The autonomic nervous system acts largely unconsciously and regulates bodily functions, such as the heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal.
This is a nervous system that can function entirely on its own, away from the central nervous system, which is composed of the spinal cord and the brain.
The autonomic nervous system is composed of two key branches; the parasympathetic – a.k.a. the “rest and digest,” or the “chill out” one – the branch that allows us to rest, relax, digest and recharge, and the sympathetic – a.k.a. the “fight or flight,” or the “do something!” stress-releasing adrenaline/cortisol one – the branch that is responsible for our stress response and survival by controlling functions such as the heart rate, blood sugar and cortisol, which help us get away from a threat quickly and efficiently. The vagus nerve is the parasympathetic nervous system’s primary nerve.
The vagus nerve is a squiggly, shaggy, branching nerve connecting most of the major organs from the brain, through the heart and the gut down to the colon. It is
the longest nerve in the body, and it comes as a pair of two vagus nerves, one for the right side of the body and one for the left. It’s called “vagus” which is latin for ‘wandering’ because it wanders among the organs. The vagus nerve is largely responsible for the mind-body connection, for its role as a mediator between thinking and feeling. When people say ‘trust your gut’ they really mean ‘trust your vagus
A healthy parasympathetic nerve response, which is governed by the vagus nerve, is essential for our mental wellbeingand physical health. This is because when we are functioning from a parasympathetic ‘point of view’, we are able to repair, digest and assimilate nutrients in our food and regenerate. The parasympathetic nervous system plays a role in heart rate, sexual arousal, digestion, urination, and gastrointestinal activity.
We have evolved to be in this state most of the time, however, due to the pressures of modern life and chronic stress, many of us are continuously in a sympathetic state, where we are constantly in a physiological ‘fight or flight’ mode.
The vagus nerve works to control inflammation. It alerts the brain to release neurotransmitters when inflammatory proteins are present. These neurotransmitters help the body repair then reduce inflammation. Vagus nerve dysfunction is linked to obesity, chronic inflammation, seizures, abnormally low heart rate, fainting, and gut issues.
Poor mental health such as depression, anxiety, panic attacks and insomnia, are all symptoms of poor vagus nerve function, which are often a result of environmental factors such as stressful situations and trauma.
The Gut-Brain Connection
The vagus nerve is essentially the ‘bridge’ between the brain and the gut, facilitating a bi-directional communication between the two organs. A crucial part of facilitating this communication and maintaining a healthy vagus nerve is the bacteria that live in the digestive system; microorganisms such as bacteria, yeast and fungi impact the production and functioning of neurotransmitters and inflammatory processes, which modulate brain activity. Eighty percent of the information transmitted by the vagus nerve flows from the body to the brain. Whereas twenty percent are transmitted from the brain to the body. Researchers have found how stress inhibits the signals sent through the vagus nerve and causes gastrointestinal problems. Symptoms such as the suppression of stomach acid and digestive enzyme production, as well as increased gut permeability (leaky gut), slower bowel transit time and nutrient malabsorption are often experienced when under chronic stress. On the other hand,
we also see how ‘gut instinct’, influenced by external factors such as stressful environments, alert the brain by triggering an emotional response such as fear and anxiety.
How to support vagus nerve function
Working to strengthen your vagal tone will help with mood, digestion, and overall well-being.
Here are a few ways that to help stimulate the vagus nerve and parasympathetic nerve activity:
Probiotics and prebiotics for Gut Health
The brain and gut are in constant communication via the vagus nerve. Which is why gut health and mental health are so intrinsically linked. If you suffer with digestive issues and/or food sensitivities – reflect upon whether these bouts of indigestion or stomach issues tend to be accompanied by mood swings, anxiety, brain fog and depersonalisation. If the answer is ‘yes’, it’s time to take greater care of your gut, as over 80% of our immune system is actually located within it! Healthy gut bacteria help to create signalling molecules, which are communicated via the vagus nerve to
the brain and keep inflammation at bay. Bacteria are also capable of creating neurotransmitters such as serotonin and dopamine. Eating fermented foods such as sauerkraut and kimchi, drinking kombucha or kefir that are rich in beneficial bacteria, help to maintain equilibrium in the gut. In addition, eating a wide variety of vegetables and fruits can help to provide prebiotic fibres for bacteria to break down, which provides them the essential fuel they need to maintain themselves and create the metabolites that positively influence brain function.
Loving kindness meditation
Meditation and mindfulness can be great health tools, due to the positive effect they can have on the nervous system. However, loving kindness meditation goes a step further by encouraging visualisation that generates ‘warm and fuzzy’ feelings of compassion and gratitude. This type of meditation is rooted in Buddhist tradition and seeks to promote four key experiences of friendliness, compassion, gratitude, and equanimity.
Stimulating the vagus nerve to the heart has a powerful effect on slowing the heart rate. And this is what relaxes us. The vagus nerve is basically listening to the way we breathe, and it sends the brain and the heart whatever message our breath indicates. Breathing slowly, for instance, reduces the oxygen demands of the heart muscle and our heart rate drops.
Our body senses your breathing and adapts its heart rate in response. When we breathe in the sensory nodes on our lungs send information up through the vagus nerve and into the brain, and when we breathe out, the brain sends information back down through the vagus nerve to slow down or speed up the heart. So, when we breathe slowly, the heart slows, and we relax. Conversely, when we breathe quickly, our heart speeds up, and we feel amped, or anxious. It’s specifically the exhale that triggers the relaxation response. Vagal activity is highest, and heart rate lowest, when you’re exhaling. If you find yourself in a stressful situation if you consciously slow down your breathing just for one minute, you can put yourself in a calmer state, to be able to better communicate.
Whilst breathing is a process that happens automatically, without the need for us to think about it, it is also a process that we can control. Deep belly breathing, and in particular, the lengthening of the exhale, can have an immediate impact on the nervous system, stimulating the vagus nerve and therefore the parasympathetic response. One of the easiest and most accessible breathing techniques is the box breathing exercise. Sit or lay down and breathe in as much as you can. Hold it for a second or two and then release. Repeat this 5-10 times. You’ll feel much more relaxed afterwards.
Yoga. Research has shown tremendous benefits of yoga for increased vagal tone, stress reduction, and trauma recovery. Yoga focuses on diaphragmatic breathing and extending the length of the exhale. The breathing and movement of yoga helps with digestion and has been shown to increase GABA levels. Gamma-aminobutyric acid (GABA) is a neurotransmitter, or chemical messenger, in the brain. It blocks specific signals in the central nervous system, slowing down the brain. This provides a protective and calming effect on the brain and body. Improving GABA levels will
stimulate the vagal tone.
Cold Showers. Cold showers can greatly improve vagal tone. Cold water immersion also allows us to become one with our body in an intense meditation. in the morning it is a great way of providing the body with a natural high. When you step into a cold shower you will not be thinking about work, relationships, or the stresses of life, you will simply be reacting with your entire being to the cold. This means heavy breathing and an excitation within the nervous system and heart, there is no time to think or be anywhere else except in your body.
The first thing that happens when your entire body gets extreme cold water is that the nervous system becomes shocked, and blood rapidly moves inwards towards
the internal organs to keep them warm and protected. This results in constriction and tightening of the nervous system. To transport this blood to where it needs to get in the body the heart must instantly react, and it gets very excited. This results in the lungs having to breathe very powerfully and very deeply. As you adjust to the cold, the sympathetic nervous system lowers and the parasympathetic system gets stronger directly affecting the vagus nerve. It is important to breathe all the way down to your belly, and visualize energy flowing throughout your body and all the way down to your fingertips and toes. The breathing pumps the body and shakes our main arteries and veins; this pumps blood throughout the body and stimulates excellent circulation. Take a cold shower whenever you need to refocus on your body or need a lift.
Craniosacral therapy directly addresses the cranial nerves (the vagus nerve is the 10th cranial nerve) and helps to shift the body out of a fight or flight state. Over time this can help to ‘rewire’ the nervous system by increasing vagal tone and allowing the balance between sympathetic and parasympathetic to reach a healthy equilibrium.
This is the simplest and most accessible way for a person to work on their vagal tone. Gargling mechanically stimulate the vagus nerve by vibrating the muscle fibres at the back of the mouth in the throat area. In the morning gargle some water as hard as you can. You’ll know you’ve stimulated the vagus nerve when you begin to get a tear response in your eyes.
Singing works the muscles in the back of the throat which stimulates the vagus nerve. Just make sure to sing at the top of your lungs for this effect to take place. ‘Aum’ or ‘Om’ mantra is particularly effective for cultivating a sense of calm, and is said to send out purifying, positive vibrations to the environment around you.
Laughter. Laughter releases a ton of neurotransmitter which improves vagal tone. Laugh hard and often.
Aromatherapy. Essential oils such as lavender and bergamot have shown to increase heart rate variability which improves vagal tone.