by Hannah Aylward: The human body never ceases to amaze me…
The way that it is designed to thrive naturally and work fluidly is pure magic. Let’s take a look at one example: the vagus nerve. The vagus nerve, actually comprised of a pair of nerves right and left, extends from both sides of the brainstem just behind the ears, down the neck, across the chest, and through the abdomen. These nerves touch several major organs in your body — stomach and digestive tract, lungs, heart, spleen, intestines, liver, and kidneys. Specifically, it is part of the parasympathetic nervous system. This rest and digest system conserves energy as it slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract.
The vagus nerve is part of the autonomic side of the nervous system. This is the side that just happens without you thinking about it or controlling it. Breathing, heart rate, digestion, and even how we take in, process, and make meaning of our experiences are all directly related to the vagus nerve. It is also primarily responsible for voluntary muscles in the larynx and esophagus, supplying autonomic fibers to the heart and contributing to the gastrointestinal tract. It keeps our heart rate and blood pressure normal, automatically keeping communication between the brain and heart. The vagus nerve also stimulates smooth muscle contraction and glandular secretions in the gastrointestinal tract. It is incredible.
Research shows that a strong vagal tone (toned and working vagus nerve activity) makes the body better at regulating blood glucose levels, reducing the likelihood of diabetes, stroke and cardiovascular disease. Low vagal tone has been associated with chronic inflammation. Strengthening your vagal tone can help relieve brain fog, fatigue, anxiety, depression, and digestive distress.
Vagus nerve stimulation has even been explored as a treatment for depression. In animal models, vagus nerve stimulation has antidepressant-like effects. Animal and human studies have shown that vagus nerve stimulation influences the activity of norepinephrine, serotonin, and other neurotransmitters implicated in mood disorders. Like other antidepressant therapies, vagus nerve stimulation naturally increases the expression of the neurotrophin brain-derived neurotrophic factor (BDNF) and activates its receptor. BDNF is a protein that promotes the survival of nerve cells.
As always, we can support our system’s natural (magical!) functions, or we can work against them. Let’s work with them! So how do we live to support our vagus nerve? Let’s take a look.
COLD EXPOSURE
When the body adjusts to cold, the sympathetic system (fight-or-flight response) declines, while the parasympathetic system increases, which is mediated by the vagus nerve. You can experiment with cold exposure by taking cold showers, trying out cryotherapy, or jumping in that freezing ocean (which feels good in so many ways!).
MEDITATION
Meditation has been shown to increase vagal activity, reduce sympathetic activity and increase vagal modulation. In one study, meditators that deeply practiced loving kindness showed an increase in vagal tone, leaving them feeling happier. Ah, once again meditation comes through.
YOGA + BREATH
Yoga increases GABA, a calming neurotransmitter in your brain. Researchers believe it does this by stimulating vagal afferents, which increase activity in the parasympathetic nervous system. Yogic practices, like pranayama increase vagal tone. Ujjayi breath increases parasympathetic activity as well as heart rate variability. Don’t just take our word for it. Try it out for yourself.
PROBIOTICS
Certain strains of probiotics like lactobacillus have shown to increase GABA via stimulation of the vagus nerve. Another study found that the probiotic strain, bifidobacterium longum, normalized anxiety-like behavior in mice by acting through the vagus nerve. With no surprise, it always comes back to gut health.
SINGING AND CHANTING
Singing at the top of your lungs increases oxytocin and works the muscles in the back of the throat which are connected to the vagus nerve. I know that I feel a deep sense of calm after finishing my practice with an “om.”
LAUGHING
Laughing reduces sympathetic nervous system activity while increasing parasympathetic nervous system activity. This may be caused by the diaphragm stimulating the vagus nerve. There is science behind why it makes us feel so good! Make sure to laugh today, and every day!
