The Vagus nerve and why it is relevant

In our previous article, we learnt about the role of breath in maintaining balance in our Autonomic Nervous System (ANS). How the body is continually shifting between the Sympathetic Nervous state (SNS) and the Parasympathetic Nervous state (PNS).

In today’s society, many of us are stuck in this heightened SNS state, which could lead to chronic stress. Continual flooding of adrenalin and cortisol leads to inflammation, which is a risk factor in 75 to 90% of human diseases.

In this article, we discuss the role of the vagus nerve, and how we can use our breath to strengthen the vagal tone.

So what exactly is the Vagal nerve?

• It is the longest cranial nerve connecting the brain to the rest of the body. 
• This ‘wandering’ nerve starts in the brain stem and ends in the pelvis, connecting all major organs. 
• The vagus nerve plays a large role in voice, heart rate, breath rate, and digestion.
• The vagus nerve is responsible for vasomotor activity, and some reflex actions, such as coughing, sneezing and swallowing.
• Most of the vagus nerve fibres send messages from the body to the brain.
• The Vagus nerve is the main contributor to the PNS (rest and digest state).

Why do we need a healthy vagal tone?

• The vagus nerve is the informative link between nutrition and psychiatric, neurological and inflammatory diseases.
• When we say someone has a healthy vagal tone, their autonomic nervous system is resilient and capable of shifting between the PNS and SNS effortlessly. The logical brain is dominant, ensuring an appropriate stress response to various situations. 
• Once the “stressful” situation has passed, the vagus nerve activates the PNS, and balance is restored.
• Therefore a healthy vagal tone means emotional intelligence, greater connection, and better physical health. 
• For an in-depth article about the role of the vagal nerve, have a look at this site; https://www.frontiersin.org/articles/10.3389/fpsyt.2018.00044/full.

How do we measure a healthy vagal tone?

We measure the tone of our vagal nerve by measuring our Heart Rate Variable (HRV), which is a measurement of time and frequency between each heartbeat. The heart is constantly slowing down and speeding up in response to what is happening internally and externally. 

Generally speaking, the higher the variable, the healthier our vagal tone is, the more resilient we are to stress.

Low HRV is linked to high levels of cortisol, the main stress hormone. Low HRV is seen in physical and mental illnesses such as;

• Heart disease
• Stroke
• Cancer
• High blood pressure
• Alzheimer’s
• Diabetes
• Depression, anxiety, panic disorder and PTSD

Low HRV can also be seen in healthy athletes who are over-training, and people who struggle with sleep.

We can easily measure and improve our HRV, and the results are beneficial and long-term.

What do the Vagus nerve and breathwork have in common?

We know that the exhale is related to the PNS, but you may not know that the vagus nerve releases a neurotransmitter called acetylcholine with every exhale. Acetylcholine causes blood vessels to dilate and the heart rate to slow down. Acetylcholine in the brain benefits memory and cognition. 

So we can see the importance of slowing our exhale down.

A bonus of a slow breath is that it engages the diaphragm, which connects to the heart, so every time you breathe optimally, your diaphragm massages the heart.

Further benefits of a slow deep breath; 

• The heartbeat slows, so it has more time to fill up with blood. 
• The diaphragm innervated by the vagus nerve is activated.
• Inhaled air reaches the deeper parts of your lungs, so more oxygen is received.
• Carbon dioxide increases in the blood, which is good, because it helps dilate the blood vessels, thereby increasing blood circulation. Good circulation means more oxygenated blood to the brain. 
• More nutrient-rich blood to the brain helps clear away waste products, thus reducing the risk of stroke and increasing memory and focus.
• The rise of carbon dioxide in the blood caused by slow breathing is linked to stimulating the vagus nerve.

The ideal rate of breath to increase HRV is at a rate of 5 seconds per inhale and 5 seconds per exhale, resulting in 6 breaths per minute.

For further information on the vagus nerve, look at Dr Stephan Porges extensive research.

Oxygen Advantage has a great article on the connection between breath, HRV and the vagus nerve https://oxygenadvantage.com/science/vagus-nerve-stimulation/.

HeartMath is another brilliant resource; https://www.heartmathsouthafrica.co.za/about-heartmath-coherence-hrv/.

To get your vagus nerve working to your advantage, contact me today to set up some private breathwork sessions, or have a look at my website for the next available complimentary breathwork session, happening on the first Friday of every month https://mayuralife.com/product/complimentary-breathwork-session/.