It has been called the wandering nerve, the Buddha nerve, the pneumogastric nerve. Wandering because it is one of the longest nerves (it is actually a pair of nerves) in the human body, reaching from the brainstem to below the waist.

It is called the Buddha nerve because it is associated with relaxation and meditation, and pneumogastric because it has wide-ranging effects in the lungs and gastrointestinal tract.

It is the vagus nerve, from the Latin for wanderer, which has the same root as vague and vagabond. But none of those names adequately describes the wide-ranging influences of this nerve on the way our bodies respond to stress.

The vagus nerve is a part of the parasympathetic nervous system, meaning that it works in the part of our nervous system that is active all the time, mostly without our thinking about it, helping to regulate many of the body’s essential activities, including breathing, heart rate, blood pressure, perspiration and digestion.

The parasympathetic system is our body’s “rest and digest” response. It serves as a counterbalance to the “flight or fight” mechanisms of our sympathetic nervous system, the part that helps us get away from a threat or pull someone from a burning car that we couldn’t lift otherwise.

We need both systems, but optimal health depends on how well the two systems are balanced, or “vagal tone.” With higher vagal tone, you relax quickly after stresses. In that relaxed state, blood pressure, blood glucose and cholesterol are kept at more normal levels making your risk for heart disease, stroke and diabetes lower. Levels of anxiety and inflammation are lower. On the other hand, low vagal tone is associated with increased risk for depression, gastrointestinal disorders and heart disease.

In my medical training and continuing education, until the last five to 10 years or so, there was very little about doing anything to change vagal tone. But we now know that there are lots of ways to influence it for the better.

Vagus nerve stimulation (VNS) is becoming more and more widely accepted for medical treatment of several important illnesses, all commonly found in our aging population.

It can be done in two ways: by implanting a device in the chest that stimulates the vagus nerve in the neck, or by using a handheld device that sends impulses to the nerve through the skin of the neck.

First used for seizures that didn’t respond to medication, it is now used for Parkinson’s disease and often delivers longer-lasting effects with lower doses of standard medications. VNS also appears to work better the longer it is used.

The Food and Drug Administration approved a handheld VNS device for home treatment of frequent migraines in 2018. Patients with depression, anxiety, including post-traumatic stress disorder, and head injuries have also been helped by VNS. Early research suggests that it may help people who have problems with cognition (thinking) to help improving alertness, decision making and memory.

While these medical advances for particular diseases are interesting, all of us can take steps to improve our vagal tone. We don’t have research that proves that activities promoting vagal tone prevent illness yet, but I can almost guarantee that doing any or all of them will make you feel better

First, deep diaphragmatic breathing. Breath through the nose, inhale slowly and allow your upper abdomen to expand as the diaphragm pushes down, then breath out even more slowly. A couple of 5-10 minute sessions a day of this type of breathing have been shown to decrease blood pressure all day.

A splash or two of cold water on your face stimulates the vagus nerve. When your body adjusts to the cold, your fight or flight response decreases and the rest and digest system takes over.

Singing and humming produce vibrations in the neck, which stimulate the vagus beneficially.

Gargling also produces vagal stimulation when muscles at the back of the throat contract. For the most benefit, gargle until your eyes start to water (another vagus nerve function) indicating significant vagal stimulation.

Yoga helps improve vagal tone by incorporating diaphragmatic breathing, chanting and stress reduction.

All types of meditation appear to be good for vagal tone. “Loving Kindness” meditation, which involves directing good thoughts toward other people rather than just attempting to clear the mind, leads to more positive emotions, which appear to improve vagal tone even more.

Finally, laughter reduces muscle tension in the neck, face and diaphragm and involves movement of the diaphragm, all of which have been shown to improve vagal tone. Is it “the best medicine”? I don’t know, but it certainly is fun!

Bert Keller and Bill Simpson write the occasional column, “Aging for Amateurs.” Simpson, a retired physician, wrote this installment. Comments, questions and suggestions are welcome at agingforamateurs@gmail.com.

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