Credits and thanks to Jordon Rosenfield and Tina Gammon
9 Fascinating facts about the Vagus Nerve.
The vagus nerve is so named because it “wanders” like a vagabond, sending out sensory fibres from your brain stem to your gut. It's the longest of the cranial nerves, controls your inner nerve centre—the parasympathetic nervous system. And it oversees a vast range of crucial functions, communicating motor and sensory impulses to every organ in your body. Recent research has revealed that it may also be the missing link to treating chronic inflammation, and the beginning of an exciting new field of treatment for serious, incurable diseases. Here are nine facts about this powerful nerve bundle.
1. The vagus nerve prevents inflammation.
A certain amount of inflammation after injury or illness is normal. But an overabundance is linked to many diseases and conditions, from sepsis to the autoimmune condition rheumatoid arthritis. The vagus nerve operates a vast network of fibres stationed like watch dogs around all your organs. When it gets a signal for beginning of some inflammation—the presence of cytokines or a substance called tumour necrosis factor (TNF)—it alerts the brain and draws out anti-inflammatory neurotransmitters that regulate the body’s immune response.
2. The vagus nerve helps you make memories.
A University of Virginia study in rats showed that stimulating their vagus nerves strengthened their memory. The action released the neurotransmitter norepinephrine into the amygdala, which consolidated memories. Related studies were done in humans, suggesting promising treatments for conditions like Alzheimer’s disease.
3. The vagus nerve helps you breathe.
The neurotransmitter acetylcholine, elicited by the vagus nerve, tells your lungs to breathe. It’s one of the reasons that Botox—often used cosmetically—can be potentially dangerous, because it interrupts your acetylcholine production. You can, however, also stimulate your vagus nerve by doing abdominal breathing or holding your breath for four to eight counts.
4. The vagus nerve controls your heart rate.
The vagus nerve is responsible for controlling the heart rate via electrical impulses to specialised muscle tissue—the heart’s natural pacemaker—in the right atrium, where acetylcholine release slows the pulse. By measuring the time between your individual heart beats, and then plotting this on a chart over time, doctors can determine your heart rate variability, or HRV. This data can offer clues about the resilience of your heart and vagus nerve.
5. The vagus nerve initiates relaxation after stress.
When your ever-vigilant sympathetic nervous system revs up the fight or flight responses—pouring the stress hormone cortisol and adrenaline into your body—the vagus nerve tells your body to chill out by releasing acetylcholine. The vagus nerve’s tendrils extend to many organs, acting like fibre-optic cables that send instructions to release enzymes and proteins like prolactin, vasopressin, and oxytocin, which calm you down. People with a stronger vagus response may be more likely to recover more quickly after stress, injury, or illness.
6. The vagus nerve lets your gut "talk" to your brain.
Your gut uses the vagus nerve like a walkie-talkie to tell your brain how you’re feeling via electric impulses called “action potentials." Your gut feelings are very real.
7. Overstimulation of the vagus nerve is the most common cause of fainting.
If you tremble or get queasy at the sight of blood or while getting a flu shot, you’re not weak. You’re experiencing “vagal syncope.” Your body, responding to stress, overstimulates the vagus nerve, causing your blood pressure and heart rate to drop. During extreme syncope, blood flow is restricted to your brain, and you lose consciousness. But most of the time you just have to sit or lie down for the symptoms to subside.
8. Electrical stimulation of the vagus nerve reduces inflammation and might stop it altogether.
Neurosurgeon Kevin Tracey was the first to show that stimulating the vagus nerve can significantly reduce inflammation. Results on rats were so successful, he reproduced the experiment in humans with stunning results. The creation of implants to stimulate the vagus nerve via electronic implants showed a drastic reduction, and even remission, in rheumatoid arthritis (which has no known cure and is often treated with the toxic drugs), hemorrhagic shock, and other equally serious inflammatory syndromes.
9. Vagus nerve stimulation has created a new field of medicine.
A burgeoning field of medical study, known as bioelectronics, may be the future of medicine. Using implants that deliver electric impulses to various body parts, including the vagus nerve, scientists and doctors hope to treat illness with fewer medications and fewer side effects.
The vagus nerve could be likened to the queen of the parasympathetic nervous system — a.k.a. the “rest and digest” — so the more we can do things that “stimulate” or activate it, like deep breathing, the more we offset the effects of the sympathetic nervous system and reduce cortisol levels. Ideally, within your autonomic nervous system, the tug of war between these two opposing mechanisms creates a "yin-yang" type of harmony marked by homeostatic balance.
Unfortunately, the hectic paced, digital age we find ourselves living in causes our evolutionary biology to short-circuit by throwing our individual and collective nervous systems out of balance. It's for this reason that a healthy vagal tone has become a heightened area of research within the scientific community. Thankfully, there are easy to implement, highly effective, science-backed ways to activate the power of your parasympathetic nervous system by stimulating your vagus nerve.
7 EASY WAYS TO STIMULATE YOUR VAGUS NERVE
According to one study, when the body is exposed to cold therapy, our fight-or-flight system declines and our rest-and-digest system increases - stimulating the vagus nerve. An easy way to get started? Cold showers. Learn more of the benefits associated with cold therapy here and check out our three favourite ways to get started with cold therapy here.
In a study of 65 people, half of the participants were instructed to sit and focus their thoughts on positive thoughts towards others. The result? Increased positive emotions produced increases in vagal tone, an effect mediated by increased perceptions of social connections.
Meditation has amazing neurological benefits - from altering grey matter volume, to stress reduction, improved focus, and increasing creativity but it’s also a powerful neurohack to support vagal tone.
In a 2016 study, 35 test subjects practised mindfulness meditation as a means to handle life’s stressors. After four months, subjects showed higher levels of brain connectivity and lowered inflammation, indicating a healthier vagal tone.
If you love the science behind breathwork as much as we do, you will love our podcast interview with Ariel Garten of Muse, creators of the brain-sensing headband biohackers love for deeper meditation practices.
Breathwork is one of the fastest and easiest ways to activate the vagus nerve. By applying strategic breathing practices, you are able to utilise the body and mind to experience pure consciousness also known as a sense of oneness. Check the research, here, and learn more about our favorite breathwork technique, here. You might even love this podcast interview with Dr. Andrew Huberman, as he helps us better understand how to use breath to shift out of fear states.
Laughter stimulates diaphragmatic breathing, activates the parasympathetic nervous system, and triggers the “tend-and-befriend” response linked to healthy vagal tone. Even ten minutes of laughter is sufficient in triggering mental and physical health benefits. Take a peek at the research.
SINGING AND CHANTING
The vagus nerve is connected to both your vocal cords and the muscles at the back of your throat. Singing, chanting, and even humming have been shown to activate these muscles and increase heart rate variability, thus stimulating your vagus nerve.
We know that exercise supports mitochondrial health and helps reverse cognitive decline, but it’s also been shown to stimulate the vagus nerve, which may explain its beneficial brain and mental health effects. Read the study, here.
By understanding the incredible power of your vagus nerve you can begin practising ways to flex its inhibitory strength to help you live an optimised life and offset the effects of the sy
mpathetic nervous system.
Credits to Jordon Rosenfield and Tina Gammon