The healing power of little white lies

By Jerome Burne, Financial Times

This review of Placebo: The Belief Effect appeared in The Financial Times on 18 January 2003.

"Optimistic lies have such immense therapeutic value that a doctor who cannot tell them convincingly has mistaken his profession," wrote a cynical George Bernard Shaw in Misalliance.

Many such similar jibes have driven doctors to outlaw placebos - the modern term for "optimistic lies" - from today's medicine. New drugs have to undergo clinical trials to show they are more effective than a placebo and the term "placebo effect" is used to dismiss any alternative treatment that appears to have an effect when Western physiology indicates that it shouldn't.

Yet the placebo continues to haunt our 21st-century mechanistic model of medicine. Numerous experiments have demonstrated its power. Simply believing that you are getting treatment can reduce pain, lift depression and relieve stomach ulcers. Some complementary and alternative practitioners claim that the mind can heal any condition - all you need for perfect health is to think the right thoughts.

There are two questions about placebos that need answering: how can the psychological state of belief have such a dramatic effect? And are there any limits to it? Dylan Evans' achievement is that he comes up with a radical theory about how the placebo effect works and, as a result, he is able to make clear predictions about the conditions for which placebos will and won't work.

He makes a convincing case for saying that, far from being a sort of psychological panacea, the placebo originated as a specific response by the immune system to receiving medical treatment. So, rather than doctors from the earliest times taking credit for the achievements of "optimistic lies", it may have been those very lies that brought the placebo into being.

Although some may regard the placebo as omni-potent, research suggests that it is most effective at reducing pain and swelling, bringing down fevers, lowering inflammation, stimulating appetite and alleviating anxiety.

It turns out that all these conditions are signs that a division of the immune system, known as the Acute Phase Response (APR), is at work. APR is a sequence of physiological changes that swing into action upon the detection of invading pathogens. Pain tells us something is wrong, fever makes it harder for bacteria to reproduce and swelling is a sign that the various immune defenders are rushing to the area under attack.

The purpose of APR is to hold the fort until a second part of the system, known as Acquired Immunity, can get going. This is far more sophisticated, capable of targeting specific bacteria and viruses, but it takes several days to deploy.

What then is the point of having a system in the body that can turn off a vital first line of defence against infection? Look again at those APR indicators. Aren't they familiar? They are precisely the symptoms that our most widely used drugs - painkillers - are aimed at: paracetamol to bring down a fever, corticosteroid to calm inflammation, and so on.

APR works rather like a smoke alarm. Because combating infection is so important, it often goes off unnecessarily; so, like the alarm, you can safely switch it off without the house burning down. Damping it down with a placebo or with drugs conserves your resources - activating APR is metabolically expensive, raising your temperature by one degree, increasing energy consumption by 13 per cent. What's more, if there is an infection lurking, it also speeds up the arrival of the Acquired Immunity cavalry, because a crucial weapon in APR's arsenal is nitric oxide. Unfortunately, nitric oxide actually slows down the production of the next wave of Band T cells, those responsible for identifying and hunting down specific invaders.

So Evans' idea is that humans long ago developed the ability to turn down APR when it seemed safe, and so reap these benefits.

Evans' thesis has all sorts of intriguing implications. Placebos should be effective for heart conditions - lots of inflammation - but not for cancer or infections. Since the placebo effect is dependent on belief, it may be impossible to scientifically define the optimum conditions for a placebo, since belief is so individual.

My only quibble is with his outdated bashing of complementary and alternative medicine. The notion that all drug-based medicine is effective and tested properly and the success of anything else is due simply to the placebo is simply wrong. There is good evidence, for instance, that treating arthritis or a loss of bone density with nutrition and supplements is safer and more effective than using drugs.