The vagus nerve – an essential consideration for recovery
Stress is a common factor to be explored and supported with anyone who is suffering from chronic illness. The stress response aka the “fight, flight or freeze” response is activated anytime that we feel threatened, physically, mentally, or emotionally.
When we encounter stress, our body releases stress hormones like adrenaline and cortisol, designed to support the body as an acute response to enable us to fight, flee or freeze, in any moment. This response is an adaptive safety response, designed to keep us safe when threatened, but when chronically activated, stress hormones can contribute to a variety of health problems such as digestive issues, chronic pain, anxiety, depression, and many more.
Supporting the vagus nerve can help to counteract, or balance, the stress response, because the vagus nerve, when activated, activates the rest, digest, repair and detox, or parasympathetic part of the autonomic nervous system, to enable the body to rebalance and recover from the stressful encounter.
What is the vagus nerve and how does it support recovery?
The vagus nerve is a primary channel of communication between the brain and body, often referred to as the “gut-brain connection” and is primarily associated with the parasympathetic rest, digest, repair and detox division of the autonomic nervous system, as opposed to the sympathetic fight, flight or freeze, stress response.
It gets its name from the Latin word “wandering”, meaning it literally wanders around the body attaching to the main organs, beginning at the base of the brain, dividing into two, it travels behind each ear, over the mastoid bone (the bone just behind the ear) and runs across the chest and down into the abdomen, with connections to the larynx, trachea, bronchi, lungs, heart, liver, gallbladder, stomach, pancreas, kidneys, reproductive organs, and small and large intestines.
The vagus nerve oversees a lot of crucial subconscious bodily functions, including heart rate, digestive function, immune response, and control of mood, as well as vasomotor activity (constriction or dilation of blood vessels), and certain reflex actions, such as coughing, sneezing, swallowing and vomiting. The vagus nerve has also been shown to be involved in social engagement by allowing us to pick up on, or sense, other people’s emotional cues. The vagus nerve is a mixed nerve, which contains both sensory (afferent) nerves, about 80%, which are nerves that receive sensory information from the body and send signals back to the central nervous system, and motor (efferent) nerves, about 20%, eliciting actions, based on the information, to the organs it supplies nerves to. Gut reactions, like ‘butterflies in the stomach’ can be attributed to activation of the vagus nerve.
When the stress response is chronically activated, it can lead to low vagal tone, just like a muscle, the vagus nerve needs to be activated to maintain tone, so when a body has low vagal tone, the body then has a lower resilience to stress. Low vagal tone can be linked to symptoms and conditions such as gastroparesis, SIBO, IBS, weight gain, mood disorders, anxiety, panic attacks, tinnitus, depression, slowed heart rate, palpitations, seizures, difficulty swallowing and fainting, among others. Low vagal tone can also be associated with chronic inflammation because the vagus nerve plays a key role in the inflammatory response and immune system support. Vagal tone can be measured objectively by measuring heart rate variability (HRV), which is a measure of the time between each heartbeat, the more variable the time between each heartbeat is, the higher the HRV and the more resilient a body is. The lower the heart rate variability the lower the body’s resilience to stress and the less adaptive a body is to stress, so an individual may feel they have low resilience to stressful situations, both emotionally and physically.
Factors that can damage the vagus nerve
As mentioned, chronic stress, which can either be psychological or emotional from stress or trauma, or physical, such as bodily injuries, like accidents, traumatic brain injuries, operations, neck and back injuries and even poor posture can contribute to low vagal tone. Other factors to consider that can indicate low vagal tone or interfere with vagus nerve function, include poor gut health, which could be as a result of infections, intestinal permeability, checking for underlying stealth infections like bacteria, viral, parasitic infections, assessing intestinal motility, and considering environmental toxins such as mould, heavy metals and environmental chemicals and toxins. It is also important to consider dietary intake as a low nutrient dense, highly processed, high sugar dietary intake can all negatively affect the vagus nerve and lower vagal tone. Lastly, it’s important to consider sleep and over training or under recovery.
How can working with the vagus nerve support recovery?
Working with the body and working with the vagus nerve in practice can support vagal tone, supporting the body towards finding balance and towards recovery and optimal health. This can be done is various ways, which can include the following
Vagus nerve stimulation (VNS) devices
VNS devices are devices that can be applied to the skin and the device stimulates the vagus nerve transcutaneously (through the skin). Stimulating the vagus nerve can help to build vagal tone, helping the body to spend time in the parasympathetic rest, digest and detoxify state to support recovery. This should only be done through the guidance of working with a practitioner or GP.
Dietary and supplement interventions
Ensuring a whole food nutrient dense dietary intake to support inflammatory levels and support the anti-inflammatory dietary intake and supplementation such as omega 3 fatty acids, probiotics, and beetroot juice have all been shown to have a supportive role.
Breathing practices
Practicing deep or belly breathing, so ensuring that you expand your belly and diaphragm when you breathe, as opposed to shallow chest breathing, which seems to be something so commonly seen in practice.
Positive social connections, laughter (even forced belly laughter), the true smile of happiness (Duchenne smile) have all been shown to have a positive benefit on vagal tone and stress resilience. So, optimise spending time with those around you who make you laugh and smile.
Meditation is a great way to improve vagal tone, this can be supported with apps, such as Calm App, Insight Timer, or Heartmath, singing, humming or OM chanting can also stimulate the vagus nerve at the back of the throat, together with gargling or using a tongue depressor to stimulate the gag reflex
Cold therapy, such as an ice bath, or a cold shower on the back of your neck can be another way to improve vagal tone. This could be introduced by incorporating a short burst of cold water at the end of your shower, alternated with warm water, to build up tolerance, until ice baths or wild swimming can be incorporated.
Therapies other than nutritional therapy and functional medicine
Other therapies and hands-on healing practices, focusing on the body and mind such as somatic experiencing, EMDR, EFT, neurofeedback, cranial sacral therapy, chiropractic support, acupuncture, biofeedback, and psychotherapy, can also support the vagus nerve and increase vagal tone.
Closing
Therefore, when it comes to recovery from any illness or symptoms, whether acute or chronic, its important to consider your stress response and how that has contributed to your health status. By supporting your vagus nerve and vagal tone you can send messages to your body that it’s safe, and that its time to relax and de-stress, to enable it to carry out all the necessary functions of optimal digestion, detoxification, growth and repair, which are all crucial when supporting a body to rebalance and return to optimal health.
References
Borgwardt, S., Goebel-Stengel, M., Klinik Zerbst, H., Juergen Drewe, G., Breit, S., Kupferberg, A., Rogler, G. and Hasler, G., 2018. vagus Nerve as Modulator of the Brain-Gut Axis in Psychiatric and inflammatory Disorders. 9, p.1.
Colzato, L.S., Sellaro, R. and Beste, C., 2017. Darwin revisited: The vagus nerve is a causal element in controlling recognition of other’s emotions. Cortex; a journal devoted to the study of the nervous system and behavior, 92, pp.95–102.
Cross, M.P., Acevedo, A.M., Leger, K.A. and Pressman, S.D., 2022. How and why could smiling influence physical health? A conceptual review. https://doi.org/10.1080/17437199.2022.2052740, pp.1–23.
Holzman, J.B. and Bridgett, D.J., 2017. Heart rate variability indices as bio-markers of top-down self-regulatory mechanisms: A meta-analytic review. Neuroscience and biobehavioral reviews, 74(Pt A), pp.233–255.
Kim, H.G., Cheon, E.J., Bai, D.S., Lee, Y.H. and Koo, B.H., 2018. Stress and Heart Rate Variability: A Meta-Analysis and Review of the Literature. Psychiatry Investigation, 15(3), p.235.
Kok, B.E., Coffey, K.A., Cohn, M.A., Catalino, L.I., Vacharkulksemsuk, T., Algoe, S.B., Brantley, M. and Fredrickson, B.L., 2013. How Positive Emotions Build Physical Health: Perceived Positive Social Connections Account for the Upward Spiral Between Positive Emotions and Vagal Tone. https://doi.org/10.1177/0956797612470827, 24(7), pp.1123–1132.
Rosas-Ballina, M., Olofsson, P.S., Ochani, M., Valdés-Ferrer, S.I., Levine, Y.A., Reardon, C., Tusche, M.W., Pavlov, V.A., Andersson, U., Chavan, S., Mak, T.W. and Tracey, K.J., 2011. Acetylcholine-synthesizing T cells relay neural signals in a vagus nerve circuit. Science (New York, N.Y.), 334(6052), pp.98–101.
Rull, G. and Lobo, M.D., 2021. Is PoTS an Autoimmune Condition? Postural Tachycardia Syndrome, pp.163–170.
Taylor, A.G., Goehler, L.E., Galper, D.I., Innes, K.E. and Bourguignon, C., 2010. Top-Down and Bottom-Up Mechanisms in Mind-Body Medicine: Development of an Integrative Framework for Psychophysiological Research. Explore (New York, N.Y.), 6(1), p.29.
Thayer, J.F., 2009. Vagal tone and the inflammatory reflex. Cleveland Clinic Journal of Medicine, 76 Suppl 2(SUPPL.2), pp.S23-6.