Although now used for reducing the symptoms of colds and flu, echinacea was once used to treat a variety of complaints including wound healing, toothache and painful joints or even given as an antidote to rattlesnake bite. There are nine species of echinacea, but today only three are commonly used (E. pupurea, E. angustifolia and E. pallida). These three species between them contain at least seventy different biochemical compounds.[xiii] Most of the seventy compounds are common to all three but the rest are only present in two of them. Processing and storage temperatures are known to affect some of the chemical components in one of the species (E. pupurea).[xiv] [xv] Thus using the correct processing method and the correct species are particularly important. Nonetheless, research has shown that correctly produced echinacea derivatives are effective in alleviating flu-like symptoms and they continue to be popular as a self-medication although problems of quality can arise. The Consumers Association in Australia reported in their journal, Choice, that, when ten of the most popular echinacea products found in retail outlets in Sydney were tested, the quantity of their known active ingredients varied. The Association questioned whether the level in most of them would have any greater effect than a placebo. Two of the manufacturers concerned pointed out that not all the active ingredients in echinacea were known. So, in their view, whether the amount of echinacea found in their products was effective was an open question.[xvi] In other words, it did not matter!
Existing laws in most developed countries preclude producers of OTC remedies from claiming any therapeutic value. As previously noted the product label cannot suggest that it is useful in treating, diagnosing, curing or preventing any specific disease. The exceptions are the few OTC preparations that have been approved as ‘drugs’, since these have been subject to the same rigorous testing required of prescription drugs. Among these are the stronger pain relievers (such as paracetamol and codeine phosphate) and the cough mixtures that are sold in pharmacies.
The efficacy of all drugs depends on getting the dose right. In excessive doses all remedies are potentially capable of being lethal. Even a substance as apparently innocuous as water can prove fatal if consumed in sufficiently large quantities to dilute the blood. The science of medicines is intimately linked to the science of poisons. If a remedy interferes powerfully with any body system, an excess is likely to cause unwanted side effects as the story of the Travacalm disaster illustrated. Such disasters are not confined to pre-packaged medicines. Throughout the history of medicine, overdosing with prescribed remedies has led to disaster, as we shall see in later chapters.
Despite the popularity of herbal remedies in the US, little research on their efficacy and safety has been undertaken there. Demonstrating efficacy and safety to FDA’s satisfaction can take ten to fifteen years and, according to pharmaceutical companies, it can cost as much as US$500 million. Herbs cannot be patented because they are found in nature and are not considered an invention. American manufacturers are not interested in pursuing this avenue of research without the protection a patent gives. A patent prevents other companies from reaping the benefits of another company’s research. It is obviously uneconomic to spend money on research and development if others can reap the rewards—another reason why herbal products are likely to remain in the dietary supplement category.
The National Center for Complementary and Alternative Medicine (NCCAM) has supported randomized-controlled trials for dietary supplements. The trials cited here were conducted with the same scientific rigor required for new drugs; that is double-blind, placebo-controlled and randomized. In the gingko biloba study participants were 3,069 normal elderly people (aged 75 years or older) with mild cognitive impairment. It was found that one hundred and twenty milligrams twice a day was not effective in lowering the overall incidence rate of dementia or Alzheimer's disease, but this OTC preparation did reduce blood pressure. Another widely used botanical product consists of the fruit extract of saw palmetto (serenoa repens) which is widely advertised on Australian TV by a well-known manufacturer. The ad features a well-known sportsman without claiming he takes the substance. This extract is reputed to reduce urinary symptoms associated with prostate enlargement in older men. In the trial three hundred and sixty-nine men were randomly assigned to take either the saw palmetto extract or a placebo, and the strength of the dose was increased three times during the study. The effects of the herb were the same as those for the placebo. Other trials of slightly different varieties of saw palmetto also found no effect. In another study on the effect of the fish oil, which many people take because it contains omega-3 polyunsaturated acids and is thought to suppress inflammation and modify the immune system, the outcome was more encouraging. Unfortunately, in this trial the participants were laboratory mice – these little creatures are frequently used for preliminary tests. Half the mice were thin and the others obese. The results showed that omega-3 polyunsaturated acids targeted immune cells in both groups of mice and did appear to enhance immunity.
As an article by NCCAM points out, the eighteen percent of American adults use natural products such as herbs and botanicals do so without much evidence to support their use. The complex chemical mixtures that natural products contain can present a real challenge, particularly when some of the chemical components are so similar that even sensitive tests fail to tell them apart. Encouragingly the results of a recent study suggest a new technique which will allow the study of highly complex products more powerfully and efficiently than previously possible. The new technique enabled researchers to distinguish between nearly identical compounds in the milk thistle plant. If this technique can be used on other plants, it may help resolve one of the frequently stated reasons for the lack of herbal research – it is too difficult.
Most research aims at establishing a baseline against which products can be measured. As mentioned previously, commercially available products are not well standardized. Nor has there been a systematic determination of the optimal dose, schedule or the method of administration. In addition, the frequency and extent of drug reactions are usually unknown.[xvii] All these factors must be established before large-scale trials can begin, although some herbalists have claimed that scientists are so completely committed to western medicine they are not really interested in botanical remedies. That, of course, was one of the reasons that NCCAM was set up in the National Institutes of Health.
In Europe, the amount of research on herbal remedies depends on the country and Germany leads the way. If research on plant-based remedies takes place in the US and UK, each active ingredient must be separately investigated, which is another reason why trials are so expensive and time-consuming. But in Germany a plant-based remedy does not have to be evaluated for each known active ingredient that it contains; it can be evaluated as a whole plant. Hence most research on herbal remedies is carried out there. Another reason for a high level of research activity is that part of the cost of herbal remedies (called phytomedicines) is covered by government health insurance, and eighty per cent of doctors regularly prescribe these for their patients. Therefore, German suppliers are required to provide evidence of quality, safety and efficacy. Evidence may include empirical medical findings or personal experience, as well as findings from controlled clinical studies. A monograph is published for each plant. This lays down the safety and efficacy criteria that become the basis of licensing decisions.
Evidence of traditional use is sufficient to allow the sale of an herbal remedy in France, whereas other pharmaceuticals are subject to strict controls. The same applies to over-the-counter herbals in the UK, although the European Union is trying to introduce laws that will be common to all members. Where ancient herbal medicine continues, in such countries as the People’s Republic of China and India, herbal preparations are considered traditional medicine and exempt from the tests required for other drugs.
It is often claimed that ‘traditional use over many centuries’ means the medicine is safe. This is not necessarily true. One compelling reason is that many forms of possible toxicity, such