Suckers: How Alternative Medicine Makes Fools Of Us All, by Rose Shapiro (Harvill Secker £12.99, pp272)

Trick or Treatment: Alternative Medicine on Trial, by Simon Singh and Edzard Ernst (Bantam Press £16.99, pp352)

I suspect that neither of these books will find their way to Prince Charles's bedside table, despite the fact that one is dedicated to him. Both set out to ask why, as a nation, we're spending £4.5 billion a year on alternative medicine, an umbrella term for therapies that are largely disproven or unproven, occasionally dangerous and often bonkers to boot. The prince is a passionate advocate of alternative medicine and the revelation that the animals of the royal household receive homeopathy is just one of the cherishable details that Rose Shapiro in particular is so adept at relaying.

Suckers - the title casts consumers as gullible and practitioners as vampiric in a way that many will find intensely irritating - is a troubling book. Horror stories abound and no matter how sympathetic one is to the notion of a more natural way of medicine (as a former herbalist, I'm more sympathetic than most), it is impossible to read even a page without being shocked by the stupidity, incompetence, arrogance and corruption of a great swath of those who practise alternative medicine. Take the Hopi ear candler who does not have a basic grasp of the anatomy of the ear or the healer who can 'cure cancer' by 'electronically zapping ... a certain parasite, for which I have found evidence in every cancer case'.

The belief in parasites amounts to a religious conviction among certain so-called medics, 'Dr' Gillian McKeith included, and Shapiro takes a delight in exposing alternative medicine's wackier tenets. Her explanation of homeopathy neatly encapsulates its absurdities: 'The typical 30c homeopathic dilution is equal to one drop of mother tincture in nearly a hundred million galaxy-sized balls of water,' she notes. The technique is made all the more mystifying when one realises that this water, which apparently 'remembers' the active material that once passed through it (strychnine perhaps) is dropped on a sugar pill and allowed to evaporate. 'How and why should water discriminate between remembering a homeopathic mother tincture and remembering, say, the soap used in Marilyn Monroe's bathwater or the saltiness of the prehistoric sea?' she wonders. 'Can water have a selective memory?'

At the heart of both books is an acute awareness of the need for medicine to be evidence-based, a belief shared by the more sensible alternative practitioners. It's not good enough for a therapy to be popular or to have been around for centuries - it must be proven to work and to be safe. Most alternative techniques - herbal medicine is a grudging exception - don't perform well in clinical trials, particularly the double-blind trial, in which neither practitioner nor patient knows if they are receiving a genuine treatment or not.

While Shapiro is a journalist, Singh and Ernst are scientists and their mainly dismissive conclusions are based on extensive, though bizarrely unfootnoted, research. In tones of quiet fury, they demolish the claims of acupuncture, chiropractic therapy ('there is no logical, rational or scientific reason why manipulating a patient's spine should treat, for example, allergies') and homeopathy.

While certain herbs, notably St John's wort, are acknowledged to be effective, the potential dangers - from interactions with prescription drugs to contamination with heavy metals, a particular issue with Chinese and Ayurvedic medicines - are also laid out. Two things are notably lacking: an acknowledgement of the problems of funding adequate trials and a discussion of the equivalent risks and inadequacies of conventional medicine. Though extensively tested, pharmaceutical drugs are scarcely devoid of side effects, and patient dissatisfaction with their treatment options is one of the many reasons why alternatives have become so popular.

Despite the apparent lack of rigorous evidence, complementary medicine has also become increasingly legitimised in the past decade. It is taught in universities, receives £500m a year from the NHS and is recommended by the World Health Organisation. As far as Shapiro is concerned, this is a disgrace. In many cases, she's right - the five British homeopathic hospitals funded by public money are a debatable use of NHS resources. But who's to blame? Alongside practitioners, her culprits include the government, the media and, provocatively, consumers themselves.

Patients seem determined to embrace aura cleansing and Vega testing no matter what sceptics say. This is partly due to a widespread misunderstanding of how the body works, combined with a pervasive sense of toxicity that a media fixated on health does nothing to quell. But it is also due to dissatisfaction with conventional medicine. Singh and Ernst write: 'It seems as though some doctors delegate empathy to alternative practitioners.' Their prescription - that doctors increase the average seven-minute consultation - is no substitute for the more substantial appeals of the holistic approach. 'Alternative medicine knows exactly how to make each user special,' Shapiro says. 'In the name of treating the whole person, it wants to know all about you - there is no detail of your life too insignificant to be of interest.'

The implication - that we spend billions each year on what amounts to little more than snake oil because our critical faculties are dulled by the pleasures of having someone listen to us - is deeply uncomfortable and not entirely true. Medicine is an art as much as a science and the sick clearly long for their symptoms to carry more meaning than the prevailing mechanistic model allows.

The patients who seek alternative practitioners are often described by doctors as 'heartsink': they suffer from chronic illnesses that respond poorly to conventional treatments or from a constellation of symptoms that are not easily diagnosed or treated. The problem is that, as one doctor told Shapiro, 'headaches, heartaches, backaches, aching feet, fatigue, anxiety and those vague burning pains in your legs at night - these are the nemeses of real doctors. Many people have these symptoms but the cruel truth is there is no reliable cure for any of them'. It's not an easy truth to swallow, but where there is no real evidence to the contrary it's infinitely preferable to the sugared alternative.