The biology of the vagus nerve and stress management through mindfulness meditation
Catherine Lienemann ‘UA 27 and James Stellar
In a previous blog, we established that the vagus nerve does more than provide a parasympathetic (calming) output. It is what we call the “nanny camera” of the body, as it has 80% of its neural fibers that are input to the brain. We also compared it to oxytocin, which is well known for its calming impact on the conscious awareness that seems somewhat similar, e.g., oxytocin approach-oriented profile. Now we want to return to discuss whether (and how) the impact of the vagus nerve can manage the ever-growing stress heavily present in college students, specifically through well-known meditation techniques. After all, it is hard for the cognitive planning frontal cortex to sort out the limbic system’s evaluation of experiences like an internship if it is stressed. Importantly, in addition, stress affects our long-term health, creating inflammation and causing disease and poor health outcomes. Making stress management a goal every college student should attain.
Stressors are a natural stimuli that help our bodies and mind work through tough situations. From my experience (CL) as an EMT, we are taught that there are 2 kinds of stress. The first being Eustress, the good stress that helps you focus and problem solve. Like how an athlete feels when they’re trying to score a buzzer-beater, or when you’re trying to make new friends on campus and feel amazing after you finally make a connection. This kind of stress is helpful and makes the body feel good. The second kind of stress is Distress, which is a harmful and long-term response to stressors in your environment. Examples of some stressors that all people, including college students, encounter are losing a loved one, lack of sleep, and financial instability, which are long-term, compounding issues when nothing is handled appropriately. Distress occurs when the body and mind are overwhelmed, often driven by the brain’s amygdala(the fear center) without sufficient regulation from the prefrontal cortex, which normally helps modulate emotional responses and decision-making.
The chemical side: When we’re stressed, the brain activates the HPA axis, releasing glucocorticoids that normally suppress the immune system and reduce inflammation. Inflammation itself is a natural defense against infection or injury, but when uncontrolled, it can damage healthy tissue, may increase genetic mutation risk, and contribute to diseases like cancer. While glucocorticoids usually calm inflammation, they can sometimes promote it or lose effectiveness if cells stop responding. In short, acute stress may boost immunity, but chronic stress weakens it and often drives harmful inflammation. According to one article about inflammation in response to stress, they stated that stress is a “risk factor of 75%-90% diseases.”
Cognitive-emotional integration was mentioned above as an important element in how the planning frontal cortex reads what the limbic system is telling it about any plan it has and how it is going. While the Nobel prize-winning psychologist Daniel Khaneman, who gave us heuristic-driven System 1 and deliberative-planning System 2, was reluctant (JS personal communication) to attribute these System 1-type decision processes to the limbic system and frontal cortical system, we are not. In a recent long blog, we began to lay out how the various areas of the frontal cortex seem to be trying to read the limbic system. Here, the idea is that distress causes a disconnect in that helpful integration. But if the cognitive system tells the limbic system it is OK, that could turn distress into eustress.
Now, If that is a mechanism of calming, how does it involve the vagus nerve?
Polyvagal Theory: This theory was introduced in 1994 by Stephen W. Porges. The bare bones of the theory say that the vagus nerve is the communication highway between the brain and the body (like our previous blog discussing the gut-brain axis). The theory further suggests that our body is like a manual clutch-drive car with different “gears” or responses to stimulus; the first gear being supporting a calm demeanor and open integration mindset, and 2nd, 3rd, and 4th (fight, flight, and shutdown) are for perceived threats. These gears were designed, in contrast to reptiles, to “ support greater autonomic flexibility in service of social behavior.” Now, an adaptive feature of these gears for people is to support the higher level of perception, cognitive ability, and greater complexity of our social world–In other words, more complicated stressors. While this theory has some critics, we are embracing it here for its general principles, particularly in the clinical realm and in centering the vagus nerve in broader thinking about calming and even promoting healthy social behavior. After all, social behavior is a big part of what a college student’s experience as growth. Consider evaluating one’s major change with peers or joining organizations like CL did with her EMT involvement, etc.
Using this knowledge, you have to wonder, if the vagus nerve is the basis of how all our stress is handled, how can we use this to combat the stress of college and life? Well, Stephen Porges beat us to it with his term “Polyvagal-informed interventions.” These interventions work to open the ventral vagal complex (VVC), which is responsible for becoming open for social engagement and behaviors otherwise known as the approach-oriented profile we mentioned as written about in our last blog.
These interventions are already present in mediation and yoga techniques. Examples are using music or calming sounds that signal safety to the body or breathing rhythm practices which “stimulate vagal afferents” promoting the parasympathetic activity that calm the body. Using Porges’ “Somatic and relational theories” could also provide feelings of safety through touch and movement such as stretching, deep pressure posing, or whole body stimulation. I (CL) have personal experience with Aerial yoga, which is enjoyable and provides full body pressure and comfort through the use of a silk hammock swing.
Heart Rhythm Meditation and Vagal Tone: In our previous blog, we’ve explored how mindful breathing stimulates the vagus nerve, slowing the heart and calming the autonomic nervous system to promote parasympathetic activity. But does the depth of breathing influence these benefits? The short answer is yes. Yoga and meditation are less scientific terms for Heart Rhythm Meditation (HRM), which directly engages this biological pathway. HRM emphasizes deep, slow, and full breaths—drawing in as much air as possible—while focusing attention on the heart.
This HRM process likely stimulates the vagus nerve more strongly than the standard tidal volume of inspiratory breathing. The deeper pressure of the total lung capacity being met is essentially ringing the doorbell of the brain via the vagus nerve–reminding the brain to pay attention! Research suggests that this enhanced vagal activation improves heart rate variability (HRV), a physiological marker of resilience to stress, and contributes to greater emotional balance and overall well-being. Regular practice can therefore serve as a powerful strategy for managing stress that cannot easily be resolved through simple relaxation methods, especially the chronic or cumulative stress we experience in academic and everyday life.
The reason HRV-based regulation is so effective lies in its ability to reconnect higher brain structures with the body’s nervous system input. When this communication weakens, emotional responses can become exaggerated—leading to breakdowns or overwhelming stress reactions. Without adequate input from the body and vagal signals, the prefrontal cortex cannot properly regulate the amygdala, the brain’s center for fear and anxiety. As a result, our stress response can spiral into an unchecked “fight-or-flight” state.
Conclusion: We think the focus on the vagus and moving from distress to eustress is important. Our next blog will look at adverse early childhood experiences, distress, and how studying the vagus nerve might help either produce greater cognitive control over emotions or maybe better allow the frontal cortex to re-frame the troubling emotional aspects so they are not so troubling.
