The vagus nerve is the longest cranial nerve in our body. Vagus means wandering, and that is exactly how the nerve runs through both sides of your body. The vagus sends both sensory signals. These signals travel up and down the vagus nerve, controlling very important functions in your body. When you think mind-body connection, think about the vagus, because it connects your physical to mental body.
For example, the vagus nerve connects your brain to your gut. Signals from the gut can tell your brain when you’re hungry or full, activate the muscles in your stomach to start the digestion process (peristalsis), slow your heart rate, and activate your inflammatory stress response. If the vagus nerve is not working well, your body can be in a heap of trouble.
How the vagus nerve works:
- Controls the parasympathetic or “rest and digest” nervous system
- Regulates organ function like digestion, respiratory rate, heart rate
- Regulates reflexes such as swallowing, gagging, sneezing
- Allows your gut microbes from your microbiome to communicate with the brain (“gut feeling” come from this)
- Reduces inflammation
- Involved in seeing, hearing, talking (social engagement)
- Supports facial expression
- Supports development of memories
- Stimulates bile release from gall bladder
- Promotes sodium excretion from kidneys
When the vagus is working well, it is referred to as having good vagal tone. Good vagal tone is important to your mood, social connections, and even memories. When the vagal tone is poor, this means that something is impacting the messaging. You may feel brain fog, anxiety, or depression. So why would your vagus nerve not be working well? Inflammation can result in poor vagal tone due to:
- Chronic stress
- Chronic infection
- Dysbiosis (gut does not contain appropriate mix of normal microbes)
- Digestive disorders such as inflammatory bowel disease
Symptoms of poor vagal tone (more common than over-active vagal tone):
- Mood disorders such as anxiety, depression
- Throat issues (poor gag reflex, hoarseness)
- Heart arrythmias
- Gut issues (Irritable Bowel Syndrome, delayed stomach emptying, reflux, GERD)
- Slower recovery from stress
Symptoms of over-active vagal tone:
- Over-reaction to stress (vasovagal syncope or fainting from sudden decreased blood pressure, decreased heart rate)
How to improve your vagal tone:
- Activating muscles at the back of your throat by humming, singing, laughing, or gagging
- Deep breathing techniques
- Cold exposure such as splashing water on your face or a cold shower for a minute or so
- Mind-body practices like meditation, Yoga, Qi Gong
- Positive social connections[i]
- Massage, acupressure, acupuncture in specific areas
- Vagus nerve stimulation (with devices) is FDA approved for use for both depression and epilepsy[ii]
- Maintaining good gut health with probiotics, omega-3 fatty acids
Benefits of improving your vagal tone:
- Promotes feeling of satiety or feeling full after eating
- Lower blood pressure
- Reduce heart rate, respiratory rate
- Promotes ability to feel calm in stressful, non-threatening situations by helping you better interpret tone, facial expressions.
- Prevent inflammation and potentially reduce risk of chronic disease.
- Promotes glucose balance
- Helps with the body’s detoxification through the kidneys, liver, gallbladder and colon and other organs
Your provider can test your vagal tone through checking your gag reflex and measuring your heart rate variability (HRV). A good HRV means that your vagal tone is working well and that you are able to activate your parasympathetic or “rest and digest” system and react appropriately to stressors. Good vagal tone supports overall physical and mental health.
[i] Kok, B. E., Coffey, K. A., Cohn, M. A., Catalino, L. I., Vacharkulksemsuk, T., Algoe, S. B., Brantley, M., & 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. Psychological science, 24(7), 1123–1132. https://doi.org/10.1177/0956797612470827
[ii] Sun, L., Peräkylä, J., Holm, K., Haapasalo, J., Lehtimäki, K., Ogawa, K. H., Peltola, J., & Hartikainen, K. M. (2017). Vagus nerve stimulation improves working memory performance. Journal of clinical and experimental neuropsychology, 39(10), 954–964. https://doi.org/10.1080/13803395.2017.1285869
