EchinaceaEchinacea purpurea, E. angustifolia, E. pallida
The decorative plant Echinacea purpurea , or purple coneflower, has been one of the most popular herbal medications in both the United States and Europe for over a century.
Native Americans used the related species Echinacea angustifolia for a wide variety of problems, including respiratory infections and snakebite. Herbal physicians among the European colonists quickly added the herb to their repertoire. Echinacea became tremendously popular toward the end of the nineteenth century, when a businessman named H.C.F. Meyer promoted an herbal concoction containing E. angustifolia . The garish, exaggerated, and poorly written nature of his labeling helped define the characteristics of a "snake oil" remedy.
However, serious manufacturers developed an interest in echinacea as well. By 1920, the respected Lloyd Brothers Pharmaceutical Company of Cincinnati, Ohio, counted echinacea as its largest-selling product. In Europe, physicians took up the American interest in E. angustifolia with enthusiasm. Demand soon outstripped the supply coming from America, and, in an attempt to rapidly plant echinacea locally, the German firm Madeus and Company mistakenly purchased a quantity of Echinacea purpurea seeds. This historical accident is the reason why most echinacea today belongs to the purpurea species instead of angustifolia . Another family member, Echinacea pallida , is also used.
Echinacea was the number one cold and flu remedy in the United States until it was displaced by sulfa antibiotics. Ironically, antibiotics are not effective for colds, while echinacea appears to offer some real help. Echinacea remains the primary remedy for minor respiratory infections in Germany, where over 1.3 million prescriptions are issued each year.
What Is Echinacea Used for Today?
In Europe, and increasingly in the US as well, echinacea products are widely used to treat colds and flus.
The best scientific evidence about echinacea concerns its ability to help you recover from colds and minor flus more quickly. The old saying goes that "a cold lasts 7 days, but if you treat it, it will be over in a week." However, good, if not entirely consistent, evidence tells us that echinacea can actually help you get over colds much faster. 9-19,40
Until recently, it was believed that echinacea acted by stimulating the immune system.
Echinacea has been proposed for the treatment and/or prevention of other acute infections as well. One small double-blind study found that use of an herbal combination containing echinacea enhanced the effectiveness of antibiotic treatment for acute flare-ups of
Finally, echinacea is frequently proposed for
What Is the Scientific Evidence for Echinacea?
Reducing the Symptoms and Duration of Colds
Double-blind, placebo-controlled studies enrolling a total of more than 1,000 individuals have found that various forms and species of echinacea can reduce cold symptoms and help you get over a cold faster. 9-16,45, 56
For example, in one double-blind, placebo-controlled trial, 80 individuals with early cold symptoms were given either an above-ground
extract or placebo.
Another study found evidence that above-ground
can reduce the severity of cold symptoms, but that
root may not be effective. In this double-blind trial, 246 individuals with recent onset of a respiratory infection were given either placebo or one of three
preparations: two formulations of a product made of 95% above-ground herb (leaves, stems, and flowers) and 5% root, and one made only from the roots of the plant.
Symptom reduction with a whole plant formulation of
was seen in a double-blind, placebo-controlled study of 282 people.
However, another double-blind, placebo-controlled study of above-ground
, enrolling 120 people, failed to find benefits as compared to placebo treatment.
In other studies, benefits were seen with a preparation of
A double-blind, placebo-controlled study failed to find benefit with a dry herb product consisting largely of
The bottom line: at present, the best supporting evidence for echinacea involves the above-ground portion or whole plant extract of E. purpurea , but even here the results are less than fully consistent.
"Aborting" a Cold
A double-blind study suggests that echinacea cannot only make colds shorter and less severe, it might also be able to stop a cold that is just starting.
Participants took either echinacea or placebo at a dosage of 20 drops every 2 hours for 1 day, then 20 drops 3 times a day for a total of up to 10 days of treatment. The results were promising. Fewer people in the echinacea group felt that their initial symptoms actually developed into "real" colds (40% of those taking echinacea versus 60% taking the placebo actually became ill). Also, among those who did come down with "real" colds, improvement in the symptoms started sooner in the echinacea group (4 days instead of 8 days). Both of these results were statistically significant.
Several studies have attempted to discover whether the daily use of echinacea can prevent colds from even starting, but the results have not been promising.
In one double-blind, placebo-controlled trial, 302 healthy volunteers were given an alcohol tincture containing either
root, or placebo for 12 weeks.
Another double-blind, placebo-controlled study enrolled 109 individuals with a history of four or more colds during the previous year, and gave them either
juice or placebo for a period of 8 weeks.
Similar results were seen in four other studies as well, enrolling a total of more than 350 individuals.
A study often cited as evidence that echinacea can prevent colds actually found no benefit in the 609 participants taken as a whole.
However, a recent study using a combination product containing echinacea,
Echinacea is usually taken at the first sign of a cold and continued for 7 to 14 days. Longer-term use of echinacea is not recommended. The best (though not entirely consistent) evidence supports the use of products made from the above-ground portions of E. purpurea (specifically, flowers, leaves and stems); E. pallida root has also shown promise, but E. purpurea root appears to be ineffective.
The typical dosage of echinacea powdered extract is 300 mg 3 times a day. Alcohol tincture (1:5) is usually taken at a dosage of 3 to 4 ml 3 times daily, echinacea juice at a dosage of 2 to 3 ml 3 times daily, and whole dried root at 1 to 2 g 3 times daily. There is no broad agreement on what ingredients should be standardized in echinacea tinctures and solid extracts.
Note : A survey of available echinacea products found many problems. 50
Many herbalists feel that liquid forms of echinacea are more effective than tablets or capsules, because they feel that part of echinacea's benefit is due to activation of the tonsils through direct contact.
Echinacea appears to be generally safe. Even when taken in very high doses, it has not been found to cause any toxic effects. 29,51,52,53
Reported side effects are also uncommon and usually limited to minor gastrointestinal symptoms, increased urination, and mild allergic reactions.
Other concerns relate to echinacea’s possible immune-stimulating properties. Immunity is a two-edged sword that the body keeps under careful control; excessively strong immune reactions can be dangerous. Based on this concern, echinacea should be used only with caution (if at all) by individuals with autoimmune disorders, such as multiple sclerosis, lupus, and rheumatoid arthritis.
Furthermore, a recent case report strongly suggests that use of echinacea can trigger episodes of erythema nodosum (EN).
One study raised questions about possible antifertility effects of echinacea.
Animal studies of echinacea are supportive of safety in pregnancy.
Furthermore, studies dating back to the 1950s suggest that echinacea is safe in children.
Two studies suggest that echinacea might interact with various medications by affecting their metabolism in the liver, but the significance of these largely theoretical findings remain unclear.
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Last reviewed April 2009 by EBSCO CAM Review Board
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