Although other Australian manufacturers have a blemish-free reputation and continue manufacturing, the effect of the recall devastated retailers. Trust in herbal remedies declined to such an extent that sales dropped by thirty per cent.
Stories about the lack of proper product control are certainly not uncommon. In the US, it was found that out of twenty-five echinacea (purple coneflower or Sampson root) products purchased between October and November 2000, six did not have adequate ingredient labelling as required by law. Five of the remaining nineteen samples failed tests because they either did not have the expected levels of a constituent they were supposed to contain, or had no detectable levels of one or more of the constituents.[xii] Plant substitution has also been a problem. It has been estimated that fifty to ninety per cent of echinacea sold in the USA, up until 1991, was actually Missouri snakeroot (an American Indian herb).
The lack of an active ingredient in thirty-eight bottles of Vital brand Vitamin B Complex capsules was potentially far more serious. Many women of childbearing age take foliate supplements to help prevent birth defects of the brain and spinal cord, such as the neural tube defects associated with spina bifida. The label on this product mentioned that supplementation is recommended when the body might be low in nutrients and cited pregnancy as one example. The label also suggested that one capsule containing four hundred micrograms of folic acid was the recommended dose per day. Alas, the capsules labelled as containing four hundred micrograms of folic acid contained only forty micrograms.
Control of the labelling and processing of herbal remedies is difficult because many plants are known by more than one name, often depending on the country or region of origin. Naming problems not only confuse consumers, they can lead to inappropriate substitution by producers, either ignorantly or deliberately, as a cheaper alternative. Unscrupulous producers can also include additives that do not appear on the label. For example, non-herbal substances, such as prescription drugs or toxic metals (mercury) have been found in imports labelled ‘Chinese herbal medicine’, although they were manufactured in other Asian countries. In some cases of imported herbs, unwitting substitution of a similar plant occurs. For example, a tonic labelled ‘ginseng’ may contain Siberian ginseng, which is a related plant (eleuthero) that has quite different active ingredients. A remedy may also be taken because it is known to contain a particular active ingredient, but if the whole herb is used other active ingredients in the plant may have unwanted effects. On the other hand, it may be the combination of ingredients in the whole herb that makes it therapeutic and using one extracted ingredient may not have the same synergetic effect. Some of the complexities surrounding constituents can be illustrated, again using the herb echinacea as an example.
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
