How Parasympathetic Supports Immune Health

by Jodi Cohen

Your nervous system regulates your immune system and keeps inflammation in check.

This means that the more you stimulate the parasympathetic branch of your autonomic nervous system, the more you can support your immune health, control stress levels and reduce inflammation.

Stimulating your vagus nerve helps to activate your parasympathetic nervous system, which helps to counterbalance your sympathetic nervous system and support healthy immune function.

Just as your car has a gas pedal and brakes, your nervous system has two speeds. The sympathetic fight-or-flight branch automatically helps you accelerate and avoid danger or provides a burst of energy to combat perceived dangers – like stress, injury or infection.

In response to danger, your sympathetic state activates the fight-or-flight response and triggers your body’s immune system to react instantaneously, releasing stress hormones like cortisol and epinephrine (adrenaline) through your body. Your heart rate and blood pressure increase, and digestion slows or stops altogether, as blood is routed away from your internal organs toward your limbs in preparation to fight or flee. Your respiratory rate increases to transport nutrients and oxygen to the cells faster. Your muscles tense and blood vessels in the extremities constrict, sweating increases and if there is an injury or infection, the area becomes inflamed.

Inflammation kicks your immune system into high gear to protect you from more damage so it can heal. During the inflammation process, blood vessels in the area of the damage or infection widen and release more immune system cells into the surrounding tissue.

Inflammation is supposed to be short term.  Once the stress, injury or infection has been adequately addressed, your body is designed to shift back into the parasympathetic state of the nervous system, so your body can relax and your immune system shifts back into balance.

Your parasympathetic nervous system counterbalances your sympathetic nervous system by calming and relaxing the body. It slows your heart rate, reduces inflammation and prevents the immune system from overreacting and over responding.

Your parasympathetic nervous system TURNS ON your immune processes, allowing your body to fight pathogens, bacteria, fungus, parasites, viruses and infections.

In contrast, your sympathetic “fight or flight” nervous system triggers the release of stress hormones that DOWNREGULATES your immune system function to prioritize immediate survival.  This reduces your ability to fight off pathogens, making you more susceptible to pathogens and chronic infections.  This can create a viscous cycle as chronic infections put you into an inflamed state which further triggers the sympathetic nervous system.


Vagus Nerve and Immune Health

The gearshift between the sympathetic fight or flight parasympathetic rest-digest-and-heal branches of your nervous system is your vagus nerve.

It facilitates the state of balance and serves as the on-off switch between the two, as they cannot exist at the same time.

When one fires, it is your vagus nerve that inhibits the other.

When your vagus nerve activates your parasympathetic rest-and-digest state, it dampens your sympathetic fight-flight-freeze state. The yin and yang pull of these two systems keeps your body in balance. Together they ensure that you have enough resources in the right places at the right time.

Your vagus nerve is also the primary channel of communication between your brain and your body.

Derived from the Latin word vagus, which means “wandering,” your vagus nerve wanders through the body, connecting your brain with almost every organ. It facilitates two-way communication—carrying messages from your gut, heart, immune system, and other major organs to your brain.

In response to these incoming messages, your brain releases the appropriate chemical messengers, like hormones and neurotransmitters, that regulate and control all of the unconscious processes in your body, including your immune response.

The vagus nerve innervates the immune organs – including the lymph nodes, spleen, thymus, lungs, liver, kidneys and intestines – and stimulates immune supporting white blood cells called T-cells by secreting neurotransmitters which helps to blunt inflammation.

The spleen serves as an immunological truck stop of sorts, where circulating immune cells periodically park for a while before returning to the bloodstream.  When the vagus nerve is stimulated, T cells release the neurotransmitter acetylcholine, which then binds to the macrophages in the spleen that normally spew inflammatory proteins, known as TNF-α, into the bloodstream. Exposure to acetylcholine prevents macrophages from producing the inflammatory protein.


Why Stress Weakens your Immune System

Stress is known to suppress immune function and increase susceptibility to infections.

Your body’s level of stress hormones are regulated by the autonomic nervous system. When you are stressed, your body turns on your “fight or flight” sympathetic response and downregulates your immune system function to prioritize immediate survival.  This reduces your ability to fight off pathogens, making you more susceptible to infections.

What’s more, the production and circulation of stress hormones like cortisol, epinephrine and norepinephrine signal opportunistic bacteria in your gut to quickly multiply and release toxins that can lead to disease.

  • Sympathetic Survival Mode: When the body goes the “fight or flight” survival mode, it prioritizes fighting to survive in the current moment over fighting infections and down regulates the immune system.
  • Consistently High Blood Sugar: The emergency fuel supply released during a stress response reduces white blood cell activity and depresses the immune system in general
  • Reduced Lymphocytes: Our stress hormones can suppress the effectiveness of the immune system.   For example, cortisol and corticosteroids suppress immune cells, known as lymphocytes which kill invading organisms. With a lowered amount of lymphocytes, the body is at increased risk of infection and disease.
  • Cortisol suppresses Inflammation: Chronic and prolonged stress can set the body up for to resist cortisol and ramp up production of substances that actually promote inflammation leading to a state of chronic inflammation. These pro-inflammation substances, called cytokines, are associated with a host of chronic inflammatory and autoimmune conditions.
  • Poor Immune Signaling: Chronic stress results lower amounts of a protein used to signaling other immune cells. Without these reinforcements, the body is susceptible to contacting acute illnesses, and prolonged healing times.
  • Increased Vulnerability: Long term suppression of the immune system can leave the body vulnerable to infections and disease.

READ THIS NEXT: How Stress Shuts Down the Immune System


Gut and Immune Function

Your intestinal lining in particular is important in immune function. It serves as a physical barrier against any viruses or other pathogens you might swallow, preventing them from passing into your bloodstream.

80% of your immune system resides in your gut, specifically in an area of the ileum known as Peyer’s patches. Peyer’s patches monitor, analyze and respond to the intestinal bacteria in the small intestine to prevent the growth of harmful pathogens. If a dangerous pathogen presents, the Peyer’s patches trigger an immune response – producing antibodies and alerting the immune system to launch a full body immune response to the pathogen before it can spread beyond the intestines.

Research shows that the microbiota, the gut, and the brain communicate through the microbiota-gut-brain axis in a bidirectional way that involves the vagus nerve, which senses gut micro-organisms and communicates with the nervous system to generate the appropriate response.

Healthy gut flora is needed to maintain the healthy balance of bacteria in the intestines. The epithelial cells and the mucosal lining of the gut serve as a physical barrier to pathogens entering the body. Healthy gut flora helps to support the immune functions in the epithelial cells, like maintaining physical and chemical barriers and making the gut more acidic and hostile to invading bacteria. Healthy flora also compete with potential pathogens for space and food. If your healthy gut bacteria are already using all the resources available, there’s nothing left to feed the bad guys. They also help to modulate the inflammatory immune response and neutralize toxic substances.

What’s more, the “fight or flight” Sympathetic nervous system increases the production and circulation of stress hormones like cortisol, epinephrine and norepinephrine which signal opportunistic bacteria in your gut to quickly multiply and release toxins that further overwhelm your immune system.  Opportunistic pathogens are bacteria that are normally present at low levels in your gut where they cause no harm.  When your body is healthy and resilient, these opportunistic pathogens lay low so your immune system doesn’t detect them. But the moment they detect stress hormones, indicating that your resistance is low and you are more vulnerable, they sense “opportunity” and multiply quickly.

One of the most important elements of healing the gut is to eat in the optimal rest and digest Parasympathetic™ state. You can do this by really taking time to sit down, relax, and breathe before eating. We also recommend applying a drop of Vibrant Blue Parasympathetic™ oil to the vagus nerve (behind the earlobe on the mastoid bone) before meals to trigger optimal digestion.

READ THIS NEXT: Support Immunity through the Gut

How Healthy Digestion Supports Immunity

A healthy digestive system supports a healthy immune system for a number of reasons:

  • Properly digested nutrients are the building blocks for supporting our immune system
  • Your immune system is centered in your gut, with 70–80% of your body’s immune cells found in the gut.
  • Your digestive system and intestinal barrier is a key barrier to keep out pathogens, like viruses.
  • Undigested proteins can trigger an immune response, contribute to gut inflammation and put your immune system under greater stress

Proactively supporting your digestion and gut health can help keep your immune system healthy and help you better navigate external threats like the flu and virus.

Digestion is a parasympathetic event.  Your brain sends signals via your vagus nerve to turn on your digestive function and route blood flow to your organs of digestion, which turns on your digestive process:

  • Your mouth releases saliva to both break down your food and as a defenses against disease-causing organisms, such as bacteria and viruses. It contains antibodies that attack viral pathogens. Saliva also contains enzymes that destroy bacteria in different ways, by degrading bacterial membranes, inhibiting the growth and metabolism of certain bacteria, and disrupting vital bacterial enzyme systems (more here).
  • Your stomach produces HCL acid.  In addition to breaking down proteins so they don’t trigger an immune response, stomach acid serves as a chemical barrier against infection, effectively killing any bacteria or viruses that have been caught in mucus in the airways or consumed in food or water.  Low stomach acid is a contributing factor to dysbiotic conditions, like yeast, fungus, bacterial overgrowth, SIBO, or parasitic infestations, all of which profoundly affect your capacity to absorb nutrients.
  • Your pancreas secretes enzymes which in addition to helping your body break down protein, fat and carbohydrates can support your immune system by fighting pathogens in the intestines. Research shows that pancreatic enzymes can support your immune system and calm inflammation.
  • Your gall bladder releases bile.  New research shows that bile acids may help regulate gut immunity and inflammation.  More specifically, bile acids have been shown to exert immune-modulating effect by interacting with immune cells in the gut. “Once bile acids leave the gallbladder and complete their fat-dissolving duties, they make their way down the digestive tract where they are modified into immune-regulatory molecules by gut bacteria.”
  • Your sphincters open and close contributing to motility, allowing nutrients and waste to move through the digestive system and be properly eliminated.  Any kind of compromised motility or constipation can impede absorption of key nutrients, some of which are needed to support the immune system, as well as other side effects such as inflammation and bloating.  Over time, this lack of nutrient absorption and build-up of food matter will weaken your immune system, making you more susceptible to the viruses. Constipation also affects the balance of good bacteria within your digestive system, which is crucial for the strength of your immune system producing substances that drive off or kill invading bugs and viruses.

A poorly functioning brain does not stimulate your vagus nerve, and healthy digestion is not turned on, which undermines a healthy immune system.

To support optimal brain function and enhance digestion, apply a small drop of Parasympathetic™ behind your mastoid bone before meals. When you apply it, take a few deep breaths, with the exhalation longer than the inhalation to fully relax and turn on digestion prior to meals.


The Vagus Nerve and the Inflammatory Reflex

Your vagus nerve triggers your anti-inflammatory reflex which supports healthy immune function and reduces inflammation in your body.

It is the vagus nerve that serves as a detection system for inflammation. The vagus nerve’s vast network of fibers stationed around the organs identify inflammation (such as the presence of inflammatory proteins) and alert your brain to send out anti-inflammatory signals, in essence helping to prevent chronic inflammation in your body.

Your vagus nerve essentially reads the gut microbiome and initiates a response to modulate inflammation based on whether or not it detects pathogenic versus non-pathogenic organisms and decreases levels of pro-inflammatory cytokines.

In the parasympathetic state, your vagus nerve communicates with the rest of the body by releasing the neurotransmitter acetylcholine which acts as a brake on inflammation in your body, inhibiting the production of pro-inflammatory messengers.

Research shows that “targeting the vagus nerve through vagus nerve stimulation has anti-inflammatory properties.” The vagus nerve triggers the cholinergic anti-inflammatory pathway, which can help to dampen peripheral inflammation and decrease intestinal permeability.

READ THIS NEXTParasympathetic for Inflammation


Vagus Nerve Stimulation

Stimulating your Vagus Nerve is the key to turning on your immune system and turning off stress and inflammation.  

Essential oils offer the easiest, most effective, non-invasive strategy to stimulate your vagus nerve and help activate your ability to stay calm and stay healthy.

When applied to the vagus nerve, behind the ear lobe on mastoid bone, the Parasympathetic™ blend stimulates the vagus nerve and triggers the release of the anti-inflammatory neurotransmitter acetylcholine.

Research has shown strong decrease in inflammatory symptoms from stimulating the parasympathetic state. Research also shows that vagus nerve stimulation seems to restore the body’s natural balance. (Study) It reduces the over-production of the chemical messenger that causes chronic inflammation but does not affect healthy immune function, so the body can respond normally to infection.

The primary ingredient in Parasympathetic™Clove essential oil is high in flavonoids, plant compounds that have been shown to reduce inflammation in the brain. Cloves are loaded with polyphenols. Research on clove essential oil has shown robust anti-inflammatory effects that significantly inhibited the increased production of several pro-inflammatory biomarkers.

What’s more, research has found that clove oil, and its key constituent eugenol possesses significant anti-inflammatory qualities and can help inhibit inflammatory responses. (Study)

Research also shows that the limonene found in citrus essential oils is known to stimulate the production of glutathione, an antioxidant known to protect you against inflammation and reduce our chances of developing autoimmunity. Unfortunately, most nutritional supplements of glutathione are not absorbed well and do not raise glutathione levels within the cells, so Lime oil’s ability to help stimulate the production of glutathione inside the cells contributes to the Parasympathetic™ blend’s ability to prevent or reduce systemic inflammation in the gut and the brain.

Consider Parasympathetic™ for chronic infections like:

  • H Pylori
  • Candida
  • Fungal Infections
  • Periodontal Infections (Parasympathetic state triggers saliva in mouth)
  • Chronic Sinus, Respiratory, Gut, or Urinary infections

READ THIS NEXT: Stimulate Your Vagus Nerve with Essential Oils


Essential Oils for Immune Response

Essential oils can specifically be used to help restore immune tolerance by down regulating over-active elements of the immune response and optimizing function of organs that impede or compromise immune function.

Plant compounds like polyphenols and flavonoids have been shown to improve blood flow to the brain and reduce inflammation in the brain (Study). The process of distilling these concentrated plant essences into essential oils makes them more accessible to the brain to help calm brain inflammation.

Essential oils possess many antibacterial, antibacterial, antiviral, and antifungal compounds that help kill germs, fighting off a wide range of bacteria, viruses, fungi and infections, calm inflammation and prevent illness. For example, hot oils (that induce a warming sensation) like cinnamon, clove, eucalyptus, rosemary and Oregano can help stimulate your immune system and boost immunity.

Essential oils have also been recognized for their immune modulating properties.  Recent research found that an essential oil blend of wild orange, clove, cinnamon, eucalyptus, and rosemary “exhibited significant effects on the levels of protein biomarkers that are critically involved in inflammation, immune modulation, and tissue remodeling processes. The overall inhibitory effect of EOB on these protein biomarkers suggests that it has anti-inflammatory and immune modulating properties.”  The study also found that the essential oils “robustly affected signaling pathways related to inflammation, immune function, and cell cycle control.”


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About The Author

Jodi Sternoff Cohen is the founder of Vibrant Blue Oils. An author, speaker, nutritional therapist, and a leading international authority on essential oils, Jodi has helped over 50,000 individuals support their health with essential oils.

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Subscribe to Vibrant Blue Oils and receive weekly information on oils and how to use them. As a bonus, we’ll send out Beginner’s Guide to Essential Oils to your inbox immediately!