- The vagus nerve is the tenth of twelve pairs of cranial nerves and is also the longest in the body. In fact, the word “vagus” in Latin means to wander, it perfectly illustrates the path of this nerve that extends through various organs of the body.
This nerve goes from the brain through the face and chest to the abdomen
Vagus Nerve and Anxiety
To understand the link between the vagus nerve and anxiety, we must understand that the nervous system is formed by two “opposite” systems that constantly send information to the brain.
The sympathetic nervous system prepares us for action, therefore it mainly activates hormones such as adrenaline and cortisol.
The parasympathetic nervous system is related to rest and relaxation.
In practice, the two systems function as accelerator and decelerator. The sympathetic nervous system accelerates and activates us whereas the parasympathetic nervous system helps us to relax and slow us down, for this it uses neurotransmitters such as acetylcholine, that decreases the heart rate and blood pressure so that the organs may function more slowly.
Functions of the vagus nerve
The vagus nerve controls the parasympathetic system. It is involved in many functions, from the movements of the mouth to the beating of the heart, similarly, when it is affected it can cause various symptoms.
Some of the functions of the vagus nerve inside our bodies are:
It helps regulate the heartbeat, it controls muscle movements and it maintains the respiratory rhythm.
It maintans the functioning of the digestve tract, allowing thanks to the contraction of the stomach and bowel muscles we are able to digest our food.
It facilitates relaxation after a stressful stuation or it indicates that we are in danger and that we should not lower our guard.
It sends sensorial information to the brain about the our organ’s condition.
There are various techniques for stimulating the vagus nerve:
- Beng exposed to cold temperatures – It has been shown that being exposed to cold activates the vagus nerve because it stimulates cholinergic neurons that are crossing these innervations. In fact, an investigation carried out at the University of Oulu has revealed that being regularly exposed to the cold helps reduce the fight or flight response activated by the sympathetic nervous system.
It may be sufficient to take a 30 second cold shower a day or place a cold towel on our face. Some people also lay down on their stomach placing an ice cube on their nape. Other prefer to drink quickly a glass of cold water.
Diaphragmatic breathing – Most people inhale between 10 and 14 times per minute, which means that they breathe quickly and superficially. Ideally we should inhale 6 times per minute. Therefore, another very effective technique for vagal stimulation consists of breathing deeply.
Diaphragmatic breathing in particular activates the vagus nerve and the brain interprets this as the necessity to calm down, even though the nerve did not give this specific order. The mechanism is the same for which, if you close your eyes and touch your eyeilds with your fingers, you will perceive some flashes of light because the brain interprets it in this way.
With diaphragmatic breathing, we breathe more deeply and we take more air to the lower part of our ribcage, using the diaphragm correctly and promoting relaxation.
- Meditation, yoga and tai-chi – Meditation can increase the vagal tone. This has been proven by researchers from Oregon University who saw that only five days of meditation and awareness (Mindfulness) promote positive feelings towards oneself which cause the activation of the vagus nerve, while also modulating the activity of the parasympathetic nervous system, a much better result than those obtained with conventional relaxation methods.
Practices such as yoga and tai-chi are also ideal for stimulating the vagus nerve. Another study at Boston University has revealed that yoga increases GABA neurotransmittors, which promote the feeling of calm and tranquillity and help eliminate stress and anxiety.
How can a nervous system control so many different aspects?
Even though some aspects of vagal activity are mysterious, it is clear that ths nerve governs the parasympathetic nervous system, which helps control the body’s relaxation responses.
In simple terms, an increased vagal activity counteracts the stress response, involving the sympathetic nervous system. “The sympathetic nervous system is fight or flight, whereas the parasympathetic nervous system is about being more relaxed”, says Stephen Silberstein, MD, neurology professor and director of the Headache Center at Thomas Jefferson University Hospitals in Philadelphia.
Silberstein co-wrote an exhaustive analysis about the research on the vagus nerve.
He says that if vagal activity increases, the heart rate slows down and inflamation is diminishes, partly because it triggers the release of soothing chemicals from the immune system.
There is also evidence proving that activating the vagus nerve through electronic stimulation can produce a number of health benefits. “Depending on the frequency of the stimulation, we know that it can stop an asthma attack or an epileptic fit”, says Silberstein. “It can eliminate migrains or cluster headaches, and it can diminish the perception of acid reflux”