If ever you need a reminder that the mind has a powerful effect on the body, just think of the placebo effect. This term became known in pharmaceutical trials, but actually the placebo doesn’t have to be a pill; it can be anything – from an injection to a device to an apple.

An apple would reduce pain for someone if they believed it would, because their belief would produce the brain’s own painkillers – the brain’s natural versions of morphine and heroin – called endogenous opioids.

So says dr David Hamilton. He received his PhD in organic chemistry and worked in research and development in the pharmaceutical industry, developing drugs for cardiovascular disease and cancer. He eventually left the industry to write books about harnessing the power of the mind and emotions to improve mental and physical health.

David says that it’s the endogenous opioids that reduce the pain, not the apple, and it’s the belief that produces the endogenous opioids. That’s why a growing number of researchers argue that the placebo effect should be used in clinical practice, instead of trying to eliminate it.

Too ‘woo-woo’ to be true for you? In his new book, ‘Why woo woo works: The science behind holistic therapies’, David shows how many of these therapies are supported by compelling scientific evidence.

He also uses scientific evidence in ‘The Little Book of Kindness’ to show that kindness changes the brain, impacts the heart and immune system, is an antidote to depression and improves relationships.

David says that the good feeling we get when we’re being kind to someone is due to elevated levels of endogenous opioids. They cause elevated levels of dopamine in the brain and so we get a natural high, often referred to as ‘Helper’s High’.

He explains that acts of kindness are often accompanied by emotional warmth, which produces the hormone oxytocin in the brain and throughout the body. Oxytocin causes the release of a chemical called nitric oxide in blood vessels, which expands the blood vessels. This reduces blood pressure, thereby protecting the heart.

Oxytocin reduces levels of free radicals and inflammation, two culprits that play a major role in heart disease. There have also been suggestions of the strong link between compassion and the activity of the vagus nerve, which regulates heart rate and controls inflammation levels in the body.

Kindness can neutralise fear because it creates oxytocin, which turns down activity in the fear centres of the brain. Kindness reduces the emotional distance between two people and so we feel more ‘bonded’. David says that this is actually a genetic thing; that ‘kindness genes’ were etched into the human genome. The stronger the emotional bonds within groups, the greater were their chances of survival.

Conversely, Kristin Neff says, “If you are continually judging and criticizing yourself while trying to be kind to others, you are drawing artificial boundaries and distinctions that only lead to feelings of separation and isolation.”

That is why kindness also means being kind to yourself. David says that many people who volunteer for charitable causes miss the “kindness to yourself” part. Even though being kind to others is good for us on a mental and biological level, too much can be detrimental.

He says that this can be seen from a study that examined the amount of time people spent volunteering. Once a person got to 16-20 hours a week, the effects of volunteering became negative. Beyond this threshold, it begins to feel like a job and something that’s expected of you. Many volunteers already have full time jobs that earn them their wage, so they’re burning the midnight oil.

Another reason, one that is relevant to those who care for loved ones who are ill, is that the concern and fear for their situation, plus the emotional demands of caring while maintaining a household, can be extremely stressful. For many this is not a choice, but a role forced onto them by circumstances. 

I guess you can steadily go from ‘Helper’s High’ to ‘Caregiver’s Crash’ if you refuse to be kind to yourself . . . and then all the ‘good biology’ goes flying out the window along with major pieces of your mind.

Here’s to your health and sanity, girlfriend. You’re not just a bunch of neurons and hormones on autopilot. Your beliefs, attitudes and emotions matter. Profoundly. It’s not all in the mind. It is, in a sense, but your body keeps the score.