Your Brain & CO²

How can you ‘clean’ your brain when you're awake? Many of us now know that a lot of essential physical and mental maintenance takes place while we sleep. This includes the ‘cleaning’ of the brain by virtue of Cerebrospinal Spinal Fluid flowing through spaces between neurons to wash away waste build-up from the activities of the day. This is marvellous, especially as it appears to play a role in the prevention of neuro-degenerative diseases such as Parkinson's and Alzheimer's. But can you do more than rely on cleaning your brain only during sleep if these diseases are a concern? And what do you do if your sleep is routinely challenged? There seems to be cause for optimism. 

Previous research has already pointed to the brain cleaning effects of slow, deep breathing¹, but a more recent study² also reveals something new: Intermittent CO² exposure appears to offer the same benefits. Let me explain. 

For various reasons, we're almost conditioned now to regard carbon dioxide as exclusively negative and yet we can't get by without it. Yes, we exhale excess CO² when we breathe, but did you know this ‘excess’ amounts to just 15%? We hold onto 85% because we need it. The oxygen-rich haemoglobin in our red blood cells releases that oxygen when carbon dioxide is present. When this happens, oxygen is delivered to where it's needed: muscles, tissues, organs. If you remember learning about the Bohr Effect in your school science lessons, this information won't be new to you, but for most of us it’s quite a mind-shift to realise that without adequate CO² in the lungs and blood, we can't be well oxygenated. 

And what about other effects of this gas? Did you know that carbon dioxide is a calming gas? It's vagotropic meaning it stimulates and helps to tone the vagus nerve³. 

And very many of us don't have enough of it! Over-breathing is increasingly common, 

resulting in too many of us breathing off too much CO². As the pace of life has quickened so has our breathing and whilst it's keeping us alive, it's no longer supporting our mental and physical health and well-being. This, the biochemical dimension of breathing, is what the Buteyko Breathing Method seeks to address with its primary focus on re-establishing normal, rather than exaggerated, sensitivity to the build-up of carbon dioxide. Almost all of the exercises I use with my students involve intermittent hypercapnia, in other words, short bursts of tolerable air hunger, resulting in a modest increase of CO² in the blood and lungs. So, each time the exercises are practised, some brain clearance may be taking place!:

“Breathing practices that elicit oscillatory CO₂ may drive vasomotion and CSF flow through the perivascular and interstitial spaces.”²

In other words, breathing exercises that cause CO₂ levels to rise and fall may help create rhythmic changes in blood vessel size, which could help move cerebrospinal fluid through spaces around blood vessels and between brain cells. 

I don't know about you, but the revelation that simple exercises which work on breathing biochemistry (many breathing techniques miss this vital dimension) to restore healthy breathing patterns whilst also bringing balance to the autonomic nervous system AND potentially cleaning the brain sounds like an absolute gift! During my 30 years or so of chronic insomnia, this would have given me a little bit of hope and agency over a situation that seemed to be completely beyond my control. And in doing so, might I have slept better? I'll never know for sure, but the experience of recent years suggests that I probably would have. 

Future students will most definitely be apprised of this encouraging new discovery. As for those I've already had the privilege of working with, I hope they read this and keep up the good work!

~ Annette Henry 

☆Buteyko Breathing Method 

☆Oxygen Advantage Functional Breathing and Breathing for Yoga