I came across this 2018 paper recently:

Meditation and yoga practice are associated with smaller right amygdala volume the Rotterdam study

The Amygdala – there are two of them, left and right brain hemispheres, are part of the Limbic System, which is our emotional regulation circuit.  Specifically the Amygdala are involved in processing warnings and threats – sometimes called the brains alarm bell – and they pass an alert to other brain areas, notably the Pre Frontal Cortex and Hippocampus which in turn decide whether to react to the stimulus or dismiss the warning – so called Executive Control.

So far so good, this is how our brains work behind the scenes.  However like any system things can go wrong.  Specifically the Amygdala can become hypersensitive to alerts, in essence seeing threats that are not there, and this tends to correlate with a weakness in the regulation of these threats by the Hippocampus and Pre Frontal Cortex.  This in turn means we over react to threats – and sees us experience stress and anxiety – in a rapidly escalating state,

The Rotterdam Study is a long term health study, and this research was on a cohort of participants in the the Rotterdam Study who reported practising yoga.

That the Amygdala were smaller in Yoga Practitioners is probably no great surprise, as we know Yoga helps with emotional regulation.  Broadly a smaller Amygdala is a less reactive Amygdala.

However what was a surprise was, in the words of the study “Those who performed meditation and yoga practices reported significantly more stress and more depressive symptoms”.  The authors of the paper do speculate a little behind the causes of this “Meditation and yoga practices are known for their stress-reducing intent, making it plausible that people experiencing stress make use of these strategies, and that practice could even be seen as a marker of stress”.  I would suggest there may be some different variables at play:

– First, people experiencing stress could be drawn to yoga as a way of handling the stress, as the researchers suggest.

– However as stress was measured by self evaluation questionnaire in the study, it may also be that Yoga practitioners are more aware of stress – literally better in touch with their emotions.

– Finally, and touching on Yoga’s shadow side, it can be that the work of yoga – not the yoga postures but the self refection, psychological and insight aspects – is quite tough, especially at the outset.  To quote an acquaintance of mine, “If yoga is so good for me, why do I feel so miserable all the time” – so might these stress systems be temporary?  Part of the effort (“Tapas”) of yoga practice over time (“Sadhana”), and a necessary step on the road to well-being?

Of course I’m straying away from research and into philosophy here, but the speculation is interesting.  The underlying message from this study though is yoga is good for our brains, even if we don’t always feel it.

However, whilst generally safe, yoga can draw out unwelcome emotions which underlines the need for a supportive yoga environment with a Yoga Therapist, such as myself, or a Yoga Teacher with proven evidence based mental health experience.