissed echinacea as worthless, it remained popular in the United States until penicillin and other anti-infection drugs were discovered.
In the 1930s, a German doctor, Gerhard Madaus, began researching the medicinal properties of echinacea. He discovered that it contained certain complex sugar molecules, known as
polysaccharides, which he believed might stimulate the immune system. Dr. Madaus also developed a juice form of echinacea that was derived from the plant's flower.
While echinacea has been promoted as a substance that can stimulate the immune system, this action has not been proven. There is no evidence that echinacea strengthens the immune system when taken over the long term.
However, studies do support the use of echinacea as a treatment for colds
. The herb, taken at the first sign of illness, may reduce your symptoms and help you recover faster. It does not seem, though, that daily doses of echinacea will prevent you from getting sick. Echinacea has been studied for other infections, as well, like chronic bronchitis
and ear infections
, but more research needs to be done in these areas.
While it is not clear exactly how echinacea works, some evidence hints that echinacea acts by doing the following:
phagocytosis, the process by which white blood cells and lymphocytes consume (and thus destroy) foreign organisms in the body
- Increasing the rate at which the immune system ejects foreign organisms from the body
- Increasing the number of cells working as part of the immune system
Increasing the production of
interferon, a major component of the body's immune system
Echinacea is taken at the first sign of a cold or flu and continued for 1-2 weeks. The best tested formulations are extracts made from the above-ground parts of the Echinacea purpurea species. Echinacea purpurea root alone may not be effective. Follow label instructions for dosage. The effectiveness of other echinacea species including E. pallida and E. angustifolia has not been established.
Echinacea has not shown significant side effects in studies but mild limited side effects have been noted, including allergic reactions such as rashes and increased asthma
. Other side effects include minor gastrointestinal symptoms, increased urination, and mild allergic reactions. People allergic to plant families such as the daisy or sunflower should use echinacea with caution.
However, if in fact echinacea stimulates the immune system, it could theoretically cause harm in certain conditions. These include the following:
Finally, it has also been suggested that women should avoid taking echinacea while pregnant.
Since echinacea is a natural growing compound, it is covered by the Dietary Supplement Health and Education Act (DSHEA) and is not regulated by the United States Food and Drug Administration (FDA). DSHEA mandates that the label of a dietary supplement must contain enough information about the composition of the product so that consumers can make informed choices. The information must be presented in the FDA-specified format.
The manufacturer is also responsible for making sure that all the dietary ingredients in the supplements are safe. Manufacturers and distributors do not need to register with the FDA or get FDA approval before producing or selling dietary supplements, nor is its use or effectiveness substantiated by the FDA.
Longwood Herbal Task Force
National Center for Complementary and Alternative Medicine
Public Health Agency of Canada
About echinacea. University of Pittsburgh website. Available at: http://www.pitt.edu/~cjm6/w98echin.html . Published November 1998. Accessed October 17, 2013.
Bent S. Herbal medicine in the United States: review of efficacy, safety, and regulation. J Gen Intern Med. 2008 June; 23(6): 854-859.
Dietary supplements. US Food & Drug Administration website. Available at: http://www.fda.gov/food/dietarysupplements/. Updated August 28, 2013. Accessed Octobr 17, 2013.
Echinacea. EBSCO Natural and Alternative Treatments website. Available at: http://www.ebscohost.com/healthLibrary/. Updated August 2013. Accessed October 17, 2013.
Echinacea. National Center for Complementary and Alternative Medicine website. Available at: http://nccam.nih.gov/health/echinacea. Accessed October 17, 2013.
Echinacea. North Carolina Consortium on Natural Medicines website. Available at: http://www.naturalmedicinesofnc.org/Echinacea/Echinacea-history.html. Accessed October 17, 2013.
Echinacea. Edgewood College website. Available at: http://biology.edgewood.edu/pages/outreach/raingarden/raingarden_echinacea.htm. Accessed October 17, 2013.
Echinacea. The Herb Research Foundation website. Available at: http://www.herbs.org/greenpapers/echinacea.html. Accessed October 17, 2013.
History of echinacea. Vanderbilt University Psychology Department website. Available at: http://healthpsych.psy.vanderbilt.edu/HealthPsych/echinacea-history.htm. Accessed October 17, 2013.
Hostettmann K. [History of a plant: the example of Echinacea]. Forsch Komplementarmed Klass Naturheilkd. 203 Apr;10 Suppl 1:9-12.
Parnham MJ. Benefit-risk assessment of the squeezed sap of the purple coneflower ( Echinacea purpurea) for long-term oral immunostimulation. Phytomedicine. 1996;3:95-102.
Timmer A, Günther J, Rücker G, Motschall E, Antes G, Kern WV.
Pelargonium sidoides extract for acute respiratory tract infections.
Cochrane Database Syst Rev. 2008 Jul 16;(3):CD006323.
Last Reviewed October 2013