Biology 202
2001 Third Web Report
On Serendip

Presently there is a general trend to treat mild illnesses naturally and to avoid strong allopathic medications. People are embracing herbal remedies which are less expensive, readily available, and have many less side effects. Echinacea, considered to have a remarkable immunostimulating activity, is one of the most widely used phytomedicinals for treatment of the common cold, flu, and other upper respiratory tract infections (1). It is readily available in liquid form, capsules, and in tea. You can purchase it over the counter at the drugstore, supermarket, and even at Kmart. I, like many others, have tried echinacea to treat the common cold and flu, but it never seemed to make me feel better. Am I the exception to benefiting from this common herbal remedy, or has the American public at large been conned into believing this plant will prevent them from getting sick?

As of yet, there is no known medication proven to cure the common cold or flu. Both are upper respiratory tract infections caused by viruses and thus treatment in the form of antibiotics will not work. Medications referred by doctors, such as antihistamines, cough suppressants, and decongestants, treat the symptoms of the illness but not the underlying cause. Although echinacea is similar to other treatments in that it does not attempt to cure the illness, it distinguishes itself by directly stimulating the immune system. This novel approach for combating the cold or flu seems to work as well as the more common medical treatments (2).

The herbal remedy echinacea is a family of nine flowering plants belonging to the Asteraceae (Sunflower) family and indigenous to North America. Three species, E. purpurea, E. angustifolia, and E. pallida, are used in medicinal supplements. Liquid extracts of the leaves and above ground parts of E. purpurea and E. angustifolia are the products most commonly available in the United States, while E. pallida is encountered in Europe (2). The study of how herbs affect the immune system is a current hot topic in pharmacological research. Do herbs, like the echinacea plant, really strengthen our resistance and help us lead healthier lives? There appears to be a contradiction between the wisdom of centuries of observation and the scrutiny of scientific laboratory research.

Echinacea was among the most popular herbs used by Native American Indians. Its popularity in treating colds, coughs, and infections continued and in the late nineteenth century echinacea became the best selling medicinal tincture in America (1). However, in 1910 it was dismissed as worthless and ineffective by the American Medical Association, and gradually fell into disuse in this country in the 1930s (4). Europeans, nonetheless, began growing and using echinacea, and to this day have provided the greatest scientific documentation of its value. The extract's popularity in the United States has grown rapidly throughout the 1980s, and the plant is once again among America's best-selling herbal extracts.

Can echinacea effectively shorten the duration of the common cold? Perhaps. The research record on echinacea for the treatment of colds and the flu paints a confusing picture. The most recent studies do little to clear the record, but present a mostly positive outcome. In essence, the most compelling conclusion to be drawn from these studies is that echinacea works most effectively when taken at the first sign of a cold or flu rather than when used as a daily preventative.

Five echinacea clinical trials in the United States have been published since 1997; two showed that echinacea lacked efficacy for treating and preventing the common cold and flu, and the three other trials concluded that it was effective in reducing the frequency, duration, and severity of common cold symptoms (3). These mixed results do little to support echinacea use.

A 1998 Swedish study of people especially susceptible to colds found that E. purpurea "is a safe and effective therapy when taken at the first signs of a common cold" (5). Patients with initial cold symptoms were given an echinacea supplement for ten days. According to patient evaluations, only 40% of those taking echinacea reported to have developed "real" colds as compared to 60% of those in the placebo group. Moreover, for those receiving echinacea who still experienced significant symptoms, they recovered twice as fast as those in the placebo group (four days versus eight days).

Presently, there in no conclusive evidence regarding the effectiveness of echinacea. Many research trials have been performed but they cannot be deemed valid because they were not designed to withstand scientific scrutiny. The best types of trials to determine the effectiveness of echinacea are randomized, double blind, placebo-controlled clinical studies.

A major problem encountered in the recent trials was whether the participants really had a cold, the flu, or some other illness. If some had allergies which echinacea cannot fight, that would explain why the remedy did not work. In addition, echinacea has a distinctive taste. If the placebos did not taste exactly the same as the true herb, people's reports of symptoms may have been influenced by what they thought they were getting.

The three known strains of echinacea used in herbal remedies have varying levels of efficacy and are hard to distinguish. There is significant room for possible misidentification of the species. Also, the lack of a standardized dose and form contributes even greater to the overall ambiguity of the research trials. Scientists need to make certain that they are testing a pure echinacea product of high quality. Unfortunately, not all echinacea preparations contain an appropriate amount of the herb needed to treat the conditions for which they were designed (3).

In addition, many American researchers are not familiar with herbs. They wrongly assume that echinacea supplements, like standardized drugs to treat the cold and flu, have the same potent effects as synthetic chemicals. In contrast, echinacea is a diluted drug preparation (6). It has mild effects and mild side effects. Drastic results cannot be expected to occur overnight with echinacea use. In addition, echinacea should not be evaluated for its effectiveness in treating acute infections, as that is not the purpose of this herbal supplement.

On the other hand, current research has consistently proven that echinacea does cause an increase in the number of immune cells, further enhancing the overall activity of the immune system. Echinacea acts as an overall immunostimulant and is not specific to a particular disease or antigen. Rather, it increases resistance by mobilizing "effector cells" which act against all foreign particles (5). At present, the mechanism for this is not known, nor has the active agent responsible for this immunostimulating activity been found. It would seem to follow from this data that increasing the action of the immune system would better ward off invading bacteria. Moreover, if one has already come down with the common cold or flu, increasing the number of immune cells should destroy the invading bacteria faster. However, there is no current data to support either conjecture.

There seems to be a general lack of rigorous scientific research on natural remedies. Many scientists, in their search for new drugs to combat illness, have looked primarily at chemicals that kill bacteria or other viruses. Perhaps a better idea would be to look for novel ways to boost the immune system, which can then fight against infectious diseases naturally, without the drawbacks of mainstream medications. Though immunostimulants like echinacea cannot replace standard drugs, they may prove superior in some cases to combat infection as they generate strong immune responses.

Unfortunately, many individuals approach echinacea use with unrealistically high expectations. Some expect that after using echinacea once, they will never come down with the common cold or flu again. Echinacea does seem to be relatively effective in reducing the duration and severity of symptoms of the common cold and flu when taken at the first signs of illness. However, there is a lack of research data showing the usefulness of taking echinacea to prevent these symptoms from occurring. Hence, echinacea should not be used as a daily preventive.

There appears to be no harm in taking echinacea to lessen cold or flu symptoms, as it has an excellent safety record. No toxicity or side-effects have been reported with echinacea use. However, there have been a small number of cases in which overly sensitive individuals develop rare allergic reactions to echinacea when using this product for long periods of time. I strongly discourage echinacea use for those suffering from autoimmune diseases, such as lupus, multiple sclerosis, and rheumatoid arthritis. In these cases, the immune system is already overactive, and stimulating the immune system even more may have deleterious effects.

In addition, the effectiveness of echinacea in reducing symptoms is only noted with certain preparations of echinacea. There is not yet enough evidence to recommend a specific over the counter echinacea product, or specific echinacea preparations, for the treatment of the common cold or flu. Unfortunately, the quality of echinacea products varies dramatically from brand to brand. Some supplements have been found that do not even contain enough of the active echinacea ingredients to treat cold or flu symptoms (4). Hence, from the standpoint of the American scientist, more rigorous research is needed to determine whether echinacea really wards off illness and lessens the associated symptoms.

However, we need to be aware that echinacea has been deemed an effective alternative therapy historically and in Europe. This is due to their openness in taking into account many variables when analyzing natural remedies. Europeans recognize the innate differences between herbal therapies and allopathic medications, and do not hold the natural remedies to the same standards required for drug medications. Natural medicines arising from botanical products behave much differently from mainstream medical treatments.

The dichotomy in these findings in comparison to those of Western medicine demonstrates the strictly controlled and very precise scientific thought processes of the American scientist. They tend to dismiss foreign research as invalid and not on par with the quality of research conducted in the United States. Perhaps we need to change the way we study natural remedies and not always put them under the same scrutiny and strict controls as we do with mainstream medical treatments. With this change in Western medicine's approach to natural healing, we may be able to reach conclusions similar to those of the early Americans and Europeans. Individuals, understanding the differences between common drug treatments and herbal medications, may then make the decision for themselves of whether to give echinacea a try.

WWW Sources

2) Center for Science in the Public Interest, Echinacea: Still Out in the Cold?

3) National Center for Biotechnology Information, Current research studies on the effectiveness of echinacea

4) Physicians Research Laboratories, General overview of echinacea use as a herbal remedy

5)Herb Research Foundation 6)Bastyr University Research Institute, Current research projects evaluating echinacea

7)Healthcare Reality Check, Common questions regarding echinacea use answered by Ellen Coleman, RD, MA, MPH

8)American Herbalists Guild, Information regarding the study of herbal medicine

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