Herbal medicines

Abstract

Plants have been used for medicinal purposes throughout human history and although it may seem to us that modern life is innately much more stressful than long ago, the struggle for basic survival then must have been at least as worrying as the more ‘sophisticated’ concerns of today. Thus, it seems likely that healers in primitive societies probably had to treat exactly the same range of disorders as those with which we are familiar. Spells and incantations to drive away evil spirits, which some may interpret as early psychotherapy, might have been combined with the use of herbs with psychoactive properties.

Technology came into play at a surprisingly early stage of herbal medicine, in the way in which plant material was processed. Grinding, roasting and distilling were very early techniques, soon to be accompanied by a variety of horticultural and chemical interventions. Such changes have had a profound effect. They have allowed the active principle of the herb to be concentrated, making the medicine more potent and easier to transport. It also becomes easier to take large doses and unwanted side-effects are often more prominent. Moreover, the beneficial synergistic effects of other compounds present in the original plant material may be eliminated by the purification process. Thus, while modern medicines are firmly rooted in herbalism, they have undergone such profound changes that many people are uneasy about their use and are keen to return to the natural product. However, it is important to emphasise that ‘natural’ and ‘traditional’ medicines are not always benign and gentle, and can themselves cause serious side-effects. Unfortunately, the public are poorly safeguarded in this respect because, in most countries, the regulation and registration of herbal medicines are poorly developed and the quality of herbal products sold is generally not guaranteed.

Despite such concerns, interest in herbal medicines is increasing rapidly. One major advantage is their low cost, which is particularly important for poor countries, which often cannot afford the drugs manufactured by the large pharmaceutical companies. There is, therefore, a financial incentive to build on existing knowledge of traditional medicines and to utilise them to the full.

This is further fuelled by changes in industrialised countries. Here, the accelerating pace of medical advance, accompanied by increasing medical sub-specialisation, is an additional driver for the growing interest in herbal medicine, because conventional care frequently fails to deliver the holistic, patient-focused treatment that many people crave. They therefore turn to the past and seek ‘traditional’ medicine, with its emphasis on the ‘whole’ patient and not on the disease or the malfunctioning bodily system in isolation. This attitude is further reinforced because modern drugs may have powerful and unpleasant side-effects, so that the ‘cure’ feels worse than the disease state itself. The desire for a holistic approach is perhaps even more understandable for those suffering from symptoms of mental ill health, which may threaten an individual’s very sense of ‘self’.

Rising above individual concerns, there is an acute awareness of our ignorance of this huge subject, combined with an anxiety that its sources are under threat environmentally. This threat is not only to the as yet unrecorded plants that may have therapeutic properties – it extends to the indigenous peoples whose knowledge has been handed down over centuries. Thus, there is a real fear that the plants and the associated knowledge may be lost before their existence is known or acknowledged. The World Health Organization (WHO) is responding to this growing interest. It issued a strategy paper on traditional medicine in 2002, the objectives of which are in line with the WHO’s overall medicines strategy (World Health Organization, 2002):

• to integrate relevant aspects of traditional medicine within national healthcare systems by framing national policies on traditional medicine and implementing programmes

• to promote the safety, efficacy and quality of traditional medical practices by providing guidance on regulatory and quality assurance standards

• to increase access to, and the affordability of, traditional medicines

• to promote national use of traditional medicines.

Evaluating herbal medicines is difficult and costly. Accurate plant identification is essential and then active ingredients have to be isolated. The latter is made more difficult because the active ingredients may be influenced by the time of plant collection, the area of plant origin and different environmental conditions. A single medicinal plant may have hundreds of natural constituents and establishing which is responsible for which effect can be prohibitively difficult and expensive.

Such problems are made worse by the lack of cooperation and sharing of information among countries in relation to the regulation of herbal products on the market. Progress would be made more swiftly if this situation were remedied, so that practical and cost-effective ways of evaluating herbal medicines could be devised. However, although regulation and registration procedures for herbal products existed in nearly 70 countries in 2000, only 25 had reported to the WHO that they had a national policy on traditional medicine (World Health Organization, 2002).

Medical education

The effective use of herbal medicine depends on having enough adequately trained physicians. Courses in complementary and alternative medicine are now much more generally available and they are also being offered to medical students, although they tend to provide an academic introduction only, rather than teaching specific clinical skills. The proportion of medical schools in the UK that offer such courses rose from 10% to 40% between 1995 and 1997, and in the USA a large number of medical schools now have classes and seminars on these topics.

Given the holistic philosophy that underlies much traditional medical practice, a few additional classes and seminars in specific subjects, such as herbal medicine, seem a barely adequate response to this very complex area of study. In contrast, on the Indian subcontinent there is an ancient and continuing tradition of teaching traditional medicine, with 108 undergraduate institutions in India that award degrees after 4.5 years of training in the Ayurvedic and Unani traditions – and the medicines used in the latter are primarily herbal in origin (Chopra & Prabhakar, 1994). In China, too, there is a fund of knowledge of herbal medicines that could be a resource for the whole world.

Financial implications

Finally, it is important to consider the financial implications of developing herbal medicine and this is well illustrated by the use of St John’s wort (Hypericum perforatum) in Germany, where sales of the extract had a market value of US$66 million in 1996 (Nash, 1997). The world market for herbal medicines based on traditional knowledge is now estimated at US$60 billion (World Health Organization, 2002), so the financial incentives for the big pharmaceutical companies are obvious. However, the needs and rights of often impoverished countries must be protected, so that they are not outwitted in areas such as patent protection. Above all, it is essential that their patients retain access to the benefits of herbal medicines, which are often very much part of their heritage.

All of this is relevant to all herbal medicines, not just those used in mental illness, although the latter are very much a special case. Given the scale of physical illness and deprivation in many of the poor countries of the world, and the inadequate resources to tackle even the most pressing problems of communicable diseases, it is not surprising that the treatment of mental illness is a comparatively low priority there. Indeed, one of the great inequalities of the modern world relates to the consumption of psychoactive drugs in different countries, with overuse in many developed countries and virtually no use in many of the poorer ones (Ghodse, 2002). Although the cost of synthetic psychoactive drugs and the lack of psychiatrists may remain barriers to treatment for the foreseeable future, it is possible that herbal medicines and traditional knowledge could be developed and provide effective treatment at a lower cost, so that they would be more accessible to those who need them most. Safeguarding the necessary resources should be seen as a global priority.