The most commonly cultivated species of echinacea (pronounced ek-i-nay-sha) is known botanically as Echinacea purpurea. The application of this herb in medicine is of American origin. Native Americans knew the beautiful purple coneflower as a valuable medicinal herb to “purify the blood.” In the late 1800s the Lloyd brothers of Cincinnati first sold echinacea as an herbal product for treating infections. With the introduction of sulfa drugs in the 1930s and antibiotics in the 1940s, Echinacea fell into disuse, though it has remained popular in Europe and is one of the leading pharmaceutical products in total sales, including the sales of conventional medications. In Germany, echinacea is listed for supportive use in colds and other upper respiratory infections.
Most commercially available echinacea products that have been tested for immune effects are standardized hydroalcoholic extracts of the plant or its juice. These products are, in effect, concentrates of the active principals of the plant. Less is known about the benefit of the whole dried herb.
The root or flowering tops of the plant contain a number of resting compounds that have effects in stimulating the immune system and increasing the activities of the white blood cells that fight invading microorganisms. The water soluble polysaccharides in the plant seem to be important as immune stimulants but other chemicals such as cichoric acid and rutin probably are active also. Like so many of the botanicals, the exact compound or compounds in echinacea responsible for the therapeutic effects are not known.
EVIDENCE OF EFFICACY
Despite all of the interest and the popularity of echinacea as an agent to boost the immune system and to treat and prevent colds and flu, few studies have tested echinacea for these purposes. Most of the studies have examined the ability of extracts of echinacea to enhance indexes of the immune function, and the results indicate that they do. Nevertheless, the critical question of whether immune stimulation improves the body’s ability to resist colds and flu is largely unanswered. One Swiss study tested a proprietary cold preparation with echinacea versus placebo on thirty-two adults. The investigators found that colds were a day shorter and less severe in the echinacea-treated group. Unfortunately, the product being tested also had 100 mg of vitamin C in it, so we cannot say for sure that the treatment success was due to the echinacea. Another study showed that 900 mg of echinacea significantly reduced flu symptoms compared to a placebo and a 450 mg dose of echinacea. A liquid extract of echinacea also was reported to reduce the length and severity of colds and flu over a two-month test period in 108 subjects.
Recent evidence suggests that taking echinacea every day to try and prevent colds or flu is not the best way to use this plant. The body may adapt to prolonged use of an immunostimulant so that it no longer works. A large German study of 300 volunteers found no benefit for use of a liquid extract of two types of echinacea twice a day for three months compared to use of a placebo for prevention of colds and flu. We believe that it is better to take echinacea at the first sign of the cold/flu and during the time symptoms are present. We are convinced that it works for many people when used in this way.
There is some evidence that echinacea treatment may decrease the recurrence rate of vaginal Candida infections and that topical use might be useful for minor skin infections. Extracts of echinacea are also being tested in cancer patients to see if immune stimulation will improve survival times.
DANGERS
Echinacea and extracts of echinacea are considered nontoxic. Allergic reactions are possible, particularly if you are allergic to plants of the daisy family.
Recommendations
The extent to which echinacea might reduce the incidence and length of colds and flu is unknown; more studies are needed. As a whole, the literature points to echinacea’s ability to enhance the immune system. The results from the few trials that have been reported indicate an ability to reduce both the incidence and severity of colds and flu. Taking echinacea in doses of 250 to 500 mg twice a day at the first sign of a cold or flu is worthwhile. Echinacea may have a future role as an adjunct to cancer and AIDS treatment.
Echinacea liquid extract (tincture) is preferred by us because it comes into direct contact with mouth and throat tissues, where local immunity is important in stopping the virus from attaching to tissues. Place the equivalent of 250 to 300 mg of extract of echinacea in a glass of water, swish it around in your mouth, and then swallow the liquid, three times a day. Capsules are readily available and can be opened and the content placed in juice or water and used like the liquid extract form in the mouth and throat. The crude dried herb in capsule form is also available, but the extract is more potent and is preferred. Chronic use is not advised unless recommended and monitored by a qualified health care professional.
