#315 - Can We Treat Disease Through the Nervous System? | Dr. Kevin Tracey & Mike Haney
LEVELS – A Whole New LevelShow Notes
Most of NextLevel starts with a measurement problem: we can see more biology than ever, but we still have to figure out what to do with it. Bioelectronic medicine flips that sequence. We already know how to send electrical signals into the nervous system to change biology, including an FDA-approved vagus nerve treatment for rheumatoid arthritis, even though we still can’t map or read most of the individual nerve fibers carrying those signals.
Mike Haney talks with Dr. Kevin Tracey, a pioneer of neuroimmunology and bioelectronic medicine, about what becomes possible when nerves become a therapeutic target. The opportunity is not simply vagus nerve stimulation, but learning which signals control specific organs, then building systems that can read and write them. That is still some distance away, and Tracey separates it from looser claims about vagal tone and vagus nerve hacks.
Free course: Improve your metabolic health Get our free email course on how glucose, nutrition, exercise, sleep, and measurement can help you build habits that support better energy and long-term health: https://levels.link/wnl
What We Cover: Why the vagus nerve is not one wire How one minute a day became an FDA-approved rheumatoid arthritis treatment Why a nerve target can be more precise than a drug Why mapping the vagus fiber by fiber is only beginning Why CRP and cytokines are not a true inflammation readout What HRV, breathing, humming, and cold plunges can and cannot show
🎙️ About the Guest: Dr. Kevin Tracey is a neurosurgeon, scientist, and President and CEO of the Feinstein Institutes for Medical Research. His work helped establish how the vagus nerve regulates inflammation and helped launch bioelectronic medicine. He is also co-founder of SetPoint Medical and author of The Great Nerve.
📍What Dr. Kevin Tracey & Mike Haney discussed: 00:00 - A nerve can treat one organ. A pill cannot 04:43 - The vagus nerve is 160,000 fibers, not one wire 07:53 - Why the first fiber-by-fiber map of the human vagus is only months old 10:29 - FDA-approved vagus nerve stimulation for rheumatoid arthritis 14:33 - Why one minute a day can quiet inflammation for 12 to 24 hours 17:39 - Why it took 30 years to get from the mouse finding to patients 31:53 - How one minute of current reaches millions of immune cells 41:19 - Why arthritis has a known mechanism and epilepsy and depression do not 49:16 - What single fibers could change in diabetes, the liver, the gut, and stroke recovery 52:59 - Why CRP and cytokine levels still fall short of a true readout 1:04:18 - Resting heart rate, not HRV, is the cleaner vagus signal 1:09:55 - Why deep breathing and humming are not vagus nerve stimulation 1:16:35 - A cold plunge is fight-or-flight first, vagus second 1:20:23 - The spleen signal he would measure if he could
🔗 Helpful Links: The Great Nerve - Kevin J. Tracey (2025) RESET-RA - Nature Medicine SetPoint System - FDA The inflammatory reflex - Nature (2002) Vagus nerve stimulation in rheumatoid arthritis - PNAS (2016), early human study Vagus nerve stimulation after stroke, paired with rehab - The Lancet (2021)
Watch the conversation: https://youtu.be/x_h6Dd_Ap_o Find us on YouTube: https://youtube.com/levelshealth?sub_confirmation=1
📲 Connect: Connect with Dr. Kevin Tracey at Feinstein Institutes for Medical Research
👋 Who we are: Levels helps you understand your metabolic health with personalized data, expert guidance, and tools that connect your daily choices to measurable changes in your body. Our goal is to help you make better decisions about food, exercise, sleep, and long-term health.
Look for new shows every month on A Whole New Level, where we have in-depth conversations with thought leaders about metabolic health.
More from LEVELS – A Whole New Level
Heart disease is the leading cause of death, but it’s also one of the most preventable. Decades of research have established a strong causal role for LDL and other ApoB-containing particles in atherosclerosis, and we now have multiple proven ways to lower them. The harder question is how to turn that evidence into a decision for an individual person. Mike Haney talks with Johns Hopkins cardiologist Dr. Seth Martin, a co-author of the new 2026 dyslipidemia guidelines, about what the latest evidence says we should actually measure and act on. The throughline is pragmatic: lower exposure to atherogenic particles earlier and for longer, use additional tests when they can change a decision, and distinguish interesting new measurements from ones that have actually been shown to improve outcomes.
Most health decisions happen before the science is settled. A study points one way, another points somewhere else, experts disagree about what matters, and even strong population-level evidence may not tell you what will happen to you.
Most medical imaging happens after a symptom, injury, or abnormal test gives a clinician a reason to look. But what changes if imaging becomes a more routine measurement, creating a record of the body before something goes wrong? In this episode of Next Level, Mike Haney talks with Dr. Daniel Durand, chief medical officer at Prenuvo, about whole-body MRI as a test case for a broader shift from episodic medicine toward longitudinal health data. Whole-body MRI is controversial, and Durand is clearly an advocate. The conversation takes the skepticism seriously, then asks a larger question: as measurement gets cheaper, more frequent, and increasingly visible to patients themselves, how should medicine decide what is worth knowing?
Alcohol has spent the last 40 years bouncing between two health narratives: a little is good for your heart, or any amount is dangerous. The science doesn’t really support either slogan. Dr. Tim Naimi has spent decades studying the health effects of alcohol and, just as importantly, why the research is so difficult to interpret. His read of the evidence is less dramatic but more useful: there’s no good reason to start drinking for your health, very low intake may carry little measurable added risk, and risk rises as consumption does. Understanding why earlier studies made moderate drinking look protective helps explain a lot of the whiplashing headlines.
From a single blood sample, new proteomic tools can now measure thousands of proteins at once. Dr. Tony Wyss-Coray’s lab is using that flood of data, together with machine learning, to build a much higher-resolution picture of what’s happening throughout the body and where someone’s health may be headed.