The vagus nerve, also called 10th cranial nerve, is the longest and most complex of the cranial nerves, and one of the most important nerves in your body.
Let me explain why. The word "vagus" actually means "wandering" in Latin—and that's exactly what the vagus nerve does. It has an average of 100,000 parasympathetic nerve fibres that connect your brain with almost every organ in your body.
The vagus nerve is the primary component of your parasympathetic nervous system (rest and digest, or feed and breed response), and as a consequence plays a key role in your heart rate, breathing rate, digestion, detoxification and much more.
The key thing to remember is that only one part of your autonomic nervous system can be activated at any one time. When your body is in stress mode (the sympathetic, fight or flight response), and for many people this is most of the time, it’s unable to carry out those crucial daily tasks like digesting, detoxing, healing.. for you to be healthy and function well.
To perform these crucial tasks your parasympathetic (rest and digest state) must be activated.
Vagal tone reflects the level of parasympathetic activity and your body’s ability to successfully respond to stress, adverse life events, and environmental conditions.
Higher vagal tone is linked to an increased resilience to stress, reduced allostatic load (the amount of stress you accumulate over time), less anxiety, and healthier emotional, physical and mental well-being.
The gut-brain axis and vagus nerve
The enteric nervous system (ENS), which governs the function of the gastrointestinal tract, communicates with the central nervous system (the brain) via the vagus nerve. This is known as the gut-brain axis and is like a highway with a two-way signaling channel, where the vagus nerve sends messages in both directions.
Eighty percent of the information transmitted via the vagus nerve travels from the body to the brain, and twenty percent from the brain to the body. Surprising, isn't it, when you discover that your stomach has more to say for itself than your brain, so to speak.
One of the most interesting roles of the vagus nerve is that it activates the gut microbiome. This activation initiates a response to modulate inflammation and effects on your brain and behaviour, based on whether or not it detects pathogenic vs non-pathogenic organisms and the overall health of your microbiome population.
Poor vagus nerve function explains why stress impacts our gut health so much. When you have strong vagal tone you are much more likely to:
- produce gastric juices, stomach acid and digestive enzymes
- have good peristalsis (wave-like muscle movement) throughout your GI tract
- benefit from a thriving microbiome community in your gut
- experience regulation of intestinal permeability by tight junctions to prevent inflammatory responses
- enjoy optimal nutrient uptake
Measuring Vagal Tone
One of the best ways to measure your vagal tone is by tracking your heart rate variability (HRV). This is the time between each beat per minute and how much variation and time. Obviously, this changes over time but the higher the HRV the better the vagus nerve is functioning. High vagal tone correlates with high HRV and means, as I've already mentioned good adaptability to stress.
8 Ways To Improve Vagal Tone
Now you know more about the vagus nerve and why it's so important to your health, what can you do to improve vagal tone?
1. Incorporate aerobic exercise into your week
Incorporating and challenging your cardiovascular activity within your limits, is a great way to improve your HRV and vagal tone. Physiological changes in your muscles and bones can happen immediately with aerobic activity.
While walking in nature can be wonderfully calming, you need to be getting out of breath to improve your adaptability to stress and strengthen your vagal nerve function.
If you struggle to exercise due to fatigue, start with just 2 or 3 minutes a day. Wait 24 hours and if you’re ok (in terms of muscle aches, energy etc…) do the same the following day, and then build it up gradually week by week.
It’s really important to incorporate some intensity into your activity. Essentially, this is high intensity interval training (HIIT). For example, walk for a couple of minutes, then run for one minute. The key is to find your cardio activity sweet spot. If you overdo the length and intensity of your session, you’ll likely have issues with electrolyte imbalance and muscle strain.
To give you an example of how good cardio is for strengthening vagal tone and healing – I worked with a professional footballer who was struggling with an injury for 4 months. Usual recovery time from the injury he suffered is about 12 months. From an exercise perspective he stretched and did strengthening work, neither of which really had any impact on speed of recovery, but when he returned to cardio training his injury healed almost instantly. Even though stretching and strengthening are important components of any rehab programme, I can't help but think that his speedy recovery had something to do with the aerobic activity increasing vagal tone. Of course it's crucial to also work within your physical capacity.
2. Improve your posture and correct muscle imbalance
Even something as simple as bad posture can negatively impact the vagus nerve. Poor posture along with muscle imbalances (when two or more muscles in the body that oppose each other are disproportionate) can also cause the vagus nerve to misfire.
Posture while eating affects how the enteric nervous system digests food. Slouching can cause peristaltic waves to be irregular and may even lock food in one place of the digestive system, causing irritation.
Something else, stooped forward posture displaces and compresses thoracic and abdominal organs – such as the heart, lungs, stomach and diaphragm. It also compresses the nerves that run between spinal segments which can include irritation of the vagus nerve.
The vagus nerve is responsible for the normal contractions of the upper and lower esophageal sphincters. If everything is operating well the sphincter will open to allow food to pass from the esophagus (the “food tube” connecting the mouth to the stomach) into the stomach and then closes to prevent backflow of food and stomach acid back up the esophagus.
When the vagus nerve is compressed and irritated, the sphincters do not operate correctly and instead, remain partially open. This allows the reflux of stomach acid, which is responsible for symptoms like heart burn.
Any improvements you can make to your posture to include keeping your muscles balanced and free from tension will help to prevent irritation of the vagus nerve and any subsequent health impact. Things like yoga, massage, and making sure you're ergonomically set up correctly at your computer, will all help to increase vagal tone.
3. Eliminate excess sugar from your diet
We don’t tend to associate sugar with the nervous system, but over consumption of sugar is one of the worst things for it. Research shows that the vagus nerve relays signals from the periphery of our body to our brain to help regulate glucose. This connection with glucose metabolism explains why vagus nerve stimulation reduces insulin resistance.
Problems with insulin resistance can suppress part of the vagus nerve in the liver, dysregulate the digestive tract and contribute to parasitic activity, as well as reducing defence against bad bacteria in the GI tract. This in its own way places stress on the body and contributes to chronic inflammatory processes.
If the vagus nerve is strong and works well it can dampen that stress and inflammation, but if it’s weak that will not happen.
Clearly, if you don’t want to have inflammation associated with excess sugar the obvious thing to do is to reduce your sugar intake. But when the body has already been damaged reducing sugar intake alone is not enough, so strengthening your vagus nerve too will help you considerably to improving your metabolism.
Remember it’s not actually the sugar that’s a problem, it’s the excess sugar. The amount of sugar you can get away with depends on how well you self-regulate sugar. And this includes simple carbohydrates like pasta, rice and bread.
4. Avoid eating foods that don't agree with you
Food sensitivities or intolerances may be taking your autonomic nervous system out of balance.
Knowing what foods upset your gut like gluten, caffeine or dairy, and avoiding them will help to keep you in that parasympathetic state with good vagus nerve function.
When you eat something that doesn’t agree with you it automatically raises those "fight or flight" sympathetic state alarm bells. And stomach pains aren’t the only sign that something has triggered an immune system response within your body, and it's making antibodies to fight the intruder.
5. Prioritise deep restorative sleep
One of the best ways to tune up your body is through sleep. Deep restorative sleep is like the gym for your vagus nerve.
If you don’t sleep well your vagal nerve tone deteriorates faster. Your digestion, breathing and hormones don’t work so well when you’ve lost the connection with your circadian rhythm - the cyclical 24-hour period of human biological activity.
Studies show that sleeping on your right side increases your HRV. Experiment - see what you notice when you change your sleeping position and how it affects your breathing.
6. Feel & process your emotions effectively
Eighty percent of vagus nerve input is sensory and comes from the gut, heart, lungs, and information you allow in from the external world. So a gut feeling is a very real experience.
And what doesn’t get emotionalised gets physicalised. When you disconnect from your body's emotional signals you go into survival mode (e.g. defending and protecting) which throws you into the sympathetic, "fight and flight" state, shutting down digestion, immunity and spiking blood sugar to name but a few.
To prevent flicking the “stress state” switch on in your body, pause for a moment and connect with what’s going on at the time. Experience the whole range of what you feel mostly through body sensation, as this is what makes us know the feeling.
You should be able to feel the emotion flowing through you. For example, heat in your chest and upward when you’re embarrassed or angry.
Always connect with the feeling you’re aware of at the time, rather than ignoring it or settling with the “avoidance” feeling, that is likely your default for being at ease with specific emotional triggers. If you opt for the latter, you won’t be feeling and processing the emotion.
I totally get it, that this isn’t easy. But it is a big deal. For the sake of your health and wellbeing you really want to be able to process emotion effectively.
A couple of mind-body health practices that I use with clients to help them overcome negative self-talk and beliefs, and effect behavioural change (which is so often the thorn in the rose that’s holding them back from getting the health results they really want), are Emotional Freedom Technique (EFT) and Matrix Reimprinting.
These practices help to balance the autonomic nervous system by affecting the energetic flow of information in the body, so you can correctly judge and connect with what’s going on in your environment.
Not only do they reduce cortisol levels rapidly, but they also help you to process emotion effectively and change behavioural responses. Because unprocessed emotion from past events in life can hold you back from optimal health and wellness. Even though you know what you need to do that in itself doesn’t always bring success.
7. Experiment with cold therapy
When done on a consistent basis, studies show that cold therapy can activate the vagus nerve, as well as various neurons on the vagus nerve pathway, causing a shift to parasympathetic nervous system activity.
Cold therapy ideas:
- Submerge your body up to your shoulders in cold water, like cold-water sea, a cold-water swimming pool or a cold-water bath.
- Splash cold water on your face.
- Apply a cold washcloth to the face.
- End your shower with 60 seconds of cold water.
8. Engage in breathing exercises daily
Slow rhythmic breathing exercises especially nose breathing with longer exhales. Alternate nostril breathing, and diaphragmatic belly breathing with a deep inhale and a long, slow exhale will stimulate the vagus nerve, slow heart rate, reduce blood pressure and stress hormones.
Do you have any vagus nerve experiences that you'd like to share? If so, I'd love to hear about them, so please do share in the comments below.
If you'd like help to reach your health goals or with an ongoing health condition, you may want to check out my functional health clinic. It's my mission to help you get to the root cause of what's preventing you from optimising your health and wellness.
Hi, I'm an Integrative Nutrition Health Coach, Pain & Stress Management Therapist, and Certified Functional Medicine Practitioner.
I help people elevate their mind and body health by addressing diet, nutrition and lifestyle symptoms. Let's work together to optimize how you feel and function.
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