The Belief Effect

Imagine being told the pills you're about to take contain nothing at all, just sugar, and then watching your symptoms ease anyway. Or drinking a milkshake and having your hunger hormones respond not to what is in the glass, but to the words on the label. These aren't tricks or tall tales. They come from carefully designed studies at Harvard, Stanford and beyond, and together they reveal something extraordinary: what we believe and expect can change the chemistry of our bodies.

More than "just" a placebo

A placebo is a treatment with no active ingredient, such as a sugar pill or a saline injection. For decades it was used in research simply as a comparison, and the improvements people felt were dismissed as "all in the mind". But scientists have since discovered that the placebo response is a real, measurable event in the brain and body:

• In a classic 1978 study, people given a placebo after dental surgery felt less pain, but when they were then given a drug that blocks the body's natural opioids, the pain relief disappeared. The placebo had worked by releasing the brain's own painkillers, its endorphins.¹
• In people with Parkinson's disease, a placebo injection triggered the release of dopamine in the brain, the very chemical the disease depletes, as clearly as real medication on brain scans.²

In other words, the placebo effect isn't imaginary. It's the body's own pharmacy, opened by expectation.

Placebos that work even when you know

Surely a placebo only works if you're fooled? In 2010, researchers at Harvard tested this by giving people with irritable bowel syndrome pills they were openly told were placebos, "like sugar pills", with no active ingredient. After three weeks, 59% reported adequate relief, compared with 35% of people given no pills at all.³ Similar "open-label placebo" results have since been found for chronic back pain, where people taking honest placebos alongside their usual care had less pain and disability than those who continued their usual care alone.⁴

Even the details matter. In one study, people given a placebo painkiller described as costing $2.50 a pill felt more pain relief from electric shocks than those told the same pill had been discounted to 10 cents.⁵

Your mind is part of your medicine.

The milkshake that changed a hormone

At Yale, researchers gave people the same 380-calorie milkshake on two different occasions. Once it was labelled "Indulgence: 620 calories" and once "Sensi-Shake: 140 calories, guilt-free". When people believed they were drinking the indulgent shake, their levels of ghrelin, the hunger hormone, fell around three times more steeply than when they believed it was the "sensible" one.⁶ Their bodies responded to what they believed they had eaten, not to what was actually in the glass.

It's a gentle warning about restrictive "diet" thinking: when we believe we are depriving ourselves, the body may respond as though we are. Enjoying real, nourishing food, without guilt, may be better for the body as well as the soul. (See Real Food, Real Health.)

The hotel cleaners who got fitter

Hotel room attendants are on their feet all day, lifting, scrubbing and pushing heavy trolleys, yet most of them, when asked, said they didn't exercise. In a Harvard study, half of 84 attendants were told that their work met the recommendations for an active lifestyle, with examples of how many calories each task burned. The other half were told nothing.

Four weeks later, the informed group had lost weight and body fat, and their blood pressure had fallen, even though, as far as the researchers could tell, they hadn't changed their work or their habits outside it.⁷ A larger study followed this up: people who believed they were less active than others of their age were up to 71% more likely to die during the following decades than those who believed they were more active, even when their actual activity levels were the same.⁸

When belief harms: the nocebo effect

Expectation works in both directions. The nocebo effect is when expecting harm causes harm. In clinical trials, people taking placebos regularly report the side effects listed for the real drug, from headaches to nausea. (See First, Do No Harm.)

In a remarkable British trial, people who had stopped taking statins because of side effects took a month of statins, a month of identical placebo pills and a month of no tablets, in a random order, without knowing which was which. Around 90% of the symptoms they experienced on statins also appeared when they took the placebo.⁹ The symptoms were real, but much of the cause was expectation.

The nocebo effect may also help explain electromagnetic hypersensitivity: in controlled tests, people's symptoms appeared when they believed a phone or Wi-Fi signal was switched on, whether or not it really was. (See Wired and Tired.)

Beliefs about stress matter too. In a large American study, people who reported high stress and believed stress was harming their health had a 43% higher risk of dying over the following years. People with just as much stress who didn't see it as harmful had no increased risk.¹⁰ (See The Cortisol Clock.)

Sham surgery and the power of ritual

Perhaps most astonishing of all, the belief effect extends to surgery. In a landmark trial, people with arthritis of the knee received either standard keyhole surgery or a "sham" operation, in which the surgeon made small cuts in the skin but did nothing inside the joint. For two years, the people who had the sham surgery reported just as much improvement in pain and function as those who had the real operation.¹¹

The healing power of being heard

Some of the most important research for any practitioner concerns the relationship itself. In another Harvard study of people with irritable bowel syndrome, all received sham acupuncture. Those who were treated with warmth, attention and confidence during a longer consultation did markedly better than those treated in a brief, businesslike way: 62% reported adequate relief, compared with 44% after the brief consultation and 28% of those on the waiting list.¹²

Time, kindness and being truly listened to are not optional extras. They are part of how healing happens.

Ageing well begins in the mind

In a study that followed more than 600 people in Ohio for over 20 years, those who held positive views about growing older lived, on average, seven and a half years longer than those with negative views, a bigger difference than that linked with low blood pressure or low cholesterol.¹³ (See A Natural Age.)

What the belief effect can, and can't, do

The belief effect is powerful, but it has limits. It works most strongly on symptoms the brain helps to shape, such as pain, nausea, fatigue, mood, digestive discomfort and stress. Placebos don't shrink tumours or cure infections, and positive thinking is never a substitute for the treatment a serious illness needs. Nor is it ever anyone's fault if they become ill. The lesson isn't that illness is "all in the mind", but that the mind is always part of the picture, and a powerful ally.

Putting your mind to work

• Notice your self-talk. "My work keeps me active", "this meal is nourishing me", "I'm getting stronger": the words you choose may shape your body's response.
• See stress as a signal, not an enemy. Your racing heart is your body preparing to meet a challenge. (See The Healing Breath.)
• Enjoy your food, without guilt, and eat slowly enough to savour it.
• Choose practitioners who listen, and give yourself time to understand your treatment.
• Build rituals of care: a cup of herbal tea, a daily walk, a moment of gratitude. Rituals tell the body that healing is under way.
• Train your mind. Meditation and coherence practices reshape the brain itself. (See The Sound of Stillness and Heart-Brain Coherence.)

At Rootwise, we give every consultation time, because we know that being heard is part of healing. We work with your body, your beliefs and your hopes, so that your mind, your treatment and your daily life all pull together in the same direction.