I speak with Johnathan Jarecki, undergraduate science student and host of The Signal Podcast, on all things photobiology. We discuss the full solar spectrum and how ultraviolet, visible, blue, red and near-infrared light each affect human physiology, including the POMC pathway, nitric oxide and blood pressure, and the evidence on sunlight, skin cancer and the vitamin D paradox. We also discuss how artificial light at night suppresses melatonin and disrupts the circadian control of DNA repair, cardiovascular health, and metabolism. TIMESTAMPS 03:25 Dr. Max Gulhane 04:02 Dr. Gulhane's Love for Science and Medicine 09:01 What is Light? 12:52 Sunlight Broken Down as a Nutrient 14:02 Ultraviolet Light: Sunlight Is More Than Vitamin D 15:56 POMC 21:38 UVA/UVB on Cardiometabolic Health 24:40 Big Picture of UV Light 28:41 Sunlight, Skin Cancer, Dermatology Messaging, The Vitamin D Paradox 35:10 Blue Light, Artificial Light at Night (ALAN), Mechanisms 38:50 Sponsor: Daylight Computer 40:34 ALAN, Epidemiology, Cancer, Heart Disease 45:04 DNA Repair Mechanisms, Circadian Control 47:27 Melanopsin (OPN4), Blue Light, UV Susceptibility 53:25 Red, Infrared, Photobiomodulation, Metabolism 01:00:08 Blue Light, Metabolism, and the Built Environment 01:05:19 Photobiology of Atherosclerosis 01:10:11 Blue Light on Cardiovascular Function 01:12:25 Three M's of Circadian Health 01:18:43 Sunlight, Testosterone, and Reproductive Behavior Full show notes: https://docs.google.com/document/d/15zOnh_l6WOe6237CbQrFPkeoQjUZXIm9Ul4ncQTNXDQ/edit?pli=1&tab=t.0 Show sponsors: 🚨 DAYLIGHT COMPUTER. Blue-light free computer that doesn't wreck your circadian rhythm. Now shipping around the world. Code DRMAX for $25 off. https://buy.daylightcomputer.com/DRMAX 🥩 WOLKI FARM - Regenerative beef shipped around AUS. Highest quality fully grassfed & pastured pork, beef, lamb & eggs raised with holistic principles. Code DRMAX for 10% off. https://wolkifarm.com.au/DRMAX 🚨 VIVA RAYS. Premium blue light blocking glasses with the most useful 3 in 1 clip on frame sets. Code DRMAX for 15% off. https://vivarays.com/dr-maxgulhane 🚨 GEMBA RED. Highest quality photobiomodulation / redlight therapy devices, shipping within the USA. Code DRMAX for 10% off. https://gembared.com 🎤 PRIVATE MEMBERS GROUP on Skool platform - weekly Q&A, my 52-page eBook, PDF resource downloads & more. USD20/month, cancel anytime. https://www.skool.com/dr-maxs-circadian-reset Follow JOHNATHAN YouTube: https://www.youtube.com/channel/UCkMeA454gd3mNubIkaSHyEg Instagram: https://www.instagram.com/jonathanjarecki/ Substack: https://jonathanjarecki.substack.com/ X: https://x.com/jonathanjarecki Follow DR MAX Website: https://drmaxgulhane.com/ Private Group: https://www.skool.com/dr-maxs-circadian-reset Courses: https://drmaxgulhane.com/collections/courses Twitter: https://twitter.com/MaxGulhaneMD Instagram: https://www.instagram.com/dr_max_gulhane/ Apple Podcasts: https://podcasts.apple.com/podcast/id1661751206 Spotify: https://open.spotify.com/show/6edRmG3IFafTYnwQiJjhwR Linktree: https://linktr.ee/maxgulhanemd DISCLAIMER: The content in this podcast is purely for informational purposes and is not a substitute for professional medical advice, diagnosis, or treatment. Never disregard professional medical advice or delay in seeking it because of something you have heard on this podcast or YouTube channel. Do not make medication changes without first consulting your treating clinician. Send us Fan Mail 🧡 HARDBLOCK Australia's Longest Running Bitcoin-only (₿) Exchange Use code REGENPOD for AUD 10 of bitcoin post account verification Support the show