top of page
  • Writer's pictureDavid Hurley

The Vagus Nerve - nothing vague here!!

So my Blog, each time, is about my passion, my love. How the body works, recovers, regenerates, grows, strengthens, adapts and supports you through a happy healthy life, it’s genuinely what I love and I never stop learning.

The information in each Blog is drawn from a number of sources, my learnings (from recognised blue chip education facilities and educators), research, peer reviewed research and information that has gone on to shape and drive treatment, medicine, sports science, training and sports performance. And also general practice and people’s health. In other words, strong science based fact.

I have added this introduction as over time I have had some communication that has criticised and disapproved of my writings, that’s absolutely fine, I expect that, everyone is entitled to an opinion. But that’s the thing, my writings are not opinion they are fact based information. I recognise that over time knowledge grows and changes, it’s the nature of the human condition, and sometimes we read or hear things that are so plausible and sold to us as fact, but these can be just someone’s opinion or the information has been preceded by new found knowledge.

So if there is something you don’t understand or agree with please spend a little time just investigating from true recognised sources, or contact me directly, happy to discuss, debate and more importantly listen. Having comments and contact from everyone is a pleasure and a privilege.

So following on from the last article, here we go with the Vagus nerve, if you didn’t think the body was clever and special before ……… you will now.

The Vagus nerve is the 10th cranial nerve that basically leaves the skull and is routed through an area right around the region of the neck and involves something called the Nodose Ganglion. Then it goes down through our abdomen and extensively innervates (supplies an area with nerves) the organs of the body. The heart, the lungs, the liver, the viscera. Even some of the musculature around them is influenced by the Vagus nerve. So basically connects to all the major organs of the body.

There are also Vagal nerve pathways that go back from those organs up to the brainstem and can influence higher brain centres. Now that means that the Vagus nerve, despite its name suggesting it's a nerve, would be like a single fibre bundle of axons with wires that come from neurons, it is actually a superhighway. And it's a very divergent and convergent superhighway of nerve pathways. In fact, the word "Vagus" means essentially "vagabond" or "to wander." In essence a two way communicator to and from the brain that goes all over the mid body section.

Just recently it has become popular and fashionable, in pop psychology and popular wellness circles, that the Vagus nerve can be manipulated and used through meditation and other various techniques to control the body. So much so that it's generally believed that the Vagus nerve is responsible for calming the body and the brain down, the reality is, that this is just not true and in some respects stimulating the Vagus nerve could be down right dangerous.

So we have running from our brain, down through our neck and into our abdomen, then branching out all over the place, this massive bundle of nerves and neurons that sends signals and hormones down through the body to control all of our internal functions, digestion, chemicals used in the liver and pancreas, heart function, breathing, cholesterol production, sexual function, the list goes on and on. But it doesn’t stop there, because as well as this top down communication, signals are sent back to the brain to control and make more hormones, change activity and function in other parts of our body and keep us as balanced as we can be, the Vagus nerve is even responsible for the feeling of butterflies in the stomach, and if the truth be known, we and scientists really don’t know the full extent of Vagus nerve activity within us and massive amounts of research are constantly being carried out on this one aspect of our bodies.

So a true wonderous function inside every single one of us.

And to demonstrate how wonderous this all really is, here is a living example of just one of millions of activities inside us that the Vagus nerve controls.


The Vagus nerve is so fascinating, I can’t stop saying this, because it truly is one of the wonders of our body, it's this super highway in you, in me and it has oh-so-many interesting effects. So I just want to tell you about one effect that is very relevant for everybody, which is, as you recall earlier, the Vagus nerve doesn't just consists of nerve pathways from the brainstem out to the organs of the body, but also back from the organs to the brain itself.

And there is a specific Vagal nerve pathway that goes from the lining of the gut up to regions in the brain that then send on messages to yet further regions that stimulate the release of Dopamine, which is a molecule associated with motivation and seeking. More often than not, the seeking out of things that are pleasurable or at least that, in the short-term, are pleasurable. Sugar, sex, temperature, exercise, financial rewards, relationships and so on and so forth. Just an aside here, most folk think of Dopamine as the hormone of pleasure, sorry to say it’s not. It’s the hormone of motivation, the thing that gives us the drive, it’s also the hormone that creates addiction, this sounds like a blog for another time, and will be.

The Vagal nerve pathway that starts within the gut and then communicates with the dopamine system is sensing mainly three things. Essential fatty acids, so this would be your omega-3s, your omega-6s. Amino acids, in particular, the essential amino acids that come from high-quality protein foods. And sugar.

There are neurons in your gut that are activated, that is to say, they send electrical impulses up through the Vagus nerve to the brain to then stimulate the release of dopamine when you ingest things that contain sugar, amino acids, and in particular, essential amino acids from high-quality proteins, and essential fatty acids.

Why would this pathway exist? Well scientists believe that this pathway exists in order to get us to be motivated, to seek out more of particular foods that bring sugar, essential amino acids, and essential fatty acids because those three things are not just highly rewarding, but they are critical for our survival, perhaps much more so than other things out there because we need essential amino acids for muscular and tissue repair.

We need essential fatty acids for nerve cell and other cellular repair. Those essential fatty acids are actually brought into and become the building blocks of the cellular membranes of everything, from neurons to other cells in the body, but in particular, neurons.

And then of course, sugar, sugar is highly rewarding and enticing, we know that. Even if you're somebody who doesn't like really sweet stuff, I don't know anybody that, at least at some stage of their life, didn't like a really delicious piece of chocolate or a really delicious piece of cake at some point in their life, maybe even before they wean themselves off sugar.

Well, these neurons in the gut are essentially sitting there, waiting to trigger the yearning for sugar, the need for a sweet very quick hit of energy / fuel, instant fuel that can be easily used within the body. It’s quite common to think that that yearning comes from the taste of sugar, but that would be wrong, it comes from the neurons attached to the Vagus nerve in your gut.

Yes, the taste of sugar; yes, the taste of savory meat; yes, essential fatty acids will trigger an appetite of the sort that we're used to thinking about, the kind of mental and emotional appetite for certain foods. But at the level of your gut, the neurons of the Vagus are sending signals up to the brain and getting you to actually seek out and consume more of those foods because your body can use those foods and really needs those foods.

Now do you need more of them? Not necessarily. That's where the taste of these foods becomes confounded with our absolute need for them. We tend to over-consume sugars. Most people won’t over-consume essential amino acids from healthy sources, or savoury foods, but they will definitely over consume sugars.

What the issue becomes is when people are consuming a lot of sugar and these neurons in the gut are getting activated, and then we're seeking out more sugar, it becomes a vicious circle and then through the over consumption of sugar the signal to eat gets turned off, we’re then not getting enough of the “good” nutrients and then eventually we then crave more sugar because it provides “quick cheap” fuel / energy. This then has the result that we're not getting enough of the foods with the essential amino acids, such as high-quality proteins or high-quality fatty acids. This circle keeps going and going and going and is one of the main causes of weight gain, obesity and diabetes.

If you think this is bad, wait for the next bit. These neurons in the gut are also responsible for telling our brain when we are full and when we need to eat, in other words they regulate our hunger and when we should and shouldn’t eat, they tell us to stop if we are full. If the above cycle continues the neurons in the gut run the risk of being permanently damaged by the over exposure to sugar and so to protect themselves they go into hibernation. They bury themselves in the lining of the gut where the sugar can’t degrade them and then, guess what?, the bodies ability to regulate food intake gets turned off and there is almost a constant need to eat, and the second guess what is?, it will be mostly sugar rich foods which just cause the whole process to continue and speed up.


One thing that I know by my own experience and the experience of many other people is that the above is very dangerous and causes excessive weight gain. But one way to counter this craving for sugars is to simply increase the amount of quality protein containing essential amino acids that you consume and to increase the amount of essential fatty acids like omega 3s in the form of fish oil that you consume, or other forms of omega 3’s. Because then those neurons will essentially come out of hibernation, work correctly, send signals to the brain to get you to eat more proteins, tell you when you are full and it becomes a positive upward spiral, not the negative destructive downward pattern.

In other words, you can do, a silent substitution, as it’s called in physiology. You can, in an unconscious way, substitute the thing that activates those very same neurons so that you're seeking out the things that are actually healthy for you. And while I'm not someone to demonize sugar, I do believe that most people would do well to eat less sugar, less highly processed foods, and more high-quality proteins and more high-quality essential fatty acids, maybe things like fish, providing the omega’s.

So you can pick your protein sources according to whether or not you're vegan, vegetarian, or omnivore such as me. I'm an omnivore, a proud omnivore, and in that way, control your appetite, get the nutrients you need, control your weigh and have more energy. And yes, it's all being done via the Vagus, simply brilliant.

1 view0 comments

Recent Posts

See All

Hormones - The chemical soup inside you!

So a bit of a divergence again, a delve into our bodies and what keep us alive, hormones the chemicals that drive every process, action, reaction and activity within our bodies. But these are nothing

Resistance Training. The smart way to train!

Resistance Training Regular resistance training can improve your strength and flexibility and if you could do just one thing to improve your health, resistance training should be at the top of your li

Resistance Starch - A True Super Food

Many people have added resistant starches to their diets due to the health benefits they may provide. Resistant starch is a type of nutrient that may help your body with digestion, weight loss, diseas


bottom of page