Pasteur is good, but don't forget pastor too

Medical science is going through a period of self-analysis and uncertainty, maintains D. J. Weatherall - but its condition is not terminal

Medicine's finest hour is the dawn of its dilemma... with mission accomplished its strengths are dissolving into disorientation." This view of the current medical scene, expressed recently by the historian Roy Porter, is a fair reflection of the mixed press doctors are receiving: the National Health Service in organisational and financial disarray; horror stories of clinical incompetence; breakthroughs in medical research that are never heard of again; increasing public disquiet over genetic manipulation and embryo research; and more.

Now James Le Fanu has twisted the knife in close on 500 pages of passionate criticism of modern medicine. To illustrate its remarkable rise in the 20th century he selects his top 12 advances and describes how they came about. This exercise is like trying to pick a best-ever cricket 11; Viagra just makes it as 12th man, while the discovery of insulin, the eradication of smallpox, and the control of poliomyelitis or river blindness are omitted.

The fact that Viagra scrapes in to the exclusion of measures that stamped out or partially controlled diseases that killed thousands of people throughout the world makes it an idiosyncratic choice, which, like much in this book, suggests that the problems of health care are restricted to richer, western societies.

However, although some tales have been told before, Le Fanu's accounts of the success stories of medical care are lively and well worth reading.

Le Fanu's belief that things started to go badly wrong about 20 years ago is based on four observations: some doctors appear to be disenchanted with their work; the costs of health care are soaring; complementary medicine is increasingly popular; and the community has become confused by conflicting advice about how to achieve a healthier lifestyle.

This state of affairs arose, he suggests, because after the grand period of drug discovery and clinical investigation, which led to the conquest of infectious disease and the evolution of high-technology medicine, the diseases that remained were either completely incomprehensible or the inevitable consequences of ageing. Hence the pharmaceutical industry went into the doldrums and clinical research became unfashionable and ineffective.

However, the real villains of Le Fanu's piece are clinical epidemiology and molecular medicine. While the study of diseases in large populations may have uncovered the relationship between cigarette smoking and lung cancer, similar attempts to unearth risk factors for other diseases have, it appears, been a complete disaster. Claims and counter-claims of the importance of diet, lifestyles and other environmental agents in the genesis of disease have left total confusion. Our efforts to reduce the levels of cholesterol in our blood, whether by taking tablets or by changing our lifestyles to those of our hunter-gatherer forebears, are based, Le Fanu believes, on nothing but a fairy tale. In short, this kind of "healthism" is breeding a generation of neurotic introspectives, obsessed with longevity at all costs. His solution is simple: every department of epidemiology shouldbe closed.

Molecular medicine, he says, has been equally disastrous. Apart from the generation of a few expensive therapeutic agents, the claims that understanding disease at the molecular level would play a major role in improving the health of society have come to nothing. Millions of pounds have been spent in what Le Fanu seems to regard as nothing more than a confidence trick that has led to very little understanding of disease process and nothing of benefit for patients.

All this, and the proliferation of extremely expensive high-technology treatment, at least some of which may be positively harmful, has left the medical scene in a state of disarray and near-bankruptcy. And, even worse, Le Fanu cannot see any light at the end of the tunnel, except for the possibility that some of the mysterious killers of middle life may still turn out to have an infectious origin.

Le Fanu writes in a persuasive style and his book is likely to be read widely. But is it a fair appraisal of the current medical scene?

Unfortunately, it suffers from a shortcoming common to a lot of popular science writing: in its efforts to convey the author's views and prejudices in an eye-catching fashion, it is highly selective in its coverage and oversimplifies almost every issue. This is well exemplified in the extremely naive explanation offered for the decline in clinical research. Had Le Fanu digested more of the thoughtful accounts of this subject that have been published in the United States and elsewhere over recent years, and tried to relate some of the problems of clinical investigation to the complexities of our diseases, not to mention the extraordinary mess that the American healthcare system has got itself into,his readers might not be left with the impression that it stems largely from the wishes of young doctors in the US to own a Porsche.

Le Fanu is right in believing that medicine is going through a period of self-analysis and uncertainty. The partial conquest of infectious disease earlier this century spawned a society that expected a great deal more of its doctors and believed that astate of permanent rude health was its birthright; illness and death were no longer considered to be part of the natural course of things. In western societies the conditions that replaced infectious killers, heart disease, stroke, psychiatric disease, cancer and the rest, were complicated and multi-factorial in origin. Quite often, when epidemiologists seek to find factors in our environments or lifestyles that might contribute to these diseases, very small effects are observed that, inevitably, are not always consistent.

But at least part of the blame for the dissemination of this "soft" information rests with Le Fanu's journalist colleagues: an article based on governmental advice, which appears under the headline "three pork chops a day cause cancer", may make the front page, but not if it is accompanied by the ifs and buts of environmental carcinogenesis, not to mention the more obvious question of how many of us indulge in such bizarre eating habits. Similarly, if the cholesterol story is carefully assessed from its biochemical, genetic and community aspects, it has undoubtedly shed important light on why our arteries clog up as we grow older.

Le Fanu's account of molecular medicine is equally limited. For example, for the account not to mention the extraordinary insights that it is giving us into the cause of cancer is, at best, careless. In discussing predictive genetics he touches briefly on the success story of the control of thalassaemia but, after writing it off as a special case, goes on to denigrate prenatal diagnosis because it is not so easy in the case of cystic fibrosis, a disease that is caused by many different mutations. But so is thalassaemia. The difference is that there are very cheap screening tests for thalassaemia, so that DNA analysis can be limited to babies of known risk. Screening for cystic fibrosis carriers depends on DNA testing; once its pathological mechanisms are better understood, cheaper screening methods will be developed.

Another disappointment of molecular genetics cited, again using a single example, is that patients with the same gene mutation may have a different clinical picture. Here, Le Fanu completely ignores work that is showing how the action of a few modifying genes may underlie this clinical heterogeneity and how this knowledge is being applied in genetic counselling.

Over the years many writers have castigated clinical practice and written obituaries for medical research; the pomposity of some doctors and the tendency, particularly at present, for scientists to oversell their wares make the profession a tempting target. In his extended preface to the play The Doctor's Dilemma , first staged in London in 1906, George Bernard Shaw attacked almost every aspect of medicine that concerns Le Fanu today: clinical science, statistics, the cost of healthcare and so on. And journalists have always been at pains to raise the spirits of their editors, and hence their readers. In March 1882, a few days after Koch described the discovery of the organism that causes tuberculosis, The Times announced that the end of that great scourge was nigh. Yet it was another 70 years, and after many false starts, before the development of streptomycin heralded the beginnings of definitive treatment; there is always a lag between work in the laboratory and its application in the clinic.

Medical science and practice are facing diseases of increasing complexity in an ageing population. While it is not clear when the fruits of the revolution in the biological sciences will come to the clinic, there have been similar periods of doubt and uncertainty in the past.

The good thing that has stemmed from our concerns is the realisation that,in the interim, we must regain the skills of good doctoring and pastoral care that have been lost in the era of high-technology medicine. It is this temporary failure on the part of conventional western practice that, more than anything else, has driven patients to complementary medicine.

Just as Shaw saw little future in the evolving fields of infectious disease and immunology at the turn of the century, the physicists of the time believed that their field was finished; both proved to be spectacularly wrong. Similarly, I suspect that Le Fanu may be premature in writing off medical science. It is undoubtedly going through a time of turmoil, but a more balanced and historically based account might have helped to put some of its present difficulties, not to mention its undoubted potential, into clearer and less destructive perspective.

Sir David Weatherall is regius professor of medicine, University of Oxford.