I’d really like to take a look at the vagus nerve in this article. It seems to be having a moment in all mind/body modalities and we hear the term bandied about frequently, but what exactly is it, why is it important and how best can we optimise its functioning to improve our health and well-being?
What exactly is it? The vagus nerve is actually the main nerve of our parasympathetic nervous system, which is in turn part of our autonomic nervous system.
The autonomic nervous system is responsible for the communication and integration both between various organs within the body and the body’s external communication with its environment. It enables the organism to react or respond to internal and external stimulus. The system consists of our brain, our spinal cord and our nerves, which carry nerve impulses both to and from the brain. We hear a lot about the nervous system these days, particularly in relation to stress management. The autonomic system is divided into three parts but for the purposes of this article I will zoom in a little on two – the sympathetic and parasympathetic system.
The sympathetic system is responsible for our capacity to deal with a threat, a stress or a strong impulse and many of you will be familiar with the ‘fight or flight’ response where, in response to an external stressor, adrenalin surges to enable us to either fight the threat or run away from it. This is an inbuilt response essential to our survival, ensuring we weren’t all eaten by wild animals. It gets our heart pumping, bringing increased blood flow to the body, gets our lungs pumping, so we have sufficient oxygen to fuel our actions, and raises blood sugar levels to provide energy for action.
Once the threat to our survival has been eliminated or successfully avoided, our organism needs to regulate and rest, this function is carried out by our parasympathetic nervous system. This system is our ‘rest and digest’ response; it slows our heart rate and kicks off our digestion and counter-balances the adrenalin, which was released during ‘fight or flight’, thereby returning us to a state of equilibrium.
In an ideal world we would spend most of our time with a happy homeostasis between the sympathetic and parasympathetic state, however the rise of chronic stress has many of us spending too much time with our sympathetic nervous system switched on. Many of us have gotten used to living in a state of heightened stress , where demands can be constant. Too long spent in this state weakens the responsiveness of our vagus nerve, it becomes rather redundant and begins to lose tone due to inactivation and our beautifully designed sensitive inbuilt regulation fails. Put simply, we are unable to switch off. Sleep becomes problematic, we find ourselves lying in bed at night, exhausted yet unable to sleep, with our brains whirring away in a manic monologue. We can all tolerate a little of this but if we get stuck in a kind of full- throttle sympathetic system activation, our health can really suffer. Being unable to switch into our parasympathetic mode not only leaves us in a constant state of anxiety; there can be far greater and more far-reaching consequences to our overall health as I will outline below.
The vagus nerve, also known as cranial nerve 10, is the longest of all the cranial nerves. True to the etymology of the word, it is a vagabond, wandering its way throughout the body. As it exits the brain, it splits into two branches, travelling down either side of the neck, becoming the left and right vagus nerves.
These branches travel on down into the chest and abdomen, branching further into multiple organs including your heart, lungs, liver, spleen, stomach, intestines and kidneys. The vagus nerves play a critical role in the maintenance of homeostasis or balance, in functions related to digestion, satiety, respiration, blood pressure and heart rate control.
Therefore abnormalities in the functioning of the vagus nerve can include a myriad of ailments, such as abdominal pain and bloating, IBS, acid reflux and GERD (gastroesophageal reflux disease). A poorly functioning vagal nerve can also cause negative changes to heart rate, elevated blood pressure and blood sugar, difficulty swallowing, dizziness or fainting, hoarseness, chronic cough and so on and so forth. The list is as extensive as the reach of this nerve.
The vagus nerve also influences the immune system and helps control the body’s inflammatory response. It regulates the production of our old friends the pro-inflammatory cytokines.
Eight per cent of our vagus nerve fibres carry information from our organs back to our brain…this is the dual super-highway aspect of the vagus nerve. It is the vagus nerve that links the gut with the brain, forming the gut-brain axis we hear so much about these days. In the gut the vagus nerve is activated by neurotransmitters produced by the gut microbiome and when functioning well it regulates anti-inflammatory pathways, which decrease intestinal permeability (leaky gut) This nerve is constantly sending information about the state of the body’s organs upstream to the brain. As you can see it plays such a vital role in the health of so many of our systems and is so pressurised by the stresses of modern society that it’s optimum functioning should be the focus of any health plan we make.
Simple suggestions to improve our vagal tone
Cold water exposure: Much has been written about the various physical and mental benefits of a cold dip but probably the greatest beneficiary is the vagus nerve. Whether you enjoy an icy dip or a cold shower or gravitate more towards a gentler approach and prefer a cold splash on your face in the mornings, cold water stimulates your vagal nerve pathways thereby reducing your body’s stress response. You could even try the currently fashionable practice of icing your vagal nerve. This involves placing an ice-pack or pack of frozen peas on your chest for about fifteen minutes, usually before sleeping at night.
Deep breathing: Deep and slow breathing with the emphasis on long, slow exhalations is a wonderful practice to help improve vagal tone and switch into the parasympathetic nervous system. This is something I have always made time for in my classes, as I feel it is an essential tool for self-regulation. Long exhalations, particularly if you add sound such as a sigh, enervates the vocal chords and larynx, which further stimulates the vagal nerve and brings about the state of relaxation so needed.
Gargling: Ok, an odd one I admit, but again it involves the activation of the vocal chords and larynx, which stimulates the vagal nerve. Singing and humming are included here as they too activate the vocal chords.
Improving your gut bacteria: This will improve the state of your gut-brain axis and help with vagal tone, making for a more efficient communication system. Eat plenty of prebiotic foods, which are high fibre foods such as leeks, asparagus, red onions, and oats to name but a few.
Include nuts and seeds, including flax seeds and chia seeds and fermented foods such as sauerkraut, miso , olives and cider vinegar (with the mother). And of course keep your consumption of processed foods low and avoid all highly processed foods and excess sugar.
Exercise: It relieves stress, it improves vagal tone, it produces anti- inflammatory myokines , releases endorphins, increases oxygen flow and reduces blood sugar. I write extensively on the benefits of exercise, here’s yet another reason to move your body! There is no end to the joy of exercise!
Massage: Massage is wonderful and a most enjoyable way to help stimulate the vagus nerve, especially moderate-pressure massage around the neck and shoulders. Reflexology is also very beneficial to aid the switching into the parasympathetic nervous system. Avoid very strong massage though, as it tends to activate the ‘fight flight’ response, particularly in more sensitive individuals who can tense up against the pressure.
Meditation and mindfulness: With its emphasis on slow, gentle breathing, meditation activates the vagus nerve, calms the neural network and slows down the heart rate. It is a wonderful way of working consciously with the parasympathetic nervous system to help counter-balance the stresses of life.
