Artificial light at night is the metabolic poison nobody warned you about. In Part 1 of this two-part series, Dr. Alan Bradford breaks down what happens when you flip on the lights after sunset.

Timestamps:

00:00 Welcome / Intro

00:46 Artificial Light at Night: The Overlooked Toxin

02:44 Melatonin and Cortisol: Opposing Hormones

04:18 How Light Shuts Down Melatonin (the SCN)

05:51 Light as Low as 8 Lux

06:25 Screens, Blue Light, and Mixed Signals

08:56 Melatonin, Mitochondria, and SIRT3

11:13 Melatonin, Catalase, and Cancer Cells

14:41 Blue Light Isn't the Villain — Timing Is

15:36 What Modern LEDs Get Wrong (the 480 nm Band)

17:53 Four Things You Can Do Today

19:07 Dimming Your Home & Blue-Blocking Glasses

22:04 Sleep Masks and Dark Bedrooms

23:27 Night Shift Work: A Probable Carcinogen

24:22 Next Week: Part 2

Melatonin and cortisol are supposed to work in opposition: cortisol peaks in the morning, melatonin rises at night. But the moment artificial light hits your eyes, your suprachiasmatic nucleus — the body's master clock — tells your pineal gland to shut melatonin production down. Research shows light as low as about 8 lux, roughly half a typical night light, starts that suppression. A tablet screen is about 100 times brighter than the full moon. That matters, because melatonin signals your mitochondria, supports SIRT3, and fuels antioxidant defense, while in cancer cells it depletes catalase and pushes those cells toward apoptosis. Dr. Bradford also explains why blue light isn't the villain — you need it in daytime — and why modern LEDs cause problems by over-emitting 430 to 450 nanometers while omitting the 480 nanometer band. You'll get real, actionable steps: no screens one to two hours before bed, dim household lights after sunset, quality blue blockers, automated dimming, and a solid sleep mask. Plus a sneak peek at next week's guest. Cutting through the medical BS, one light switch at a time.