The vagus nerve is the main nerve of your parasympathetic nervous system, the “rest and digest” side that slows you down after stress. It is the longest of the cranial nerves, running from the brainstem through the neck, chest and abdomen to the large intestine, and it helps regulate digestion, heart rate and breathing.1
You can’t switch it on directly, but daily habits that calm the body, slow breathing in particular, are linked in research to more parasympathetic activity.2 Here is what the nerve does, what the evidence supports, and where its limits are.
What the vagus nerve does
Your nervous system has two broad modes. The sympathetic side prepares you for action: “fight or flight”. The parasympathetic side restores you: “rest and digest”. The vagus nerve carries much of the parasympathetic signal.1 Among other things, it helps:
- Digestion: its branches reach the stomach and small intestine, among other organs.3
- Heart rate, blood pressure and breathing.1
- Two-way communication: it carries sensory signals from the organs up to the brain as well as signals from the brain down to them.3
That two-way traffic is why stress so often shows up in the stomach, and why a calmer body tends to digest better. Maria writes about this connection in Rest and Digest: How Your Nervous System Runs Your Gut.
What the research says about breathing
The best-studied everyday influence on vagal activity is slow breathing. A 2018 systematic review in Frontiers in Human Neuroscience found that slow breathing, around six breaths a minute, increases heart rate variability (a common marker of parasympathetic activity) and is associated with more relaxation and less anxiety.2
The same review is careful about its limits: the studies used different methods, and few measured how the body changes and the feelings people report fit together. So slow breathing is a sensible, low-risk habit with research behind it, not a cure for anything.
Simple ways to support rest and digest
- Breathe slowly before meals. A few minutes of breathing out longer than you breathe in, before you eat, helps your body settle into digesting.
- Eat sitting down, without rushing. Digestion works best when the body is not in a hurry.
- Hum, sing or read aloud. All of them lengthen the exhale.
- Move every day. Walking and other gentle movement are part of a calmer baseline.
- Protect your sleep. It is when the body does most of its recovery.
For step-by-step versions you can do in under five minutes, see Five Nervous System Practices That Take Less Than Five Minutes.
What the vagus nerve can’t do
“Vagal toning” is a popular phrase online, and it is easy to find claims that it fixes almost anything. The medical form of vagus nerve stimulation is an implanted device, approved by the FDA for specific cases of epilepsy and depression that haven’t responded to other treatment.1 Breathing, humming and similar habits are not that treatment, and they are not a substitute for medical care.
If you have ongoing digestive symptoms, a racing or irregular heartbeat, fainting, or anxiety that is hard to manage, start with your doctor. Nutritional therapy works alongside that care, not in place of it.
Where nutrition fits
A calmer nervous system makes digestion easier, and steady, nourishing meals make a calmer nervous system easier. Maria works with both sides: regular meals that keep blood sugar steady, foods that suit your digestion, and daily practices that help your body spend more time in rest and digest. Read more about nervous system regulation, or request an appointment.
Sources
- Cleveland Clinic, “Vagus Nerve” (reviewed January 11, 2022). my.clevelandclinic.org
- Zaccaro A. et al., “How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing”, Frontiers in Human Neuroscience, 2018. pmc.ncbi.nlm.nih.gov
- StatPearls, “Neuroanatomy, Cranial Nerve 10 (Vagus Nerve)” (last update November 7, 2022), NCBI Bookshelf. ncbi.nlm.nih.gov
This article is for education and is not medical advice. Maria is a Nutritional Therapy Practitioner, not a physician. If you have symptoms that worry you, please talk with your medical provider.
Maria Zilka, NTP
Maria has practiced nutritional therapy for more than fifteen years. Her work centers on the nervous system, digestion and chronic inflammation. She sees clients in person in Beaverton, Oregon, and by secure video. More about Maria
