March 2025 letter -Vagus nerve

Our autonomic nervous system can be divided into two areas: sympathetic and parasympathetic nervous system. The sympathetic side increases alertness, energy, heart rate, blood pressure and respiratory rate.

The parasympathetic side, which the vagus nerve is very much involved in decreases alertness, blood pressure, and heart rate, and helps with calmness, relaxation, and digestion. As a result, the vagus nerve also helps with defecation, urination, and sexual arousal.

The vagus nerve is one of the 12 pairs of cranial nerves, perhaps the most complex of them. It is the longest nerve in the body, the vagus nerve starts at the brain stem, splits into two branches and travels through the neck, chest and abdomen. It transmits information to and from the brain to all tissues and organs in the body. Vagus nerve is a part of the autonomic nervous system, which consists of the parasympathetic and sympathetic parts. It is the main nerve of the parasympathetic nervous system, which controls many bodily functions, including control of stress and relaxation, immune response, digestion, and heart rate. It establishes one of the connections between the brain and the gastrointestinal tract and sends information about the state of the inner organs including our gut, to the brain

Main functions of the vagus nerve:

• Communication between the brain and the gut, our emotions play a big part here as can affect vagal tone, but there is also communication coming back. Elevated emotions such as love, joy, compassion and gratitude can strengthen vagal tone which reduces anxiety and stress

• Relaxation with deep breathing, the vagus nerve communicates with the diaphragm. With deep breaths, a person feels more relaxed. Deep, slow breathing stimulates the vagus nerve and lowers the heart rate, and this can be amplified through the rhythmic rising and falling of the belly during abdominal breathing. Try making your exhalations longer than your inhalations.

• Decreasing inflammation, the vagus one of many nerves that regulate the immune system, it sends anti-inflammatory signals to the body

Stimulating the vagus nerve can increase vagal tone, and thus have a significant positive effect on the functioning of your body.

In addition to deep breathing and meditation, exposing your body to cold conditions also increases stimulation of the vagus nerve. While your body adjusts to the cold, sympathetic activity declines, while parasympathetic activity increases

I quickly want to introduce you to the so called Polyvagal theory which was introduced by neuroscientist Stephen W Porges, in the 90s. The Polyvagal Theory looks at how the vagus nerve relates to our ability to connect and communicate with each other. It explains how the autonomic nervous system has three subdivisions that relate to social behaviour and connection. They are the ventral vagal branch which is connecting the brain stem to the face, oesophagus, bronchi, pharynx, and larynx, and the heart, the sympathetic nervous system in the spinal cord, the “fight/flight,” system, and the dorsal vagal branch which is also connected to the lungs, airways and the heart, but also many other internal organs including the gut, gallbladder pancreas etc.

All of these subdivisions have a different effect on our body and how we feel. For example, if the we feel that our environment is safe, the ventral vagal branch is active and we feel connected, positive, relaxed, free to be ourselves and express feelings in social situations, such as love, joy, friendship, happiness. In this situation, we use facial expression and a modulated voice pattern easily, our eyes are glowing and we have a firm and warm handshake. We appear energetic and confident. Internally, our heart rate is relatively calm, we breathe freely, and we filter out human language from background noise.

When experiencing stress and seeing the environment or our situation as dangerous we feel overwhelmed and unsafe, and our sympathetic nervous system, the “fight/flight,” system is activated. Our heart rate and respiratory rate increases, blood flow to the surface areas of the body is reduced while flow to the muscles in legs and arms is increased, glucose is released for more energy for the muscles, preparing us to escape, and stress hormones such as cortisol are released into the bloodstream. When in this situation, our handshake might seem too firm, we appear anxious tight or even overly energetic/hyperactive.

In the event of chronic stress, when this type of stress response becomes constant in our lives, and we continue to feel unsafe we hit the point of freezing or shutting down as the dorsal vagal branch is activated. In this situation, much of the capacities mentioned above are turned off, leaving us with far less ability to relate to the world socially exhausted and burned out. The emotions connected to this situation are depression, apathy, grief, low energy exhaustion. Our handshake might feel cold and clammy, we appear monotone, expressionless and often avoid eye contact.

Both of these reactions, the fight or flight and the dorsal vagal mode are very primitive reactions.

When we suffer with PTSD, post-traumatic stress, all of these subdivisions are reacting, not only to the safety or danger in the environment, but to an internal interaction between our current environment and the memories from past life events.  If there has been a traumatic event in childhood for example, in which we did not feel safe, an event in the present adult life might remind us of such an experience internally, and we may fall back on the more primitive neural systems of subconsciously needing to fight off, flee, or shut down in order to survive.

Each of us always experiences some degree of trauma in our early lives.  Whether there has been events that caused us great fear and a feeling of lack of support in a significant situation, or whether it was a series of events that gave us fear, confusion, or a sense of not being safe.  These experiences may remain in our nervous systems and emerge to add in different situations later in life.

We can learn to train our body and vagus nerve to help us activate the ventral vagal branch to be able to relax recover and feel safe. We can do this using different practices, one of the easiest ones is breathing exercises. Meditation is also very effective, but sometimes it can be difficult to meditate if the stress levels are very high and breathing exercises can be more helpful to get started. For example, try counting to 4 when inhaling deeply, then hold your breath while counting to 4, then exhale when counting to 4 and again hold your breath when counting to 4. This is a very simple exercise. The idea with this is to relax the diaphragm which relaxes the vagus nerve.

Meditation is very effective in changing our mood and emotions very quickly and reduces stress very quickly. Also touch is effective so usually treatments such as massage/ acupressure massage or energy treatments. Psychotherapy and trauma therapy can be very effective. The aim is to help us feel safe which is when we are able to relax.

Natural ways to stimulate the vagus nerve

• Exposure to cold by taking a cold shower or splashing cold water on your face

• Deep breathing

• Meditation

• Singing, you can also use singing or humming to activate your vocal cords and the muscles in the back of your throat, which are connected to the vagus nerve

There are also a few gadgets available to help. Sensate 2 is a portable meditation device and app that uses a combination of vibration and relaxing sounds to calm the mind. According to the manufacturer, the low-frequency vibrations target the vagus nerve effectively and reduces the physical symptoms of stress in just 10 minutes.

In addition to vagus nerve, please read about the importance heart coherence and heart rate variability.

Please note that it is also important to eat well, nutritious food and avoid sugar as well as different stimulants such as coffee and energy drinks. Of supplements, I usually recommend those supplements important for neuro functions, vitamin B (including B12, B1, B2, B3 and B6), vitamin C, Magnesium and some times also some adaptogenic herbs such as ashwagandha are recommended.

It is also good to try to recognise stress factors and causes in every day life and work on these.