Earlier this month I saw findings of a scientific study of 25 Australian veterans of the Vietnam War who had suffered decades of post-traumatic stress disorder (PTSD) – the mental illness with symptoms such as anxiety, depression, insomnia, flashbacks and emotional numbness. Counselling and other treatments hadn’t helped these men and many were alcoholics.
Fourteen of the group were given a five-day course of yoga, including movement, breath and meditation; the other 11 were on a waiting list for six weeks before also doing the course. The results were remarkable.
After the first six weeks, those on the waiting list had no change at all in their symptoms, but those who did yoga were significantly better. After six months, with both groups having done the yoga training, all had improved even more, scoring on average half their original level in a clinical measure of PTSD.
The study by clinical psychiatry professors Pat Gerbarg, of New York Medical College, and Richard Brown, of Columbia University, was just one of many research projects presented this month at Yoga, the Brain and Mental Health, the first conference in the UK bringing together yoga and mental health professionals to discuss research findings into the neurobiology of yoga.
Other studies presented included work with survivors of the Asian Tsunami, 9/11 and the war in Sudan. There were also reports of studies of yoga for people suffering anxiety disorders, depression, and survivors of child sexual abuse.
What became clear over the course of the three-day conference in London was that science has developed the technology to measure and explain some of the benefits that have been attributed to yoga over thousands of years. For example, with magnetic resonance imaging (MRI) scans it is now possible to observe and measure chemical changes in the brain over short and long periods of time as people practise yoga movement, breath and meditation.
In various trials, evidence has emerged of yoga being effective at helping people with a range of health problems associated with the mind or brain, including:
- Post-traumatic stress
- Anxiety disorders
- Alcohol dependency
- Attention deficit-hyperactivity disorder (ADHD)
- Eating disorders
It is thought the key to yoga’s success is that yoga treats mind, body, behaviour and – some would say – spirit simultaneously; any individual may respond more readily to any one of these aspects of a yoga practice.
Mind-body are one
During the conference I learnt in some detail how brain and body communicate with each other constantly, chemically. While our mental state affects our physical state (fear causing breathlessness, fast heart beat, and sweating for example), it is also true that through the physical aspects of yoga you can use your body to affect your mind. To see what I mean, try this:
Simple breathing exercise
- Sit comfortably on a chair or on the floor with weight of legs supported by the floor and your back long and at ease, chest slightly lifted
- Close or partially close the eyes
- Notice your mind and what you are feeling
- Breath in for a slow count of 5
- Breath out for a slow count of 5
- Continue breathing this way for 5-10 minutes
- Return to your normal breath, notice your mind and what you are feeling
Whenever I include this practice in my yoga classes I almost always notice a feeling of calm and quiet descend on the class. I don’t think it’s my imagination, but when we open our eyes at the end everyone looks a little more smiley!
So what is going on physically? Essentially, yoga is intervening in our body’s ability to handle stress. It helps to create a healthy balance between two aspects of our nervous system. One part (the sympathetic nervous system) activates the “fight, flight or freeze” response that we need to survive in moments of great danger. The other (the parasympathetic nervous system) activates “rest and digest”, telling us we are safe and all is well.
These two systems need to be balanced – with the parasympathetic system in normal circumstances being dominant over the sympathetic nervous system. But for many people, the balance has switched and we are in frequent, if not constant, states of stress.
Three key elements of yoga – breath, mindfulness meditation, and the body awareness associated with asana (postures) – bring these systems back into balance. Researchers have been testing various hypotheses for how this works, including by:
- Stimulating the vagus nerves, affecting parts of the brain responsible for our perception of feelings
- Affecting parts of the brain responsible for releasing stress hormones adrenalin and cortisol, the “pleasure” hormone dopamine, and “cuddle” hormones oxytocin and vasopressinof
- Increasing the presence of GABA – a chemical that “calms down” physical reactions in parts of brain that are perhaps overactive when we are stressed
- Improving heart rate variability, that is our brain’s ability to send the appropriate message to the heart about whether it needs to beat faster or more slowly
- Improving the ability of the most highly evolved parts of our brain responsible for thinking, judging, reasoning, and imagining (the cortex) to control the more ancient reflexive parts of our brain concerned with our stress responses (limbic system).
According to Dr Sara Lazar, a research psychiatrist at Massachusetts General Hospital, there is even evidence that continued yoga practice causes structural changes in the brain. She has conducted trials in which regular mindfulness meditation (a core part of any yoga practice) increases the amount of grey matter in several parts of the brain, including:
- Insula – used in connecting sense, thoughts and emotions
- Pre-frontal cortex – used in working memory, selective attention, interaction between thinking and feeling, and moral decision making
- Left hippocampus – used in regulating emotions, learning and memory
She also found that over time regular meditators had reductions in the size of their amygdala – the part of the brain primarily responsible for the “fight, flight, freeze” stress response.
This is a huge and growing field and I very much hope November’s conference will be the first of many. Huge thanks to Heather Mason, founder of The Minded Institute who was the driving force behind it.
If you are interested in finding out more, I found the work of the following researchers particularly interesting: