Ready to begin or deepen your meditation practice? Join Dan Harris and world-class meditation teachers on the 10% with Dan Harris app here: https://app.danharris.com/membership The vagus nerve is all over social media right now — and most of what you're reading is either oversimplified, unproven, or someone trying to sell you something. This episode is the antidote. Dr. Kevin Tracey is a neuroscientist, physician, and president of the Feinstein Institutes for Medical Research. He is the scientist who discovered 25 years ago that the vagus nerve controls inflammation — a finding that has since led to FDA-approved implanted devices for treating rheumatoid arthritis. His new book is The Great Nerve: The New Science of the Vagus Nerve and How to Harness Its Healing Reflexes. In this conversation, Kevin and Dan cover: - What the vagus nerve actually is — and why Kevin prefers to call it "the great nerve" - Why vagal tone and heart rate variability are real but widely misunderstood — and what your wearable can and can't tell you - The honest evidence for breath work: what we know, what we don't, and why Kevin does it anyway (Pascal's wager) - The specific breathing technique Kevin uses daily: three seconds in, seven seconds out, six breath cycles per minute - What inflammation actually is — and why the vagus nerve is essentially the body's built-in brake on the immune system - The difference between acute inflammation (good) and chronic inflammation (the driver of heart disease, cancer, Alzheimer's, and more) - Cold exposure: the two anti-inflammatory mechanisms at work, why cold showers are safer than ice baths, and the diving reflex - Exercise and vagal tone: what the population data shows — and where the science gets murky - Bioelectronic medicine: the FDA-approved implanted device the size of a fish oil pill that treats rheumatoid arthritis by activating the vagus nerve for one minute a day - Vagus nerve stimulation for treatment-resistant depression: 50% of patients improve significantly — and why most insurance won't cover it - The honest verdict on ear stimulation devices: some intriguing clues, a lot of marketing ahead of the evidence Subscribe to watch more 10% Happier videos: https://www.youtube.com/tenpercenthappier Follow Dan Harris on Social Media: https://www.instagram.com/danharris/ https://www.tiktok.com/@danbharris https://www.facebook.com/DanHarrisABC https://twitter.com/danbharris https://www.linkedin.com/in/dan-harris-91ba5716b/ #neuroscience #mentalhealth #inflammation This episode is sponsored by: BetterHelp — Online therapy, matched to your needs. Get 10% off your first month at https://www.betterhelp.com/happier Spark — Clean energy and focus with zero sugar. Get 30% off and free shipping with code HAPPIER at https://www.drinkspark.com