Getting To Know the Most Interesting Nerve In the Body & How It Can Help Fight Chronic Disease

By Dr. Jane Brewer

The vagus nerve might just be the most interesting nerve in the body. It starts from your brainstem and connects to almost every single organ in your body. This remarkable nerve is typically associated with creating a parasympathetic response in the body, which is the opposite of a sympathetic, or stress response.

The sympathetic nervous system is like the gas pedal in your car. It’s responsible for the fight or flight response, it speeds up your heart rate, slows down digestion, and down-regulates the immune system.

The parasympathetic nervous system is like the brake pedal. It’s responsible for the rest and digest response. It slows down the heart rate, increases digestive activity, and up-regulates the immune system.

In order to be healthy, we need both components of this automatic system to be functioning properly; in other words, the gas pedal and the brakes are both necessary components of the car. Our sympathetic system allows us to run from danger and deliver great athletic performance when it’s activated properly. Our parasympathetic system helps prepare our bodies for sleep, and improves digestion and absorption of the nutrients that keep us going.

What life is really about is balancing these subsystems of our Autonomic Nervous System. In our on-the-go world, it’s extremely common to live in a sympathetic-dominant state.This dominance is what leads many people down the path to chronic health issues such as hypertension, diabetes, and irritable bowel disease.

We can’t always control the stressors that surround us in our daily environment, but there are things we can do to help activate the vagus nerve and turn up the volume on our parasympathetic nervous system.

Cancer, Chronic Disease and the Vagus Nerve

The title of a study published in 2014 recently caught my eye: If you have an active vagus nerve, cancer stage may no longer be important.

The authors of this study used a metric called Heart Rate Variability (HRV) to monitor the activity of the vagus nerve. HRV measures changes in the rhythm in between heart beats, which has been shown to be highly correlated with vagus nerve activity.

The authors of this study were able to illuminate an important connection for us — that people high HRV scores, meaning high vagus nerve activity, had substantially lower levels of tumor markers present in their system than patients with low HRV scores, or low vagus nerve activity. This was true even when accounting for differences in age and treatment.

What does this mean? That even in more advanced stage cancer, higher vagal activity may even protect against adverse effects and increase the odds of recovery.


How to Improve Vagus Nerve Activity

The good news for all of us is that we have the capacity to increase the activity of our vagus nerve. This is one of the metrics we keep track of in our NeuroStructural Chiropractic practice, and it helps us gauge the function of our patients’ Autonomic Nervous System in response to their care.

A sampling of vagus-activating activities include:

  • Regular exercise
  • Proper nutrition and attention to gut health
  • Yoga
  • Meditation
  • Chiropractic

Increasing vagus nerve activity is, of course, not simply about treating cancer (or any other chronic disease). None of the methods above should be viewed as a stand-alone method of approaching chronic disease treatment. Working on achieving better vagus nerve function is about generating a higher level of resilience for your body, and better equipping it to deal with stress. This isn’t just beneficial for prevention of cancer and chronic disease, it can stand to benefit even the healthiest among us. Regardless of your condition, bettering your body’s ability to adapt to stress is always a positive thing.

Dr. Jane Brewer

Dr. Jane Brewer is a doctor of chiropractic who focuses on NeuroStructural Correction, which is unique in that it restores balance to the three core aspects of one’s body: the structural framework, function, and auto-regulation. Dr. Jane lives in Fort Collins with her husband Wes and when she’s not caring for patients, she can be found on a local trail for a hike or mountain bike ride. For more information about NeuroStructural Chiropractic, please visit