With many countries worldwide experiencing an ageing population, global interest in brain health is at an all-time high. Keeping our brains healthy is a crucial part of our overall health, especially as we get older, when mental decline is common (and is one of the most feared consequences of ageing - I’m including myself in this).
A healthy brain is more than just the absence of disease. It’s about how well your brain functions in several ways including cognitive health (being able to think, learn and remember), motor function (being able to move well), and emotional function (being able to respond to and interpret emotions).
In the last decade there have been some very cool (very scienc-y description) studies exploring the role that conscious breathing practices play on improving our brain health. I've compiled some of my favourites into two key areas:
Functional health - improving learning, recall, perception & more
Physical health - lowering oxidative stress, improving blood flow & preventing Alzheimer's
[Obviously I’m not a neuroscientist… so any mistakes are my own]
Improving Neuroplasticity
Neuroplasticity describes how what we experience reorganises and develops new neural pathways within our brain. It is the way the brain changes during our life to learn, adapt and recover.
Organisation & Learning
In this study, researchers used intracranial EEG (literally connecting electrodes directly to the brain itself - instead of only attaching them to the scalp!) to explore the impact of nose & mouth breathing on electrical brain activity.
What they found is that nasal breathing synchronises electrical activity in our piriform cortex (sense of smell), our amygdala (emotion processing) and hippocampus (learning & memory), while mouth breathing did not (1). Additionally, in a parallel experiment, they showed that people were more accurately able to recall memories when inhaling, especially when nasal breathing.
Key Takeaway
In short, nasal breathing helped synchronise brain activity and improve learning & accuracy.
Motor Skill Learning & Recall
Following on from that, this study showed that a 30-minute session of deep, alternate-nostril breathing (ANB) at between 8-10 breaths per minute, enhanced retention of a newly learned motor skill, both immediately and 24 hours after the session.
The basis of the study was their hypothesis was that there appears to be a connection between areas of the brain responsible for the learning and retention of motor skills and changes in brain activity in those same regions, when we voluntarily change our breathing pattern.
Key Takeaway
Why is this result a big deal? Often retention benefits seen shortly after learning do not always stick long term and because delayed retention tests (e.g. 24 hours later) are often better indicators of actual learning. (2)
While 30 mins of ANB is a long time, and the technique isn’t one I’d call a ‘simple breathing practice’, it opens the door to exploring the impact breathing exercises that induce a calm, alert and concentrated states have on our ability for learning and recall.
Processing & Perception
Lastly, this study compared the difference between nose and mouth breathing on brain wave activity and connectivity. Participants did 15 minutes of Samavritti Pranayama (Box Breathing) at 2.5 breaths per minute, then completed some psychometric tests.
While there was no meaningful difference in heart rate variability (and indicator of physical relaxation) between nose and mouth breathing, there were significant changes in brain connectivity across delta, theta and high-beta frequencies (see the diagram below).
Key Takeaway
I’m not even going to pretend I fully understand the study’s discussion, but what it does show is that nasal breathing created the ‘perception of an altered experience accompanied by an altered state of awareness”, (3) providing a meaningful contribution to the discussion of how our breathing impacts how we process information and experience our world.
“A better-connected brain is a more efficient brain.” - Steven Laureys, MD
Improving Brain Health
Nutrient delivery and waste removal are key for organ health, the brain is no exception. Below are several studies exploring how breathing exercises can help keep our brain physically healthy.
Oxidative Stress
Oxidative stress, where there is an imbalance between free radicals and antioxidants in our body, can cause damage to our organs, contribute to certain diseases like cancer, and accelerate ageing. This meta-analysis showed that slow (and fast) breathing exercises can lower oxidative stress markers and increase antioxidant levels in the body.
There were a variety of breathing protocols used, the commonality appeared to be techniques that 1) improved oxygen delivery to tissues and 2) enhanced strength and endurance of the respiratory muscles (4). Unfortunately (in my opinion), inspiratory muscle strength training generally requires a training device to provide breathing resistance, making it cost-prohibitive and impractical for some people.
Key Takeaway
However, other studies have shown that diaphragmatic breathing alone can lower oxidative stress, so the takeaway is… shut your mouth, breathe slowly, gently and nasally for your brain health!
Nutrient & Waste Flow
Cerebrospinal fluid (CSF) is a clear, colourless body fluid found within the tissue that surrounds our brain and spinal cord. It has many vital roles including providing cushioning,
delivering nutrients & hormones to the brain, and removing waste from the brain. Healthy CSF flow equals a healthy central nervous system equals a healthy human.
While CSF flow is 'sensitive and synchronous to respiratory movements' (5), this study investigated the impact of different breathing patterns on CSF flow. They put people into an MRI and had them breathe in four different ways; 1) slow breathing for 6-10 breaths per minute (no instruction on depth), 2) deep abdominal breathing, 3) deep diaphragmatic breathing, expanding the ribs and 4) deep chest breathing, expanding the front, back & sides of the chest.
Key Takeaway
What they found was that slow breathing increased the flow of CSF toward the head by 16-28% (chest 16%, slow-only 22%, diaphragmatic 23% & abdominal 28%). This suggests that a regular, slow, deep breathing practice may help deliver more nutrients and remove more waste in the brain.
Side Note
You might be wondering “why didn’t they also test fast breathing techniques?” While breathing faster and more intensely has been shown to also increase CSF flow, overbreathing (hyperventilating) reduces the levels of CO2 in our blood, constricting blood vessels and reducing blood flow to the brain. This is ok in the short term (it’s one of the reasons conscious connected breathwork works as a therapeutic tool), but if we’re looking at ways to improve overall health, my first preference is to optimise day-to-day breathing.
Amyloid Beta Levels
[FYI this one is nuts]
Alzheimer’s disease is one of the most common age-related neurodegenerative disorders. The buildup of amyloid beta proteins within the brain is known to be a critical trigger for the progression of the disease.
The hypothesis of this study was that ‘during ageing, the balance between the sympathetic and parasympathetic branches of the autonomic nervous system shifts’ and that ‘age-related increases in [sympathetic] activity along with decreases in parasympathetic activity might influence levels of amyloid beta peptides in the brain and body.’ (6)
They had two intervention groups (younger & older) breathe for 20-40 mins per day for 4 weeks. The breathing rate was slow (between 9-13 breaths per minute), to increase heart rate variability (HRV), but was tailored to each individual to ensure optimal heart rate oscillation (very cool).
Key Takeaway
Both the younger and older adults in the slow breathing group significantly reduced amyloid beta levels, meaning that ‘regularly practising slow paced breathing via HRV biofeedback may help keep plasma amyloid beta levels low throughout adulthood.’ (6)
The best part… ‘this study provides the first evidence of a behavioural intervention (my note: not a drug) that reduces amyloid beta levels compared to a randomised control group’... something drug companies have been chasing for a long time.
Summary
While there are many ways, and many breathing techniques, that contribute to a healthy brain, there are some commonalities:
Use your nose
Make it slower than normal (3-13 breaths per minute, I’d aim for under 10)
Breathe consciously for long enough (>10 mins)
Do it consistently (aim for 4 weeks or more)
Which is very similar to the optimal way to breathe to lower stress (that is no coincidence).
Breathing Exercise for Brain Health
Alternate Nostril Breathing (Nadī Shodhana)
Keep your inhale & exhale equal duration (either 4,4 or 5,5) and of equal force
Optional: ~2 second pause after the inhale
Make your breathing nice and smooth
Practice for 10 mins daily
Simple explanation:
Inhale through the nostril you just exhaled through
Start with an inhale through your left nostril
End exhaling through the left nostril
Less simple explanation:
Sit or lie in a comfortable position
Close your right nostril > Inhale through left nostril > Hold
Release right nostril > Close left nostril
Exhale through right nostril > Inhale through right nostril > Hold
Release left nostril > Close right nostril
Exhale through the left nostril
Repeat
Thanks
A huge thank you to The Breathing Diabetic for putting me onto these papers and his incredible ability to explain them to non-science folk. Definitely follow him on Instagram and sign up to his weekly newsletter.
References
Interested to learn more about the breath or want to learn how to go deeper? Join me at an upcoming workshops or explore my coaching program
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