I have an old friend with a long and complicated relationship with food. Several years ago she answered an ad in a woman’s magazine. She filled out a questionnaire, sent off a sizeable chunk of cash, and received back, on the basis of no discernible evidence whatsoever, a list of her likely food intolerances. Overnight she slashed wheat and dairy from her diet. It was a melancholy sight, watching her kiss farewell to cheese and chocolate, denying herself at a stroke a significant slice of her daily pleasure.

I recently attended a stakeholder meeting on direct-to-consumer marketing of screening tests, organised by my colleagues at the BMA’s Board of Science. Doctors had been expressing concerns about the unregulated marketing of these tests, and their impact on patients and the NHS, and the meeting wanted to test the water. I admit to being slightly sceptical at first. To a liberal like me the world can seem overregulated. Although I figured my friend had been duped about her intolerances, I wasn’t sure she had been greatly harmed. There is after all a pleasure in denying ourselves pleasures. My scepticism did not last. Screening is a long established public health tool, but it is not without its ethical problems. It involves approaching apparently healthy – or at least asymptomatic – individuals and inviting them to undertake a test or survey from which they may derive some benefit. The UK’s National Screening Committee sets out a number of criteria that need to be met before an NHS screening programme can be introduced. These include the requirement that the results must provide useful, and not just interesting, information and that the benefits must outweigh the harms.
 
Enter the commercial purveyors of screening tests. They seem not to have heard of the NSC’s ethical criteria. We were shown a flier from one such company that invited the good townspeople of Bedford to visit their town hall on a given Saturday and to be screened, for a three figure sum, for a terrifying quartet of potential disorders: stroke; irregular heartbeat; peripheral arterial disease and abdominal aortic aneurysm.
 
What the flier did not say, however, was whether there was any correlation between the test and their future health, whether the cure for any condition that might be identified was more harmful than the condition itself, in fact whether the test provided any useful data whatsoever. As one delegate mentioned in another context, as a result of screening there could be as many as a million American men who have had unnecessary interventions for prostate cancer.
 
Somewhat hesitantly, one of the panellists introduced a philosophical dimension. It would seem that we cannot be healthy, she said, unless we are constantly being fiddled with by doctors. It is a good point. The increasing tide of direct-to-consumer health marketing looks to be bringing about a commercially-induced sea change in our understanding of health. We are replacing the idea of health as agency – as the ability to fulfil key life goals – or health as a sense of wellbeing, or even, more searchingly, health as an underlying disposition toward the world, with a very different idea. Health becomes instead a permanently imperilled biological state that can only be maintained by means of expensive hypervigilance. It is health as paranoia, health as ceaseless anxiety, it is health that watches itself through the lens of a tireless endoscope, that peers in dreadful expectation at the monitor of a CT scanner. How long before life itself is reduced to a succession of diagnostic displays?
 
When I think of my friend and her intolerances I cannot help thinking that she uses food, in ways that are too complex for me to understand, to work out her place in the world, to deal with her emotions, to manage disappointment, to negotiate with her fate. There are those who find it easy to take money from people in her position. And if this is true of food, how much more true is it of health, for the shadow on an x-ray or the spike on a chemical readout, could be the very shape our fate has taken. I do not know if marketing of this type will be regulated in the future, but what I would say to anyone thinking of buying such a test is beware. There is a cold glint of cash in the eye of some of these outfits. And what they are selling is state of the art snake oil.

Julian Sheather is ethics manager, BMA. The views he expresses in his blog posts are entirely his own.