The vagus nerve is the largest central nerve in the body. Meaning “wanderer” in Latin, the vagus nerve starts at the brain-stem and travels all the way to the abdomen, connecting the brain and the body.
As part of the parasympathetic nervous system, this nerve plays a crucial role in the body’s stress response. Essentially, when you find yourself in a stressful situation, your body releases hormones like cortisol and adrenaline and enters “fight or flight mode”, a survival response meant to help you react quickly to life or death situations.
Many of the stressful situations we find ourselves in are not life or death, however, and that’s where the vagus nerve comes in. The vagus nerve counters the fight or flight response, sending the signal to your body that the danger has passed and you can now rest.
The vagus nerve also helps regulate many other functions in the body, such as digestion, heart rate, and respiratory rate, as well as reflexes like sneezing, coughing, and even vomiting. Not to mention, it gets activated whenever you feel emotions like empathy and compassion.
One area in which the vagus nerve plays a particularly crucial role is the gut. In fact, the vagus nerve is largely responsible for what is often called the “gut-brain connection” because it directly carries information both ways between the digestive tract and the brain. This is why our emotions can have a direct impact on the gut, and vice versa. For instance, if you’ve ever felt butterflies or a pit in your stomach, or even had a “gut feeling” about something, then you’ve experienced your emotions affecting your gut.
Gut health has also been shown to affect mood and mental well-being; inflammation or irritation in the gastrointestinal tract can even be a factor in depression and anxiety. This is because, along with the vagus nerve communicating between your gut and brain, you also have what is sometimes called a “second brain” in your gut – your enteric nervous system (ENS).
The ENS, made up of hundreds of millions of nerve cells from the esophagus to the rectum, lines your entire gastrointestinal tract and works with the microbiota in your gut to control digestion. These microbiotas can even produce neurotransmitters directly in the gut and are responsible for 95 percent of the serotonin in your body. Therefore, it’s no wonder that the gut can be responsible for shifts in mood and mental wellbeing.
Along with its connection to stress response and the gut, stimulation of the vagus nerve is a viable treatment for symptoms of migraines, epilepsy, and even Alzheimer’s disease.
Vagus Nerve Stimulation (VNS) simply refers to the stimulation of the vagus nerve, whether manually or through electrical stimulation. VNS was first discovered in the 1880s when it was observed that massaging the carotid artery in the neck could suppress seizures. In the 1930s and 40s, electrical VNS was conducted in animal studies and was found to have an impact on brain electrical activity as well as having an anticonvulsant effect on dogs experiencing medically induced seizures.
Today, VNS is typically used clinically through the surgical implantation of a programmable pulse generator device, a device similar to a pacemaker that can stimulate the vagus nerve through electrical pulses.
The vagus nerve can also be stimulated without a device using various mindfulness techniques such as breathing exercises, meditation, and yoga. These exercises can lower your heart rate and slow your breathing, giving your body the signal to enter rest mode and activate the vagus nerve.
Similarly, cold exposure, laughter, singing and humming, and even experiencing ASMR (Autonomous Sensory Meridian Response) have been found to stimulate the vagus nerve and activate its positive effects. Taking probiotics and maintaining a healthy microbiome have been shown to help with vagal tone too, thanks to the gut-brain connection.
Maintaining a healthy vagus nerve and regularly stimulating it, whether through electrical stimulation or mindfulness exercises, can not only mitigate stress but also encourage emotional regulation, calmness, and even physical well-being.
The vagus nerve may not be a cure-all for mental health and wellbeing, but it is undoubtedly a powerful resource that anyone can tap into to boost both their emotional and physical health.