Sifting the wheat from the snake oil chaff, she considers acupuncture, chiropractic, energy medicine, several varieties of meditation and even faith healing, providing historical background and related scientific studies.

But she doesn’t stop there; she delves into the nuances of the placebo effect, the role the brain plays in how we experience illness and the enormous value of empathy in healing.

Interwoven throughout the chapters are interviews, mostly with people who aren’t obvious candidates for alternative healing. Ian has fibrodysplasia ossificans progressiva (FOP), an extremely rare condition that slowly turns tissue into bone.

This horrifying genetic mutation is incurable and progressive, but since working with an energy healer named Gloria, Ian lists 18 positive “body changes” from her treatment.

Danila Castelli experienced the 69th miracle healing at Lourdes, France, officially verified by the Catholic Church. After taking a bath there in 1989, she was spontaneously cured of pheochromocytoma, a non-cancerous tumour on the adrenal gland.

Indian scientists step up study of cannabis-based painkillers

Perhaps most impressive of all is Joe Pinella, who was in a devastating road accident that broke his neck and left him a quadriplegic for years before he made a complete recovery by following the advice of a qigong master. Clearly, these cases are not your neighbour whose chiropractor fixed his trick knee.

Warner listens respectfully to their stories, but she doesn’t just take them at their word. Like a good sleuth, she looks into their medical files, and what she discovers adds more to the picture without minimising the benefits they have obtained.

For all the value the sceptics provide in finding objective truth, sometimes in their need for academic certainty they lose sight of what matters to their patients.

As one doctor with multiple sclerosis tells Warner, “Studies which have not ‘proven’ the treatment to be beneficial but which suggest a major benefit look much more interesting when you actually have the disease.”

Moving among the various therapies, scientific research and personal accounts, the book proceeds in an engaging but not immediately predictable pattern.

There is a point about halfway that you may think to yourself, “What, acupuncture again?” – but just be patient. With more than 1,000 published academic papers, including numerous double-blind studies, acupuncture offers one of the best windows to understanding how alternative therapies actually work, with tantalising clues.

Like a great courtroom lawyer, Warner pieces together the evidence to make her case, block by block, piece by piece, until the reader can see the larger picture.

The underlying value of this layered approach becomes clear as consistent themes emerge.

If the big question is, do alternative medicines work, then the answer is frequently yes, but for a specific set of identified health problems (which are conveniently listed), under certain conditions and mostly for the symptoms rather than the disease itself.

So while they won’t cure cancer, they can have objectively measurable results for the chronic pain and depression that accompany cancer, which is no small thing.

Everything comes together to suggest that the connection between the mind and the physical body is much more complicated than medical professionals previously thought.

Henry Beecher’s landmark study of soldiers in the second world war, which led to the widely used practice of double-blind clinical trials, is particularly revealing.

In his 1955 paper titled The Powerful Placebo, he noted that while 83 per cent of civilian trauma victims asked for pain relief upon reaching a hospital, only 32 per cent of soldiers did. He hypothesised that pain is a function of expectations.

“To a battlefield soldier … the hospital is ‘a ticket to safety’. His troubles are about to be over, or he thinks they are.” But for a civilian, being admitted to the hospital was “the beginning of disaster”.

The most recent research Warner cites goes even further, hinting that the successes of “conventional” medicine may owe far more to the placebo effect than doctors are ready to admit.

Does that mean pain is all in your head? Not quite. A better conclusion might be that your brain interprets your condition and dispatches pain as a signal for your body to take action, but that, like a smoke detector, it sometimes fails to differentiate burnt toast from a real fire.

The good news is that we may now have more control in how we experience pain, or, as cognitive behaviour therapists might, say, “Pain is unavoidable, but suffering is optional.”

Dumbo the elephant believed he could fly when his friend Timothy gave him a “magic feather”.

The small miracle of Warner’s entertaining and highly useful book is that it gives you the tools to understand how alternative medicine works, so you can confidently make up your own mind.

Chances are you will come away convinced that such treatments can help, if not always for the reasons their practitioners believe. But in the end, if your life is measurably better, does it matter?