LIFESTYLE

Get to know the vagus nerve, your body’s in-built superpower

13 August, 2022 . 0

Like a personal bodyguard, your vagus nerve you develop a healthy stress response, keeping your wits sharp and triggering immune response.

The vagus nerve is the longest cranial nerve in your body — cranial nerves originate in your brain and you have 12 pairs.

The word “vagus” means “wandering” in Latin; and this aptly named, hard-working nomad wanders around your body sending out sensory fibres from your brainstem to your organs.

Rheumatologist Dr Daniel Lewis says the vagus nerve is the captain of our parasympathetic nervous system, which controls the body’s ability to relax and balances time spent in the highly stressful fight or flight mode, controlled by your sympathetic nervous system.

“It’s the master surveillance sensing part of the body, responsible for 80 to 90 per cent of the nerve trafficking signals into the brain,” Dr Lewis explains.

“It’s how the brain knows what’s going on inside you.”

“The vagus nerve has a huge influence on your heart, your lungs and your gut, and an influence on your stress response — you’re not going far without it,” Perth GP Dr Joe Kosterich adds.

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Here are 9 fascinating facts about the vagus nerve to get you started.

1. It prevents inflammation

The vagus nerve operates a vast network of fibres around all of your organs, like little spies.

When it gets a signal for inflammation, such as the presence of cytokines, science has found it alerts the brain and draws out anti-inflammatory neurotransmitters that regulate your body’s immune response.

2. It boosts memory

Extending prior findings in animal studies, a 2021 study from a team of German scientists found non-invasive vagus nerve stimulation enhances our long-term recollection of emotionally relevant events or information.

3. It helps you breathe

The vagus nerve is the major sensory channel from your lungs and airways to the brain, and so controls pulmonary function (how well your lungs work) and regulates respiration, including normal breathing.

4. Relax after stress

“Slow deep breathing can stimulate the vagus nerve and bring stress down,” Dr Lewis says.

“Breath in slowly for a count of four and out for a count of six to eight.

“The average normal breathing rate is between 12 and 14 per minute but this reduces it to six or seven.”

5. It plays a role in digestion

“The vagus nerve helps manage the complex processes in your digestive tract,” Dr Kosterich reveals. “It stimulates the release of stomach acid that’s necessary for digesting food, and causes the stomach muscles to contract and push food into the small intestine.”

6. It might help learn new skills

University of Colorado researchers found “a direct connection” between the vagus nerve, the cholinergic system (that regulates certain aspects of brain function) and motor cortex neurons that are essential in learning new skills.

7. It’s responsible for that ‘gut feeling’

As well as being the information superhighway that basically lets your brain “see” what’s going on, the vagus nerve sends information from the gut to the brain (a bit like a walkie-talkie) about how you’re feeling — hence the saying, “gut feeling”.

8. It can cause fainting

There’s a thing called vasovagal syncope, which is when your vagus nerve overreacts to stress triggers and causes a sudden drop in your heart rate and blood pressure, Dr Kosterich says.

This can lead to you fainting (or, at least, the need to sit down and rest until your vagus nerve adjusts).

9. It can be stimulated as part of therapy

As science continues to explore the role the vagus nerve plays in our wellbeing, and in treating anxiety disorders and inflammatory diseases such as rheumatoid arthritis, ways to stimulate it are now a focus.

“There’s an explosion of new forms of research where you stimulate the vagus nerve for therapeutic goals,” Dr Lewis says.

Simple acts like humming, gargling, singing, deep breathing and even laughing can all help improve vagal tone, he adds.