Complementary/alternative medicine (CAM) can be bewildering. All the indicators suggest it is booming. Sales figures for herbal, homeopathic and other natural medicines are climbing steadily, and Brits are spending £1.6bn on CAM every year. Yet in recent months CAM has found itself increasingly the target of criticism in what appears to be a wave of new realism.
In the past week both herbalism and homeopathy have came under considerable fire from the scientific establishment. In Paris, the prestigious Académie de Médecine, an advisory body of distinguished physicians, claimed that homoeopathy was without scientific foundation.
"Homeopathy is a method dreamed up two centuries ago, based on prejudices that were devoid of any foundation," said the report. "It has survived as a doctrine completely outside the remarkable scientific movement which has been transforming medicine for two centuries."
A day earlier, the British Association's Festival of Science was told that herbal remedies were putting "thousands at risk". Professor Peter Houghton of King's College London told the conference: "Are herbal medicines safe? The short answer is no. A lot of herbal medicines have not been subjected to any clinical trials and there is much material marketed of unknown quality."
In July, in an open letter to the British Medical Journal, the eminent cancer expert Professor Michael Baum challenged Prince Charles's romance with a controversial alternative cancer treatment, called the Gerson therapy treatment - which advises lots of fruit juice, combined with coffee enemas, as an alternative to conventional cancer treatments. In addition, the Medicines and Healthcare Products Regulatory agency (MHRA) recently issued a caution concerning traditional Chinese medicines, warning that there could be no guarantees of the safety or quality of such remedies.
Are we seeing the beginning of a backlash against alternative medicines and therapies? It remains to be seen, but perhaps it is time to take stock and determine where all this might be heading.
Both in terms of CAM use and research, Britain is doing very well. About a quarter of us try CAM, and most GPs now recommend some kind of complementary therapy to their patients, at least occasionally. The government's current emphasis on patient choice, however, hardly cuts the mustard in CAM. As they understand it, the choice is between treatments that have been proven to work. So CAM is usually left behind and our choice is confined to the option of paying for CAM out of our own pockets. The NHS still contributes negligible amounts.
The volume of Britain's CAM research has grown remarkably - only our colleagues in the US are currently more active. What is vexing, however, is the nature of CAM research that is currently favoured by UK funders.
An influential report from the House of Lords clearly listed the priorities: efficacy, safety and cost. If millions are using alternatives, we need to know what works and where risks exist. Yet UK researchers conduct survey after survey, many of which are without real medical relevance. Being much more consumer-driven than any other area of medicine, CAM still relies heavily on anecdotes. The newspapers are full of reports about VIPs trying colonic irrigation, ear candles, cupping or anything else you can think of. The often gullible public is more than keen to follow their example. But what can anecdotes tell us? Do they prove that CAM works? Of course not. As a substitute for proof, anecdotes are virtually worthless. In conventional medicine, this has long been appreciated; it is about time that we also acknowledged it in CAM.
Answering the question "Does it work?" is more complicated than most enthusiasts care to admit. Take spinal manipulation, a manual technique to treat back pain. Because of its widespread use, it serves as a good example. Is the boom supported by evidence?
A recent project summarised 39 clinical trials. For patients with acute back pain, spinal manipulation proved to be superior only to sham therapy or interventions known to beineffective or harmful. It had no advantage over other treatments such as care by GPs, analgesics, physical therapy, exercise therapy or back school. For chronic back problems the results were similar. The authors' conclusion: "There is no evidence that spinal manipulation therapy is superior to other standard treatments for patients with acute or chronic low back pain."
If you suffer from a bad back, what does that tell you? One reading could be to keep your money and go to see your GP or physiotherapist. Continuing with the same example, on the issue of safety, about half of all spinal manipulation patients will experience mild adverse effects lasting up to 24 hours. Therapists are adamant that serious complications are extremely rare. But exercise therapy is virtually risk-free. Does that not imply that, in this instance, conventional medicine is better?
CAM advocates are confident about the economic implications of employing it on a broad basis. Sadly, the evidence does not support such optimism. Specifically regarding spinal manipulation for back pain, a recent cost evaluation suggested that it is about twice as expensive as normal medical care. Does this mean we are wasting our money on CAM?
Surveys may suggest that CAM is highly popular; research from focus groups may indicate that patients love it, but are we convinced it is superior, safer or cheaper than competing treatments? I am hopeful that, for some situations, the answer will turn out to be yes. But without further research we cannot be sure. Realising that research of CAM is vital is surely the most fundamental change in the recent history of CAM.
CAM has made huge advances in recent years, but the road ahead is still long. Consumers need to know which treatment they can trust, and researchers must supply the evidence for well-informed decisions. All of us are troubled by confusion and contradictions which are due to lack of conclusive evidence. Until this evidence is available, let's be patient, let's be constructively critical, and let's not forget good old common sense.
· Edzard Ernst is professor of complementary medicine at the Peninsula Medicine School at the universities of Exeter and Plymouth