Echinacea is a perennial plant native to North America that is farmed in both the United States and Europe for use in dietary supplements. Echinacea is a genus in the aster family containing nine plant species. Three species, Echinacea angustifolia, E. purpurea, and E. pallida are used in complementary and alternative medicine in the United States and Europe.
Echinacea has been used as a medicinal herb in North America for more than 400 years. Native Americans used echinacea to treat wounds and snakebites, infections and as a general booster of health. In the 1930s, the herb was very popular in both the United States and Europe, as it was thought to fight infection by boosting the immune system. It was used to treat conditions as diverse as colds, influenza, eczema, many different types of infections, malaria, syphilis, cancer, and diphtheria. As antibiotics became more widely available after World War II, echinacea's popularity declined, only to rise again in the 1980s. It is one of the most frequently used herbal remedies in North America and Europe. Echinacea is especially popular in Germany, where many practitioners of conventional medicine accept it as a safe and effective treatment for cold symptoms. Echinacea is increasingly accepted for this use by conventional medical practitioners in the United States.
Echinacea is a perennial herb with slender, rough leaves arranged opposite each other on a stem that grows to a height of about 18 in (45 cm) and produces a single large purplish flower. Both the above ground parts of the plant and the roots are used in dietary supplements. Fresh leaves are pressed and the resulting juice is used in extracts or tinctures, or it is combined with other ingredients to make a paste that can be applied to the skin. Dried leaves and roots are powered and made into tea or capsules. An injectable form of echinacea is available in Europe, but not in the United States. The active ingredients of echinacea have not been adequately identified. As a result, it is difficult to compare the strength and potency of different forms of the herb or the same formulation made by different manufacturers.
Although echinacea has been used for hundreds of years, only recently have researchers started to examine its effectiveness in large, independent, rigorously controlled studies. Many early studies done in Germany suggested that the herb was effective in treating certain conditions. In the United States, the National Center for Complementary and Alternative Medicine (NCCAM), a government organization within the National Institutes of Health, continues to conduct studies on the safety and effectiveness of echinacea in treating a variety of conditions.
In the United States, the Food and Drug Administration (FDA) regulates dietary supplements such as echinacea using the same laws that regulate food, rather than the laws that regulate prescription and over-the-counter medications. Unlike conventional drugs, dietary supplements are not required to undergo rigorous testing to show that they are safe and effective before they are marketed to the public. One consequence of this is that there are many fewer studies of dietary supplements, and some of those studies are sponsored by the manufacturers who have an economic investment in positive outcomes. Too often, studies of dietary supplements are small, poorly designed, poorly controlled, or incompletely reported, making it is difficult to draw hard conclusions about the effectiveness and safety of the product.
For years, echinacea has been taken to improve general health and to treat a variety of infections because it is thought to boost the immune system. Laboratory analyses of the ingredients in echinacea and some animal studies have suggested that echinacea does stimulate immune system cells in humans. However, there is unclear evidence about whether this provides any health benefits.
Claims have also been made that genital herpes can be successfully treated with echinacea. Although there is some theoretical basis for this, both National Standard and the Natural Medicine Comprehensive Database consider echinacea ineffective when used for genital herpes.
There is not enough high-quality scientific evidence to rate echinacea's effectiveness in treating other health problems including cancer, eye infection, migraine headaches, eczema, allergies, bee stings, attention deficit hyperactivity disorder, and chronic fatigue syndrome.
Despite mixed evidence about the effectiveness of echinacea, the herb generally appears to be safe when taken by adults in moderate amounts for short periods. There is no standardization of the amount of active ingredient in products containing echinacea. Guidelines of normal doses for a 150 lb. (70 kg) adult taken three times a day are:
Lower doses of echinacea for children, based on the weight of the child, are generally thought to be safe. One study of pregnant women using echinacea found that moderate use of the herb during the first three months of pregnancy did not increase the likelihood of the baby being born with major birth defects, however, many physicians warn against taking herbal medicines during pregnancy because they are not as strictly regulated as pharmaceuticals and may contain undeclared ingredients. The safety of echinacea use in breastfeeding women has not been adequately studied.
Individuals interested in taking echinacea should consult their healthcare provider and other reputable sources of information before starting the herb. Pregnant or breastfeeding women should be especially careful to discuss the use of echinacea and all other drugs and supplements with their healthcare provider.
As with any medication, more is not necessarily better, and the word “natural” or “organic” on the label does not mean the product is safe. Overdose can cause serious side effects. In the event of side effects, echinacea should be stopped immediately and the side effects reported to a healthcare professional. People with autoimmune diseases (e.g., AIDS, multiple sclerosis) are often counseled to avoid echinacea, because of theoretical, but unproven, negative effects on the immune system.
Since echinacea may stimulate the immune system, individuals who are taking immune system suppressant drugs following cancer treatment or organ transplant should avoid echinacea.
People who are allergic to ragweed, chrysanthemums, marigolds, daisies, and related plants have a greater chance of being allergic to echinacea. Allergic reactions have been reported on rare occasions to be severe enough to cause breathing difficulties, especially in people with asthma. Much more common are allergic reactions consisting of a rash, sneezing, or runny nose.
Parents should be aware that the safe dose of many herbal supplements has not been established for children. Accidental overdose may occur if children are given adult herbal supplements.
See also AIDS/HIV diet and nutrition .
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American Botanical Council. “Echinacea purpurea, E. Angustifolia/Compositae & E. pallida.” HerbMed.org . http://www.herbmed.org/index.html#param.wapp?sw_page=viewHerb%3FherbID%3D6 (accessed March 27, 2018).
National Center for Complementary and Integratived Health (NCCIH). “Echinacea.” National Institutes of Health. https://nccih.nih.gov/health/echinacea/ataglance.htm (accessed March 27, 2018).
American Botanical Council, 6200 Manor Rd., Austin, TX, (512) 926-4900, Fax: (512) 926-2345, http://abc.herbalgram.org .
National Center for Complementary and Alternative Medicine Clearinghouse, PO Box 7923, Gaithersburg, MD, 20898, (888) 644-6226, Fax: (866) 464-3616, firstname.lastname@example.org, http://nccam.nih.gov .
Office of Dietary Supplements, National Institutes of Health, 6100 Executive Blvd., Rm. 3B01, MSC 7517, Bethesda, MD, 20892-7517, (301) 435-2920, Fax: (301) 480-1845, email@example.com, http://ods.od.nih.gov .
Tish Davidson, AM