Introduction to the Vagus Nerve
The vagus nerve is a significant component of the parasympathetic nervous system and plays many roles in the body. It is increasingly recognized as an essential driver of gut-brain axis communication, which may be involved in the pathogenesis of several disorders. This article reviews how this ” long and wandering” nerve works and how its activity can affect health. And yes, I’ll get to the discussion about vagus nerve stimulators after I get through the “why.”
I’ll cover everything from vagus nerve symptoms (from insufficient activity) to discussing how to augment vagal tone to going into actual vagus nerve stimulation. Can’t wait? Do you know why you need VNS but don’t know which device works best? It’s this one. And you can get a nice discount using my code (feel free!): DrKim25. And yes, as you’ll learn, this is the best vagus nerve stimulator currently available without surgery and/or a prescription. First, let me cover the following topics.
- Basic anatomy and function of the vagus nerve
- The Autonomic nervous system
- Specific roles of the vagus nerve in our bodies
- Heart rate variability
- Immune and inflammatory mediation
- The gut-brain-microbiome connection via the vagus
- The vagal connection to chronic diseases
- Oxidative stress, inflammation, sympathetic overdrive, and the vagus nerve
- Methods of improving your vagal tone
- What you came for: VNS without the work: using a vagus nerve stimulator
The Basic Anatomy and Function of the Vagus Nerve
The vagus nerve, also known as cranial nerve X (10), is the largest nerve in your body. It runs from your brain stem through your neck, chest, and abdomen. The nerve is nicknamed “the Wanderer” (Latin for vagus) because it wanders so far through different organs.
The vagus is a bundle of nerves connecting the brain to several vital organs, including the heart and stomach. It helps regulate several bodily functions and brings stress under control. When its tone (or activity level) is dampened, it impacts vast activities in your body that lead to a decline in health. Supporting and protecting this great “Wanderer” is vital for optimal health. I’ll get into how to do that later in this article.
The vagus nerve is a nerve that maintains homeostasis of the neuro-endocrine-immune systems and controls the parasympathetic (rest, relax, repair) autonomic nervous system. The following section will cover more specifics of the entire autonomic nervous system.
The vagus nerve originates in your brainstem as a pair of nerves, one traveling down the left side of your neck and the other down the right. It then travels down into the trunk of your body, where it innervates (stimulates) your throat and esophagus (the tube that carries food from your mouth to your stomach).
It then wanders downward to innervate your heart (the organ that pumps blood throughout the body), lungs (organs that extract oxygen from the air), liver (the inner organ that removes toxins from the blood), and spleen (the organ that produces immune cells).
Next, it stimulates your pancreas (the organ that produces insulin), stomach (holding chamber for food), gallbladder (small organ next to the liver that stores bile), urinary bladder (vessel holding urine before disposal) and kidneys (the inner organ that filters excess water from blood).
Its last stop is in your small intestine (the tube connecting the stomach to the large intestine) and the first part of the colon (the large intestinal tube storing waste before disposal).
This master nerve is a two-way communication system that relays information from your brain to your internal organs and back again. This nerve accounts for about 80 percent of the fibers that carry information upward to the brain and 20 percent of those that carry information downward from the brain to your internal organs.
The vagus nerve helps control heartbeat, heart rate, and respiration. It affects blood pressure by modulating vasodilation. It is a vital part of the parasympathetic nervous system (PSNS) and other nerves that support “rest-and-digest” activities such as digestion, sexual arousal, and reproduction. It helps balance against sympathetic (fight, flight, stress) nervous system tone.
Consequently, it buffers against stress-related hormones and inflammatory compounds. Now, I’d like to give you a general idea of the autonomic nervous system.
How Does the Autonomic Nervous System Work?
To understand the workings of the vagus nerve, it is first essential to know how the entire autonomic nervous system works. The ANS is comprised of two sides that usually work in opposition. (We are not including the recently described enteric system in this article).
These two sides are the sympathetic and the parasympathetic arms. The autonomic features of the stress response are mediated by the sympathetic arm, which is sometimes called the fight, flight, or freeze response due to the bodily changes needed to enable you to defend yourself physically, run away from danger, or even freeze in total panic.
The other arm of the ANS, the parasympathetic, is the rest, digest, relax, and restore mode. If that sounds more fun, it is in the sense that it’s what is dominant when relaxing on a couch, meditating in your favorite chair, or socializing with friends.
In this state, your body slows down, heals, and returns to homeostasis. Your organs, including your brain, stick to their maintenance schedules, and everything feels fine.
It is often helpful to think of the sympathetic and parasympathetic nervous systems as gears in a car. The sympathetic gear is responsible for speeding up a car when it is in danger or when the driver wants to overtake, but it also leads to wear and tear over time if used too much. The parasympathetic gear keeps the car running smoothly by slowing down when necessary and stopping other parts from overworking themselves.
In response to danger, the sympathetic arm of the autonomic nervous system activates the body’s inflammatory response–a process that usually causes immune cells to produce cytokines and other chemicals that trigger inflammation. Clinical studies have shown that stress and other stimuli can cause flare-ups in autoimmune diseases, accelerate neurodegenerative disorders, exacerbate atherosclerotic plaque formation, worsen asthma symptoms, and even lead to cancer recurrences.
The many roles of the Vagus Nerve
The vagus nerve stimulates organs throughout the body. Scientific research has focused on its connection to the gut, brain, and immune system–areas where vagus nerve stimulation has been shown to provide benefits. We’ll discuss those three areas in detail, but first, let’s look at some other systems that can be affected by low vagus nerve activity, which produces what some people call vagus nerve symptoms.
Mouth and Ears
The vagus nerve helps control taste and saliva in the tongue, tears in the eyes, and hearing in the ear. Scientists are studying whether ear stimulation can activate the vagus nerve while affecting tinnitus. Thus far, auricular vagal stimulators are considerably less effective than externally applied stimulating devices.
Kidney and Bladder
Some research suggests that the vagus nerve promotes general kidney function by helping to control blood glucose and increasing blood flow, which improves blood filtration. Vagus activation likely also releases dopamine in the kidneys, which helps excrete sodium and, therefore, lower blood pressure. However, the mechanism is not fully clear in humans; more studies are needed.
The vagus nerve innervates the bladder. A potential side effect of its stimulation is urinary retention. On the other hand, less vagus stimulation may make people urinate more frequently.
Although there are no good clinical studies on this topic, some practitioners hypothesize that their patients who complain about frequent urination may have a vagus nerve issue in combination with other factors such as low vasopressin (ADH) and low aldosterone as well as high cortisol.
In the spleen, vagal activation can reduce inflammation. It is thought that vagal activation may affect various organs by releasing acetylcholine. However, when it activates in the spleen, its response is believed to be via reduced inflammatory cytokine production.
Liver, Pancreas, and Gallbladder
Glucagon is a pancreatic hormone released via vagal stimulation that acts as a counter-regulatory hormone to insulin. It opposes insulin by stimulating the breakdown of glycogen and triglycerides.
Glucagon also stimulates the release of bile from the gallbladder, which helps break down fat and absorb fat-soluble vitamins.
Female Reproductive Organs
The vagus nerve may affect a woman’s fertility and orgasms by connecting to the cervix, uterus, and vagina. However, since most of what we know about the effects of the vagus nerve on women comes from animal studies, many questions about its impact on male and female reproductive human health remain unanswered.
In the heart, it controls blood pressure, and something you may have heard about as an app-driven buzzword: heart rate variability. Recent studies reveal that an overactive sympathetic nervous system will lessen heart rate variability (HRV).
HRV and Sympathetic Overdrive
Most studies have found that heart rate variability (HRV) is affected by stressful situations. Low parasympathetic activity, a decrease in the vagus nerve activity, has been reported as a factor related to changes in HRV variables. Neuroimaging studies suggest that HRV may be linked to brain regions that evaluate or appraise stressful situations (e.g., the ventromedial prefrontal cortex).
The current neurobiological evidence suggests that stress impacts heart rate variability and supports its use for objectively assessing psychological health and so-called “stress levels.”
Heart rate variability can be measured using an app. This provides insight into the connection between vagal nerve tone and heart rhythm. The bottom line: high levels of heart rate variability are associated with good health and low levels are linked with poorer health.
Some people call these vagus nerve symptoms, even though the symptoms are due to a reduction in vagal activity. Next, let’s revisit some areas where high vagal tone and high HRV are beneficial.
Epidemiological evidence indicates inverse associations between vagal nerve activity, HRV, and metabolic syndrome.
High HRV is associated with a reduced risk of overall mortality and reduced risk of cancer death.
A meta-analysis of 21 studies found that myocardial infarction patients with low HRV had approximately four times the mortality risk compared to those with high HRV.
A 2012 meta-analysis of studies on high heart rate variability (HRV) and survival in cancer patients revealed a statistically significant association between HRV and more prolonged survival, particularly in pancreatic cancer patients. A separate study found that the association was mediated by reduced inflammation.
Low HRV is also associated with complications in COPD.
HRV is inversely related to insulin resistance and HbA1C levels, indicating diabetes severity and potential complications.
Its ease of measurement and independent prognostic role suggest that health policymakers should consider routinely implementing this biomarker to predict and prevent major diseases. More on this is coming, but first, let’s turn to the next important area where the research has borne out the benefits of increased vagal tone.
Immune System Function and Inflammation Management
The vagus nerve directs immune activity, suppressing pro-inflammatory cytokines (chemical messengers) produced by immune cells in the spleen. This helps manage inflammation from the respiratory tract and throughout the body’s immune system. We’ll get deeper into the inflammation part later in this article.
The following section will discuss a different mechanism for reducing inflammation by stimulating the gut. Regular vagal nerve activity dampens pain signals in the brain and spine and reduces pain-related behavior. We will expand on this concept later when we discuss vagus nerve stimulation.
Gut-brain-microbiome communication via the vagus nerve
The brain, gut, and microbiota communicate through the microbiota-gut-brain axis in a bidirectional way that involves the autonomic nervous system. The vagus nerve (V.N.), which transmits information from the brain to many organs, is a mixed nerve composed of 80% afferent and 20% efferent fibers.
The V.N., because of its role in interoceptive awareness, can sense the microbiota metabolites through its afferents and transfer this information to the central nervous system, where it is integrated into the leading autonomic network.
A cholinergic anti-inflammatory pathway has been described through vagal fibers, which can dampen peripheral inflammation and decrease intestinal permeability. This may very well modulate the composition of microbiota and aid in healing “leaky gut.”
In contrast, stress (and its accompanying high cortisol) inhibits the vagus nerve, which can harm the gastrointestinal tract and the microbiota. Stress is involved in the pathophysiology of irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD), both characterized by dysbiosis and gut hyperpermeability.
Next up: how the vagus nerve protects my favorite organ: the brain.
The Vagus-Gut-Brain Connection
The vagal nerve regulates the communication between the brain and the gut microbiome, which is affected by gut flora. The vagus nerve can distinguish between beneficial and potentially pathogenic bacteria in the gut, which modulate immune-inflammatory activity.
Research has shown that the healthy balance of gut flora and probiotics influences the brain-gut axis. A healthy gut microbiome promotes positive mood and cognitive functions via the vagus nerve cholinergic anti-inflammatory pathway. An imbalanced gut flora stresses vagal activity, which enables negative mood stress and cognitive challenges, including symptoms resembling ADHD.
Vagus Nerve Symptoms= Chronic Diseases
Symptoms and disorders listed below have been associated with vagus nerve dysfunction in various and sometimes limited studies. These are the ones worth listing and watching closely.
- IBS and IBD
- Chronic Pain
- Sleep disturbances and insomnia
- Chronic fatigue
- Cognitive impairment
- High or low heart rate (and, of course, HRV)
- Gastroparesis, also known as delayed gastric emptying
- Chronic inflammation
- Immune dysfunction
- Obesity and weight gain
- Chronic degenerative diseases associated with inflammation and oxidative stress are two of the root causes of all chronic diseases. I’ll explain the vagus connection below.
Chronic Disease and the Vagus Nerve
Unlike during the centuries that have preceded us, chronic, degenerative diseases now claim more lives than infectious diseases. Shifting our focus to addressing the root causes of these chronic diseases would save countless lives and alleviate significant suffering. Examples of this include the following:
Major non-communicable causes of death include stroke, cancer, coronary heart disease and its risk factors, and pulmonary conditions. Many risk factors (standard American diets, smoking, lack of exercise, and surprisingly, pollution!) account for many of them. Further, many of these diseases have common underlying biological causes, as shown below. The following discussions include a deep dive into inflammation, oxidative stress, and the role of the autonomic nervous system. Let’s start with oxidative stress.
Oxidative Stress and Chronic Diseases
Oxidation is a chemical reaction in which one or more electrons are added to or removed from an atom. Oxidative stress occurs when the body has more pro-oxidants than antioxidants, leading to DNA damage and diseases.
Oxidative stress is essentially the lack of sufficient antioxidant vitamins (e.g., carotenoids, active forms of vitamin E, vitamin C, and so on). So, you can think of oxidative stress as a lack of sufficient antioxidants, corrected by ingesting enough. Not to be confused with oxidative stress is psychological stress. But, yes, you guessed it, enough psychological stress can deplete antioxidants and cause oxidative stress!
Studies show a correlation between job-related psychological stress and levels of oxidative stress. Furthermore, chronic stress was related to shorter telomeres, which predict disease onset and earlier death. More specifically related to oxidative stress, higher effort-reward imbalance at work–a marker of chronic work stress–was associated with even higher levels of oxidative stress in several clinical studies.
Inflammation and Chronic Diseases
Inflammation is a complex process triggered by various danger signals, including cell damage and infection. Chronic inflammation helps cancer cells escape from apoptosis (programmed cell death) and proliferate, which can lead to metastasis.
Inflammation contributes to the development of atherosclerosis by recruiting macrophages from the bloodstream to form plaques, creating instability in atherosclerotic plaques by stimulating smooth muscle cells to grow within the lesions and promoting plaque rupture with resultant thrombosis.
Inflammation significantly contributes to insulin resistance, one of the main factors underlying diabetes.
Finally, psychosocial stress contributes to elevated pro-inflammatory cytokines and reduced anti-inflammatory cytokines in certain individuals. This imbalance can lead to chronic inflammation, which underlies multiple non-communicable chronic diseases. Now, let’s turn back to the part of the autonomic nervous system we discussed earlier that can cause problems when it’s in the “on position” for too long.
Excessive Sympathetic Nervous System Activity and Chronic Diseases
Excessive activity of the sympathetic nervous system is related to cardiovascular disease by increasing the heart’s oxygen demand, causing vasoconstriction, which can lead to ischemia. High SNS activity also affects the direction in which cancer cells will metastasize.
In addition, studies have found that excessive sympathetic activity is associated with an increased risk of cerebral and cardiovascular events in diabetic patients. Additionally, job stress is associated with higher SNS activity among bus drivers. A study on job stress in bus drivers found that driving in peak traffic was associated with elevated catecholamines–neurohormones secreted by the sympathetic nervous system.
Worth mentioning here is that excessive sympathetic activity worsens sleep, lowers hormone levels such as progesterone, and reduces feelings of well-being and the ability to concentrate, all of which are associated with excess mortality. This sympathetic nervous system over-activity translates to feelings of being stressed. But can “stress” cause all of these problems? Turns out, yes, it can.
Let’s talk about stress.
You know by now that “stress” means overactivity of the sympathetic nervous system. Most of us know how that feels, and it’s not pleasant. Acute stress causes symptoms such as a tight, dry throat and stomach, rapid heartbeat, and shallow breaths. It also induces metabolic changes, immune system reactions, and more.
Stress is not a disease or medical condition in and of itself, but it can exacerbate existing conditions or make predispositions to them worse. Whether you experience stress from constantly having to deal with emergent situations at home or work or (for example)- you’re a doctor who treats patients suffering from the consequences of stress, we have all experienced feelings of stress.
Short periods of stress, like strenuous exercise, doing the NYT crossword puzzle, or taking care of a seriously ill patient, can be good for us. Your brain and body work best when the autonomic nervous system cycles easily and rapidly from sympathetic to parasympathetic control.
However, the problem becomes more serious when chronic stress becomes a constant in your life. When this happens, your body never has a chance to switch back to its normal state of homeostasis entirely. This leads to dysregulation of your organs (primarily caused by innate immune cells), which disrupts all the tasks associated with maintaining proper bodily function.
Instead, these cells remain inflamed for too long and, as a result, lose their ability to return to their original state of homeostasis. This then sets the stage for the short-term (and long-term) effects of “too much sympathetic activity”-or simply too much prolonged stress.
That’s when we initially see insomnia, headaches, anxiety, and depression. Eventually, we see autoimmunity, heart attacks, strokes, dementia, and cancer if our stress becomes chronic. It’s obvious: we need to “manage” our stress and address our oxidative stress and inflammation to escape the ravages of chronic degenerative disease.
A Quick Word about Sleep
Although public health experts have been telling us we need a nightly 7-8 hours of quality sleep, this is achieved by only slightly more than half of the U.S. population. We get into bed and turn on phones, tablets, or (horrors!) television. We revisit the events of the day. We have LED’s in the bedroom. We have pets in the bedroom who can interrupt (or enhance, as in my case) our sleep. We know sleep is essential, but why?
There are plenty of reasons, but I’ll focus on what I believe to be the most essential functions of sleep. It’s when the brain does its repair work, using its unique glymphatic system to clean up damaged (and then inherently inflammatory) brain cells. This is also the optimal time for neurogenesis- when we convert our neural stem cells to neurons and create new neuronal connections.
Sleep is also the time when memories get consolidated in the hippocampus. Deep sleep (check that Oura ring!) boosts the immune system, helps weight loss due to several biochemical pathways, and aids in post-workout muscular recovery.
If you’re not sleeping well, chances are that your sympathetic nervous system is involved (and acting up), which means (obviously) that sleeping pills are not “the answer.” What is? You can now answer that question yourself-it’s stimulation of the parasympathetic nervous system. And yes, we’ll get to that, but first, let’s revisit the concept of taking care of a fair amount of oxidative stress, inflammation, and excess sympathetic activity in one fell swoop.
The Vagus Nerve Inhibits Oxidative Stress, Inflammation, and Sympathetic Activity
Now that we’ve covered the basics of sleep and stress (both worsened by the three things that are associated with all chronic diseases (including insomnia and anxiety), let’s talk about how we can get at least some levels of oxidative stress, inflammation, and excess sympathetic activity under a bit of control.
Research has shown that the vagus nerve inhibits all three major disease-promoting biological factors. For example, a study found that vagus nerve stimulation (VNS) reduces oxidative stress. More recently, scientists found that VNS reduced protein oxidation after myocardial infarction, thus limiting heart damage.
Second, the vagus nerve plays a crucial role in neuroimmune communication. It informs the brain about low-level inflammation through its receptors for interleukin-1 (IL-1), a cytokine involved in inflammatory immune responses.
Notably, the vagus nerve inhibits inflammation by activating the hypothalamic pituitary adrenal axis and the splenic nerve. The first mechanism reduces inflammation by secreting cortisol into the bloodstream, while the second works via cholinergic and noradrenergic signals that trigger specific splenic T-cells.
T-cells secrete acetylcholine, which then binds to the alpha-7 nicotinic acetylcholine receptor on monocytes. This causes an inhibition of inflammatory cytokine synthesis. These two routes constitute the vagal anti-inflammatory reflex.
Third, the vagus nerve plays a significant role in the parasympathetic nervous system, which inhibits sympathetic activity. The vagus nerve specifically increases coronary blood flow by stimulating vasoactive intestinal peptide production, which increases vasodilation.
Anti-hypoxic factors are vital in reducing the risk of cardiovascular disease, stroke, and even cancer since many tumors flourish in hypoxic conditions, and hypoxia is prognostic in cancer.
There is evidence that hypoxia (related to excessive sympathetic vasoconstrictive activity), oxidative stress, and inflammation are causally related to a vicious circle. The vagus nerve inhibits all three promoters of the major chronic diseases mentioned above, and empirical evidence supports this relationship.
All this being said, most highly inflammatory diseases such as mold and mycotoxin illness or CIRS, autoimmune diseases, cancer, and most neurodegenerative diseases require more than VNS to get O.S. and inflammation under control.
Now that you know you should learn how to stimulate your parasympathetic nervous system, specifically your vagus nerve, let’s look at how to do this daily.
Vagus Nerve Stimulation
Research suggests that at least three types of meditation may stimulate the vagus nerve indirectly. Loving-kindness meditation, mindfulness meditation, and Om chanting (T.M.) have all been linked to increased heart rate variability (HRV), which is associated with vagal tone, as you now know.
According to one study on ten healthy people, when the body adjusts to cold temperatures, your fight-or-flight (sympathetic) system declines, and your rest-and-digest (parasympathetic) system increases, which is mediated by the vagus nerve. In this study, temperatures of 50°F were considered cold.
Other studies have shown the benefits of living in Finland, where ice swimming and cold plunges keep everyone slightly healthier.
Cold water showers, ice baths (brrrrrr!), cold plunges, and even cold water or ice packs to the face activate the vagus nerve. To get started on this practice, which is incidentally great for your mitochondrial health, finish your daily shower with 30-60 seconds of cold water on the back of your neck. Even I can do this!
Positive Thoughts and Social Connections
Research suggests that positive emotions and social connections improve overall physical health.
In a study published in 2014, 65 participants were divided into two groups: one group was instructed to sit quietly and think compassionately about others by silently repeating phrases like “May you feel safe” and “May you feel healthy,” while the other group did not receive any special instruction.
After participating in the mindfulness meditation course, active participants reported overall improvements in positive emotions. These emotional and psychological changes were correlated with a greater sense of connectedness to others and an improvement in vagal function as measured by heart-rate variability.
I’ve always bought into the adage that “laughter is the best medicine,” even before knowing the physiology of why that is. That said, studies are not numerous nor conclusive. But somehow, we all know this, right?
Several studies suggest that laughter does indeed stimulate the vagus nerve. One study done in a yoga class where participants were allowed to laugh demonstrated that the “laughter group” experienced increased HRV compared to the control group. I have a powerful urge to tell you a funny joke, but I will resist for now.
Singing or Chanting
Heart rate variability has many beneficial effects, including stress resilience and adaptation, relaxation, and increased parasympathetic activity.
One intriguing study on healthy 18-year-olds shows that singing increases Heart Rate Variability (HRV).
The study’s authors found that humming, hymn singing, mantra chanting, and upbeat, energetic singing all increase heart rate variability slightly differently while still involving the vagus nerve.
Finally, singing in unison, often done in synagogues, mosques, and churches, also increased heart rate variability (HRV) and vagus function in this study.
Deep and Slow Breathing
First, let me define what is meant by deep belly breathing. You can do it immediately when you feel the lump in your throat or the rapid ticking of your heart.
Here’s how: Inhale through your nose for 5 seconds. Hold for 5 seconds. Then exhale for 5 seconds out through your mouth. Do this ten times.
Breathing deeply activates the vagus nerve and parasympathetic nervous system. Shallow breaths through the chest and upper body do not activate these systems.
Studies have found that yoga increases the vagus nerve and parasympathetic system activity.
A 12-week yoga intervention was more strongly associated with improvements in mood and anxiety than walking exercises, which served as the control group. The study found increased thalamic GABA levels in participants who underwent yoga, which is associated with improved mood and decreased anxiety.
Yoga appears to have a positive effect on mental and physical health. However, further research is needed to determine the impact of yoga on vagus nerve tone.
Emerging evidence suggests that the gut microbiota may affect brain function. The gut’s nervous system connects to the brain via the vagus nerve, a pathway known as “the interface of the microbiota-gut-brain axis.”
In a study on mice, supplementation with the probiotic Lactobacillus rhamnosus resulted in positive changes in GABA receptors mediated by the vagus nerve.
Research has shown that the vagus nerve, which (as you recall) connects the brain and the digestive tract, might be stimulated by Lactobacillus rhamnosus (a probiotic). This potential link between L. rhamnosus and enhanced GABA activity adds to emerging evidence about probiotics’ potential health benefits.
A deeper dive into Probiotics and GABA
GABA is the primary inhibitory neurotransmitter in the central nervous system and regulates many physiological and psychological processes. Yes, it is the “anxiety neurotransmitter” (if its levels get too low), but it’s much more than simply that.
Studies have found that altered GABA receptor expression may play a role in the development of anxiety and depression, which are highly comorbid with both functional and inflammatory bowel disorders such as Ulcerative Colitis.
In one well-done study, scientists demonstrated that treatment with L. rhamnosus induced brain-region-dependent increases in GABA mRNA in the brains of mice compared with control-fed mice.
Notably, the probiotic L. rhamnosus reduced stress-induced levels of cortisol, as well as anxiety- and depression-related behavior in mice. Moreover, these changes were not found in vagotomized mice, identifying the vagus nerve as a significant modulatory communication pathway between gut bacteria and the brain.
The findings suggest that bacteria play an essential role in the bidirectional communication of the gut–brain axis and could prove helpful in treating stress-related disorders such as anxiety and depression.
A moderate-to-deep pressure massage may activate the vagus nerve. In one study, infants received regular and full massages. These massages helped infants gain weight by stimulating the gut, attributed mainly to vagus nerve activation.
While the evidence is scant, the anecdotal reports are astounding for good old foot massages. In particular, Reflexology foot massages are also thought to increase heart rate variability (and hence vagal tone) while lowering heart rate and blood pressure. This is according to a tiny study on healthy people and another on patients with heart disease.
The vagus nerve activates the muscles in the back of the throat that allow you to gargle. The cranial nerve involved is called the hypoglossal nerve, which runs adjacent to the vagus in the back of the throat.
Gargling contracts these throat muscles, which may activate the vagus nerve.
Sleeping or Lying on Your Right Side
Limited studies suggest that laying on your right side increases heart rate variability and vagus activation more than on your left side. One study found that lying on one’s back led to the lowest vagus activation. If all of this sounds a bit exhausting, you’re in luck! I’m not telling you to avoid healthy foods, activities, stress management, and proper sleep, but I am telling you that you can avoid being fixated on your vagal tone all day. Here’s how.
VNS health benefits
If you don’t have time to do deep breathing, meditation, or any of the things listed above to deal with your vagus nerve symptoms, read on; I’ve got “just the thing” for you coming up soon. Yes, I’ll pre-empt myself: it’s the best vagus nerve stimulator that “has everything” going for it. It works, it’s inexpensive, and it’s a quick usage session. First, let’s see how this device even came to be.
Vagus nerve stimulation (VNS) was developed in the 19th century. Although it did not work well initially, it led to many VNS-related animal studies for seizure control.
Since the 1990s, several early clinical trials have proven the effectiveness of vagus nerve stimulation (VNS) in treating refractory epilepsy and depression. Implantable devices are designed to automate seizure control and for use in heart failure.
Noninvasive transcutaneous vagus nerve stimulators, which stimulate a branch of the auricular vagus nerve, or externally applied devices that work by holding them near the carotid artery-vagus intersection are also undergoing clinical trials for the treatment of epilepsy, pain, inflammation, headache, and much more. These noninvasive VNS devices exhibit greater safety profiles than their invasive counterparts. Speaking of inflammation and brains, let’s take a closer look.
Vagus nerve stimulation for Inflammation and Brain Health
Vagus nerve stimulation (VNS), a stimulating electrode placed on the vagus nerve (in the neck) to deliver low-frequency, intermittent electrical pulses, is approved for refractory depression by the FDA.
VNS affects many brain regions, including those involved in depressive pathology and neurotransmitters such as serotonin and norepinephrine. Research shows that VNS may affect signal transduction mechanisms, including brain-derived neurotrophic factor (BDNF). The exact mechanism of action is unclear at this time.
VNS reduces inflammation by activating the parasympathetic anti-inflammatory pathway, which occurs peripherally (cytokine alterations) and centrally (reduced microglial activation). Stress increases sympathetic excitation, stimulates catecholamine release, and increases brain and peripheral cytokine expression.
The parasympathetic nervous system and acetylcholine release have been shown to have anti-inflammatory effects, which may be responsible for the approximately 50% two-year remission rate for refractory depression with continual, daily use of a vagus nerve stimulator.
Many studies have found that noninvasive vagus nerve stimulation is as effective as direct electrical stimulation for treating refractory epilepsy, pain, Alzheimer’s disease, pain, depression, anxiety, and more.
Autoimmune Disease Potential
Because this is the main focus of my clinical practice, I’d like to give a shout-out to treating autoimmune disorders.
The autonomic nervous system is commonly out of balance in many chronic autoimmune diseases, including rheumatoid arthritis (R.A.), a prototypical immune-mediated inflammatory disease.
Scientists have recently discovered that autonomic dysfunction precedes and predicts the development of symptomatic and seropositive rheumatoid arthritis (R.A.) in people at risk for developing R.A. In addition, R.A. patients with relatively high vagus nerve tone (measured by heart rate variability) respond better to antirheumatic therapies.
These data suggest that a vagus nerve stimulator may help control human inflammation. Experimental studies in animal models of R.A. support this notion by showing that stimulation of the cholinergic anti-inflammatory pathway by efferent electrical vagus nerve stimulation improves clinical signs and symptoms of arthritis, reduces cytokine production, and protects against progressive joint destruction.
The results of these studies, along with previous research in animal models of inflammation, provided the rationale for experimental clinical trials in patients with rheumatoid arthritis. A vagus nerve stimulator has been demonstrated to inhibit human peripheral blood cytokine production.
These studies show that a vagus nerve stimulation device can reduce the production of inflammatory cytokines and improve disease severity in patients with rheumatoid arthritis- even those resistant to other forms of treatment. This work supports further studies using a bioelectronic approach to help treat perhaps all autoimmune disorders.
Let’s talk about how we all “live” for the most part. We try to eat healthfully, get enough sleep, and exercise, but few of us take the time to lower our stress levels. If you look at national statistics on what foods are consumed, what we collectively weigh, how much we sleep (thank you, Oura rings), and exercise, we’re a bit pathetic. Studies hint that most of us live in a stressed, sympathetic nervous system-driven state most of the time.
Ideally, we’d get all these healthy activities and meditation done daily. We’d also regularly have fun with oxytocin-enhancing friend-and-family bonding. And we’d go back to the list in the middle of this article, choosing vagus-stimulating activities to do daily. Yeah, right, you’re busy enough, you are all thinking. Agreed! So what do we do?
Whatever we all do, you now know we need to ensure that our autonomic nervous system is driven by the parasympathetic, not the sympathetic side.
Twenty years ago, getting VNS required an implantable device=surgery. As little as five years ago, it would have required a prescription. Now, we can purchase a VNS health device because we are informed and want one. The best vagus nerve stimulator is small, easy to use, and it just takes two minutes, twice daily, to get the fantastic results described in this article. And no, it won’t cure cancer, but it sure can make you feel much more “chill.” And, of course, lots more than that.
Emerging research suggests that optimizing the vagus nerve’s functioning can help with various health issues, including digestion, mental health, cognitive health, metabolic health, autoimmune disease, and inflammatory disease. And yes, since fat cells are inflammatory, this does indeed help augment weight loss.
More human research is needed to verify and better understand these connections and how the “wandering” vagus nerve impacts overall health, but make no mistake: your health depends on where you “live” regarding your autonomic nervous system. Not just any vagus nerve stimulator is going to cut it. The auricular devices only capture a tiny branch of the vagus nerve. Only one non-prescription item on the market works externally: this particular vagus nerve stimulation device.
Use my discount code: DrKim25, and then use your chosen (and inexpensive!) vagus nerve stimulation device twice daily, in good health!
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Published online 2017 Jun 26.
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