A Vagus Nerve Survival Guide to Combat Fight-or-Flight Urges

Medically accurate illustration of the vagus nerve.

Source: Sebastian Kaulitzki/Shutterstock

All too often, the readily accessible power of the vagus nerve to lower anxiety and reduce inflammation is overlooked and underestimated. I’ve written posts here that highlight practical ways to tap into the ability of your vagus nerve to combat the cortisol-producing stress response of fight-or-flight.

In 1921, Nobel Prize-winning physiologist, Otto Loewi discovered that stimulating the vagus nerve caused a reduction in heart rate by triggering the release of a substance he coined Vagusstoff (German for “vagus substance”). This substance was later identified as acetylcholine and became the first neurotransmitter ever identified by scientists.

The vagus nerve is the prime driving force of the parasympathetic nervous system which regulates our “rest-and-digest” or “tend-and-befriend” responses. On the flip side, to maintain homeostasis, the sympathetic nervous system drives the “fight-or-flight” response. Ideally, within your autonomic nervous system, the tug of war between these two polar opposite mechanisms creates a "yin-yang" type of harmony marked by homeostatic balance.

From a simplified evolutionary perspective, one could speculate that our ancestors relied on the sympathetic nervous system to kickstart neurobiological responses needed to hunt, gather, and ward off enemies. Conversely, the parasympathetic nervous system probably fortified our innate drive to nurture close-knit human bonds, procreate, and build survival-based cooperative and supportive communities.

Unfortunately, the Toffleresque “future shock” of the 21st-century digital age, marked by too much change in too short a time, is causing our evolutionary biology to short circuit by throwing our individual and collective nervous systems out of balance.

Recent studies show that all too often, social media and other modern-day factors exacerbate perceived social isolation and feelings of being unworthy of love and belonging. Additionally, the individualistic "every man for himself" zeitgeist undermines collective “tending-and-befriending” and can put someone's fight-or-flight response in constant hyperdrive with no reprieve.

Luckily, there are some easily accessible and highly effective drug-free ways for you to activate the vagusstuff-producing power of your parasympathetic nervous system by stimulating your vagus nerve.

Vagus nerve stimulation (VNS) using an implanted device is one clinically proven way to achieve this outcome. But for some other practical, inexpensive, and readily available ways to stimulate your vagus nerve, I've curated a broad spectrum of empirical evidence into a one-stop-shop guide of maneuvers anyone can use. All nine techniques below are in the locus of your control. They also don't cost a penny or necessarily require any high-tech gadgetry:

1. Diaphragmatic Breathing Exercises
2. Tonic Levels of Daily Physical Activity
3. Face-to-Face Social Connectedness
4. Narrative Expressive Journaling
5. Gutsy Third Person Self-Talk
6. Sense of Awe to Promote Small Self
7. Upward Spiral via Loving-Kindness Meditation
8. Superfluidity and Secular Transcendent Ecstasy
9. Volunteering and Altruistic Generativity

Vagus means "wandering" in Latin. The vagus nerve is known as the "wandering nerve" because it has multiple branches that diverge from two thick stems rooted in the cerebellum and brainstem that wander to the lowest viscera of your abdomen touching your heart and most major organs along the way.

Source: Wellcome Library/Public Domain

As an ultra-endurance athlete, I spent countless hours monitoring my heart rate variability (HRV) and the robustness of my parasympathetic nervous system and vagal tone to make sure that I wasn’t overtraining. That said, until recently, I didn’t realize that this knowledge of HRV feedback could be applied as a public health tool.

A few days ago, I read about a new study by Kyle Bourassa and colleagues at the University of Arizona, "The Impact of Narrative Expressive Writing on Heart Rate, Heart Rate Variability, and Blood Pressure Following Marital Separation." The findings were published May 8 in Psychosomatic Medicine: Journal of Biobehavioral Medicine.

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The researchers found that a specific style of journal writing called “narrative expressive writing” helped reduce the harmful cardiovascular effects of going through a divorce. In a statement, Bourassa described the findings:

“The results suggest that the ability to create a structured narrative—not just re-experiencing emotions but making meaning out of them—allows people to process their feelings in a more adaptive way, which may in turn help improve their cardiovascular health.”

This study piqued my curiosity. I wanted to dig deeper and I was perplexed because, as far as I could tell, the Bourassa study didn’t discuss vagus nerve or vagal tone specifically. I’ve always associated HRV, the parasympathetic nervous system, and vagal tone as a triad that is intertwined. That said, adding a specific type of "expressive narrative writing" into this mix was a refreshing new angle with easy-to-apply prescriptive possibilities.

My initial attempt to unearth something fresh or useful that would complement Bourassa's findings was fruitless. Nonetheless, this study kept nagging at me. I found myself ruminating about a possible link between narrative expressive writing and the vagus nerve. One night, I tossed and turned because something in the back of my brain was trying to connect the dots of the Bourassa study with other research I’ve seen. Subconsciously, I knew there was some connection. Finally, this morning, on a long sunrise jog, I realized that the new study by Bourassa et al. shares some important similarities to the well-known research by Fredrickson et al. on loving-kindness meditation (LKM), prosocial behaviors, HRV, and the vagus nerve.

The 2013 study by Barbara Fredrickson and Bethany Kok of the University of North Carolina, “How Positive Emotions Build Physical Health: Perceived Positive Social Connections Account for the Upward Spiral Between Positive Emotions and Vagal Tone,” was published in Psychological Science. This groundbreaking research honed in on the vagus nerve and discovered that a high vagal tone index was part of a feedback loop between positive emotions, physical health, and positive social connections.

Identifying this correlation prompted me to stop in my tracks. I did a simple search for “HRV loving kindness vagus nerve” on my phone. Voila: A holy-grail type of study from 2016 by Igor Grossmann that had completely gone under my radar, “A Heart and A Mind: Self-Distancing Facilitates the Association Between Heart Rate Variability and Wise Reasoning.” (I will explore Grossmann's hypotheses in a future post.)

The reason I’m telling you all of this is twofold. First, after skimming Grossmann's research on HRV, the parasympathetic nervous system, egocentric impulses, self-distancing, and the vagus nerve on the jogging trail this morning I had a mini “Eureka!” moment. I made a quick mental list of nine vagal maneuvers to optimize heart rate variability and parasympathetic nervous system. Second, the aforementioned problem-solving experience I had over the past few days reaffirms one of my favorite quotations about the creative process, by Arthur Koestler:

“The moment of truth, the sudden emergence of a new insight, is an act of intuition. Such intuitions give the appearance of miraculous flashes, or short-circuits of reasoning. In fact they may be likened to an immersed chain, of which only the beginning and the end are visible above the surface of consciousness. The diver vanishes at one end of the chain and comes up at the other end, guided by invisible links.”

Anecdotally, I can reaffirm Koestler’s description of what it feels like to have a fresh insight, because I just had one. I’ve found that after fastidiously gathering a lot of crystallized knowledge and filling my head with tons of empirical evidence, an “Aha!” moment ultimately requires an incubation period that integrates fluid intelligence and cognitive flexibility.

From a neuroscientific perspective, I have a hunch that the process Koestler describes might rely on "unclamping” cerebral control of the prefrontal cortex and other cortical brain areas by allowing ideas to bubble up into consciousness from subcortical brain regions such as the basal ganglia and cerebellum.

I know my compilation of nine vagal maneuvers to stimulate the vagus nerve may not be earth-shattering. Nevertheless, it felt “miraculous” after days of wrestling with free-floating and dissociated ideas about the vagus nerve to finally connect the dots in a new and hopefully useful way.

Over the next few weeks, I will tackle each of these nine vagal maneuvers in a separate post.