The Vagus Nerve

The Vagus Nerve

What is the vagus nerve?

The vagus nerve is one of the longest and most complex nerves in the body. It is also known as the tenth cranial nerve. It is the main part of the parasympathetic nervous system, also known as the “rest and digest” portion of the nervous system. This system controls body functions that are involuntary such as digestion, heart rate and respiratory rate. Stimulating the vagus nerve can have therapeutic benefits for certain conditions such as epilepsy, depression, and other disorders. ¹

How does the vagus nerve help regulate the nervous system?

The vagus nerve plays a vital role in regulating many essential bodily functions, including:
Heart Rate: It regulates the heart rate by sending signals to the sinoatrial node (the natural pacemaker of the heart) to slow down the heart rate during periods of rest or relaxation.
Digestion: It influences digestion by stimulating the release of digestive enzymes and promoting gastrointestinal motility. It also plays a role in signaling feelings of hunger and fullness.
Respiration: It helps control your breathing by sending signals to the diaphragm and other respiratory muscles.
Inflammation and Immune Response: It has anti-inflammatory effects and can modulate the immune response, potentially influencing any inflammatory or autoimmune diseases.
Communication: The vagus nerve forms a critical communication pathway between the brain and the gut, often referred to as the “gut-brain axis.” This bidirectional communication is involved in various physiological and psychological processes, including mood regulation and stress response. ¹,²

Why being in parasympathetic nervous system mode is preferred

It is preferred to be in parasympathetic mode compared to sympathetic mode (“fight or flight”) because it means that you are in a more relaxed state. It can reduce your risk of heart disease and stroke, increase your digestive metabolism, and decrease migraines. It can also lead to better emotional and overall physical health, and possibly even a longer life span.

One way to see if your parasympathetic nervous system is working properly is to look at your resting heart rate, take a deep breath in and hold it, and see how high your heart rate increases. When you exhale, if your heart rate drops back down to your resting heart rate pretty quickly, then your parasympathetic nervous system is working very well. If you inhale and your heart rate increases and stays high, that means your body is in a higher state of stress and your parasympathetic nervous system is not working properly. ³,⁴

How living in sympathetic nervous system mode is harmful to health

In situations that are often associated with chronic stress, the sympathetic nervous system can be continuously activated, known as the “flight or fight” response. This can be harmful to your health due to the prolonged activation of stress-related physiological processes. Here are some ways in which living in sympathetic mode can negatively impact health:
Chronic Stress: Prolonged activation of the sympathetic nervous system leads to chronic stress, which can have many effects on physical and mental health. Chronic stress has been linked to a variety of health problems, including cardiovascular disease, obesity, diabetes, gastrointestinal disorders, and weakened immune function.
Cardiovascular Health: The sympathetic nervous system increases heart rate and blood pressure to prepare the body for action. However, chronic activation of this can contribute to the development of hypertension (high blood pressure), atherosclerosis (hardening of the arteries), and an increased risk of heart attack and stroke.
Immune Suppression: Chronic stress suppresses the immune system, making individuals more susceptible to infections and illnesses. Extended sympathetic activation can impair the body’s ability to fight off bacteria, leading to more frequent infections and slower healing times.
Digestive Problems: The sympathetic nervous system inhibits digestion and diverts blood flow away from the digestive organs to support other bodily functions during times of stress. Chronic activation of the sympathetic response can lead to digestive problems such as indigestion, constipation, irritable bowel syndrome (IBS), and an increased risk of gastrointestinal ulcers.
Weight Gain and Metabolic Issues: Stress-induced activation of the sympathetic nervous system can disrupt appetite regulation, leading to overeating or undereating. Chronic stress has also been associated with weight gain, particularly around the abdominal area, and an increased risk of metabolic disorders such as insulin resistance and type 2 diabetes.
Mental Health Disorders: Chronic stress and sympathetic activation are closely linked to the development of mental health disorders such as anxiety, depression, and post-traumatic stress disorder (PTSD). Prolonged exposure to stress hormones like cortisol can negatively affect brain function and exacerbate existing mental health conditions.
Sleep Disturbances: Chronic stress and sympathetic activation can disrupt sleep patterns, leading to difficulties falling asleep or staying asleep. Poor sleep quality exacerbates stress and can contribute to a range of health problems, including impaired cognitive function and mood disturbances. ⁴,⁵

Natural ways to stimulate the vagus nerve

There are many ways to stimulate your vagus nerve. Some common examples would be mild exercise, meditation, yoga, listening to music, or reading. However, there are numerous ways to stimulate your vagus nerve and it looks different for every person based on whatever allows you to decompress and relax. It does not have to be something you spend a lot of time on, it could even be for a few minutes each day. ⁶ If you’re interested in tracking your stress level, check out this product in our store. It trains you to shift and replace emotional stress with emotional balance and coherence.

References

1. Breit S, Kupferberg A, Rogler G, Hasler G. Vagus Nerve as Modulator of the Brain-Gut Axis in Psychiatric and Inflammatory Disorders. Front Psychiatry. 2018;9:44. Published 2018 Mar 13. doi:10.3389/fpsyt.2018.00044
2. Browning KN, Verheijden S, Boeckxstaens GE. The Vagus Nerve in Appetite Regulation, Mood, and Intestinal Inflammation. Gastroenterology. 2017;152(4):730-744. doi:10.1053/j.gastro.2016.10.046
3. Bonaz B, Sinniger V, Pellissier S. Anti-inflammatory properties of the vagus nerve: potential therapeutic implications of vagus nerve stimulation. J Physiol. 2016;594(20):5781-5790. doi:10.1113/JP271539
4. Long C. How the parasympathetic nervous system can lower stress. Hospital for Special Surgery.https://www.hss.edu/article_parasympathetic-nervous-system.asp.
5. Won E, Kim YK. Stress, the Autonomic Nervous System, and the Immune-kynurenine Pathway in the Etiology of Depression. Curr Neuropharmacol. 2016;14(7):665-673. doi:10.2174/1570159×14666151208113006
6. Fisher JP, Young CN, Fadel PJ. Central sympathetic overactivity: maladies and mechanisms. Auton Neurosci. 2009;148(1-2):5-15. doi:10.1016/j.autneu.2009.02.003