What Is The Vagus Nerve & Why Should You Care?
Maybe you know a little about it… Maybe you have never heard of it…
Either way, the VAGUS NERVE is one of the most important systems in your body. This NB explores why and how this vital (and massive) nerve system matters so much.
THE VAGUS NERVE: The Key to your Gut-Brain Axis
If you have been experiencing periods of inexplicable anxiety, low mood, or even decision fatigue, the cause might be quite a surprising one, buried deep in the core of your body.
In recent years, scientists have been researching the effects of the connection between our gut and our brain, known as the Gut-Brain Axis. This is a two-way communication pathway between the gut and the brain, where the health/state of one affects the health and function of the other.
A major player in this communication network is the vagus nerve.
What Is The Vagus Nerve?
The vagus nerve is the main nerve of our parasympathetic nervous system. Picture it as our inner nerve center.
The word vagus is Latin for “wandering,” and that’s exactly what this nerve does. It is the longest nerve of the autonomic nervous system in the human body, running from our brain stem to our colon, and it is of crucial importance in modulating both our sensory and motor systems.
That is because it consists of sensory and motor pathways. The former consist of the somatic, the sensations we experience in our muscles and skin, and the visceral, the sensations arising from the organs within our body.
The motor pathways stimulate a multitude of muscles, such as our heart, our mouth, and throat, and the involuntary movements which aid food moving in the digestive tract.
If you picture the information moving in the body as a network, about 80% of it moves up from the body to the brain, and only about 20% of the traffic moves from the brain to the body. That is a lot of traffic, and the vagus nerve handles the majority of it!
Carrying Crucial Information
The vagus nerve communicates information to the brain from vital organs, such as the liver, heart, and lungs. The messages are critical to the everyday functions of the body, such as increasing and decreasing heart rate, stimulating the production of bile and digestive enzymes, and triggering the release of hormones that regulate moods, like oxytocin and serotonin. 
These hormones are of primary importance in mood regulation and feelings of wellbeing. We are therefore increasingly aware that the vagus nerve and the gut can play a significant role in mood disorders. 
The vagus nerve is also involved in the process of retaining memories. In a study published in the Journal of Translational Medicine, scientists found rats’ ability to retain spatial and fear-based memories (created to protect them from previous negative outcomes) was strengthened with the electrical stimulation of their vagus nerve.
There is a myriad of muscle movements that facilitate the functions within our body, and the messages triggering them originate from our brain and travel down the vagus nerve.
Peristalsis is the movement within our digestive tract that pushes consumed food to our colon. Any inhibition of peristalsis can result in slower transit time and constipation.
The vagal efferents (messages from our brain to our gut that travel along the vagus nerve), together with hormones such as peptide cholecystokinin, ghrelin, and leptin determine the rate of absorption, storage, and utilization of nutrients. It is therefore a crucial regulator of appetite and also how much of the healthy food we eat actually benefits us.
The vagus nerve modulates the immune response and sends anti-inflammatory signals to other parts of the body through three pathways:
1. Hypothalamic-Pituitary-Adrenal Axis (HPA Axis): The interaction between the hypothalamus, pituitary gland, and adrenal glands is referred to as the hypothalamic-pituitary-adrenal axis or HPA axis. It determines the body’s response to stress and is the reason we produce the stress hormone, cortisol.
Regulating it can lower the post-stress amounts of cortisol.
2. Vago-Splenic Pathway: In this case, the vagus nerve stimulates the splenic sympathetic nerve which in turn stimulates the release of noradrenaline and Acetylcholine.
3. Cholinergic Anti-Inflammatory Pathway: This one is mediated through the vagal afferent fibers which carry messages to the brain and prompt the release of acetylcholine to inhibit inflammatory molecules.
WOW! And that’s really not everything.
But now, knowing all that…
Is Your Vagus Nerve Damaged?
Find out how to tell and what to do about it in our friend Sarah Otto’s wonderful publication…
With this brand-new ebook from health researchers Sarah Otto and Matt Potts (creators of ‘The Gut Solution’, ‘The Gut-Immune Solution’, and ‘The Inflammation Solution’), you’ll discover:
- Why you need your vagus nerve to be in top form (+plus your body functions that will be affected when it’s damaged)
- Signs and symptoms of a damaged vagus nerve (watch out for these!)
- 7 powerful and all-natural ways you can stimulate your vagus nerve at home (without any fancy equipment or tech)