The vagus nerve and inflammation

More than half of all deaths from disease are tied to inflammation, including heart disease, stroke, asthma, diabetes, and autoimmune and neurodegenerative conditions. About a third of people with major depression also have inflammation. Some inflammation is protective, such as the swelling and redness you get when stung by a wasp. This is your immune system dealing with the venom. In such cases, your spleen releases proinflammatory molecules (cytokines) into your bloodstream to activate your immune response, a complex system that includes regulation by the vagus nerve.

But sometimes the immune system can become overactive and damage tissues. In such cases—often the result of stress, chronic infection, or autoimmune disease—inflammation can cause the proinflammatory molecules to circulate continuously for months or years. Examples of an overactive immune system include Crohn’s disease, Parkinson’s disease and chronic pain.

The vagus nerve controls the inflammatory reflex, which includes the delivery of information about inflammation from your body to your brain. In response, your brain—via the vagus nerve—sends signals to your body to regulate its immune response. In the case of chronic, harmful inflammation, the nerve pathway that carries anti-inflammatory signals from the brain to the body may be impaired.  

As with treatment for treatment-resistant depression, scientists are exploring the use of vagal nerve stimulation (VNS) to treat chronic inflammation. The treatment looks promising, as the Pub Med medical journal stated: “Clinical applications have confirmed the efficacy of VNS in managing specific autoimmune diseases, such as rheumatoid arthritis, and chronic inflammatory conditions like inflammatory bowel disease.” This treatment is in its infancy, but worth exploring if you’ve got chronic inflammation.

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