Can the mind help heal the body? Award-winning science writer and journalist Jo Marchant talks about Cure: A Journey into the Science of Mind Over Body, how placebos can actually create biological change, training our immune system to respond to scents and tastes, and so much more

I'm fascinated with the mind-body connection, and award winning science writer and journalist Jo Marchant has written a revolutionary and fascinating book about her research on the subject. From the placebo effect (yes, it's real) to how our psychological state influences our illnesses, CURE could change the way you think about modern medicine. I'm honored to host Jo Marchant here. Thank you, Jo

Why haven’t more doctors embraced the neuroscience of mind-body therapies? Is it a fear that people will fall prey to charlatans and not get the medical care that they need? Or is the simply the way alternative healers present their cures?

I think there are several intertwined reasons for this. Much of the skepticism does seem to come from a fear that if we acknowledge a role for the mind in health, this will encourage people to believe in the vastly overblown claims of some alternative therapists. The mind cannot shrink a tumor, banish a life-threatening infection, or mend a broken spine. To pretend otherwise raises false hope and put patients at risk if they don’t get the conventional treatment they need. (I agree that we need to be clear about the limitations of the mind in health, but underestimating it is dangerous too. When scientists and doctors ignore or deny evidence that alternative therapies do help some people, this damages trust in science among the millions of people who feel they benefit from these therapies, and pushes them towards pseudoscientific explanations.)

Another reason for the reluctance to accept research in this field is that science in general is based on a reductionist, materialist worldview that goes all the way back to Descartes, in which subjective elements – thoughts, feelings, experiences etc – as seen as less “real”, and less worthy of scientific exploration, than measurable physical matter. For many fields of research this is a useful distinction, it helps us to get rid of observer bias in experiments, for example. But in medicine the way we feel is of crucial importance, and I think we have to find a way to take this more seriously.

Then there’s the fact that our medical system is based on evidence from clinical trials. We compare treatments against placebos (fake medicines) to make sure they work. That’s important, and works well for physical interventions such as drugs. But it means we underestimate the value of other components of care. This is partly because most trials are funded by drug companies. A more fundamental problem is that placebo-controlled studies are specifically designed to discount any effect of the mind – pathways such as expectation, stress reduction and social support – because these elements are all present in the placebo group too. Any approach that harnesses these mechanisms will automatically fail the trial, no matter how much it benefits patients.

We’re left with medical systems that spend more and more on physical drugs, while cutting staff numbers and squeezing appointment times. A lot of doctors would probably acknowledge that this is counter-productive, but they’re working in a system that doesn’t give them much choice.

 What was the most astonishing finding for you – and why?

There were many findings that surprised me. Placebo responses trigger biological changes. Reducing stress slows the progression of HIV. Loneliness shows up in the activity of our genes.

But perhaps the one that astonished me most was that we can train our immune systems to respond to taste and smell. This works through a process called conditioning, in which we learn to associate a psychological cue with a particular physiological response. The most famous example is Pavlov’s dogs: the Russian physiologist Ivan Pavlov repeatedly fed his dogs at the same time as sounding a buzzer, until they salivated just in response to the sound.

Similar processes work in humans too, with many aspects of physiology including the immune system. If you take a few doses of a drug that suppresses the immune system, for example, subsequently taking a look-a-like placebo will trigger the same response. Researchers hope conditioning can reduce drug doses (and therefore side effects and costs) in situations such as organ transplants, arthritis and cancer.

When I started to research CURE, I was intrigued by the ability of the mind to influence subjective symptoms such as pain and fatigue. But to discover that our perception of the environment can have immediate and dramatic effects on something as fundamental to our survival as the immune system – that blew me away.

What fascinated me was your writing about sometimes placebos actually perform as well or better than the traditional med they are replacing. How the, could an individual wean themselves off meds by trying a placebos – I know there is a company that makes placebos, but isn’t part of why they work believing that they are other than what they really are?

In many situations we are better off taking conventional medicine. Drugs generally work better than placebos because when we take them, we benefit from both the direct effect of the medication and any associated placebo response. There are lots of things we can do to maximize the placebo responses we experience with the drugs we take, from actively engaging with our treatment to finding a doctor we respect and trust.

However in situations where drugs aren’t very effective (and/or come with risks such as side effects and addiction) and where placebo responses are strong, then some patients might do better on placebo. Examples might include chronic pain, irritable bowel syndrome, depression, and the side effects of chemotherapy.

Scientists have generally assumed that for a placebo to work, we must be fooled into thinking it is a real treatment. But there is now evidence, in conditions including migraine, ADHD, depression and IBS, that placebos can still work even when we know we’re taking them (although perhaps not as well).

This may be because believing that a placebo will help us works even if we know it contains no active drug. Or there’s evidence that if receiving medical treatment makes us feel safe and cared for, this can ease symptoms such as pain regardless of what pill we take. A third mechanism is physiological conditioning (as described above), which works regardless of our conscious beliefs. Researchers suggest that for chronic conditions from pain to asthma to ADHD, alternating an active drug with a placebo should give the same therapeutic benefit with a lower dose of drug.

Alternative medicines offer another way to take advantage of placebo effects without active medication. For example, a German trial published in 2007 followed 1162 patients with chronic back pain. Some of them received real acupuncture, and some received placebo acupuncture (where the needles are placed at incorrect points, and don’t fully penetrate the skin). There was no difference between the two: a result that would traditionally be cited as evidence that acupuncture is worthless. But in this trial there was a third group. These patients received conventional care – a combination of drugs, physiotherapy and exercise – and they did barely half as well as those in the acupuncture groups. Acupuncture, whether real or fake, was a much more effective treatment than conventional care.

Ultimately, instead of relying on dummy pills and treatments we should be developing evidence-based interventions that harness the mind. In CURE, I describe some effective examples, from hypnotherapy for irritable bowel syndrome (IBS) to virtual reality therapy for burns victims in severe pain. But so far, few patients have access to these approaches.

 Aren’t all disorders and diseases stress-related – or at least exacerbated by stress?

It’s hard to think of a condition that isn’t directly or indirectly exacerbated by stress. Stress has wide-ranging direct effects on physiology, including the heart, gut and immune system. This can have dramatic immediate effects, such as diarrhea, panic attack or even heart failure. It increases the risk of adverse events during surgery. And over time, it puts pressure on the cardiovascular system, which can lead to heart disease, and triggers chronic inflammation, which disrupts wound healing, increases our susceptibility to infection and autoimmune disease, and contributes to chronic diseases from diabetes to dementia.

Stress can also exacerbate medical conditions in less direct ways, for example by increasing our sensitivity to symptoms such as pain, nausea and fatigue. And of course it feeds into our behavior, making us more likely to indulge in unhealthy habits (such as smoking and eating fatty food) and less likely to stick to our medication, all of which in turn influence our physical condition.

 You write that the drug companies are averse (obviously) to psychological cures over medicinal ones, but what can the average person do to put pressure on them or to encourage their doctors to be more open minded?

Buy them a copy of my book!

What’s obsessing you now and why?

I’m very interested in the effect of the body on the mind. Just as psychological cues can alter physical health, physical factors – such as diet, exercise, immune responses and sleep – influence our mental state. A simple example is when you’re ill with flu. You experience physical symptoms such as fever, sore throat and aching joints. But you also feel exhausted and miserable. These psychological symptoms are triggered directly by your immune response to the virus, probably as a protective mechanism to ensure that you rest and stay isolated.

The subtitle of CURE refers to the science of  “mind over body”, because this is the idea that I set out to investigate. But I soon realized that this concept isn’t really accurate. Rather than the mind ruling the body, each one inevitably reflects and influences the state of the other.

 What question didn’t I ask that I should have?

One of the questions that most intrigued me when I started researching this book is why placebos work. Why should simply believing we’ve been treated trigger the appropriate physical response?

There is not just one placebo effect but many, and they work through different mechanisms. But in general, it turns out that these responses reflect a much deeper evolutionary principle.

Sensations such as pain, fatigue and nausea evolved as warning signs: they tell us something is wrong and encourage us to change our behavior – to move away from a threat, to rest, or to seek help. Pain makes us remove our hand from a burning stove; nausea stops us from eating food that might make us sick.

These symptoms help to keep us safe, but they have a cost. If we’re feeling ill, we’re less able to escape from predators, for example, or to seek food. Researchers are discovering that the brain constantly engages in a kind of cost-benefit analysis, calculating what level of threat a situation poses, and therefore how severe the warning signals need to be. To do this, the brain takes into account physical signals from both our body – such as injury or the presence of pathogens – and our environment. We feel more fatigued than normal if the temperature is high, or if oxygen levels are low.

But a key insight – and I think this is one of the central messages of my book – is that our psychological perception of a situation influences these decisions too. If we break an ankle, the pain tells us to stop and seek help. If we feel alone or in danger, that pain is amplified. On the other hand, once we know we’re safe and being cared for, there’s less need for the warning signal and our pain eases. (Or in a life-and-death situation such as being chased by a predator, it might be suppressed altogether – now it is more important to flee than to rest.)

How ill or well we feel therefore depends not just on our physical body but on our mental state. How threatened or safe do we feel? Believing we have no hope for recovery, hearing on the radio that there has been a poison gas leak nearby, feeling alone or stressed: all of these can amplify or even create symptoms. On the other hand, taking what we believe to be an effective medical treatment or receiving supportive, empathic care tells the brain that the crisis is over. The warning signals are switched off, and we feel better.

For me, this means that although we should always listen to our symptoms, we don’t have to be ruled by them. And placebos, instead of being a mysterious, almost magical-sounding phenomenon, suddenly make perfect scientific sense.