Podcast Episode
Skin Cancer Isn't Caused By The Sun. This Is The Real Cause

About this episode
The sun is not as damaging as you've been told… Zaid Dahhaj shows us where the research breaks.
Zaid runs The Circadian Classroom and studies circadian biology from first principles, which is how he ended up pulling apart the mainstream narrative around melanin, melanoma, and sunscreen.
Once you understand that the research demonising UV is largely built on isolated UV exposure, nocturnal mice, albino mice, and keratinocyte-only petri dishes, the whole "sun causes cancer" story starts to look a lot less airtight.
Melanin gets reframed here as an active defence system rather than damage on a ledger. It's photoprotective, it dissipates UV as heat, and it even chelates certain heavy metals.
Night shift work is classified as a probable carcinogen, and most people are living a low-grade version of it: dark days indoors, and bright nights under LEDs. That's the inversion Zaid keeps coming back to.
We also take a serious look at sunscreen chemistry, vitamin D3, sunglasses and eye health, seed oils and burn risk, and how to build a solar callus without frying yourself on a beach in Costa Rica.
You’ll learn:
[0:00] Introduction
[8:05] Night shift work's carcinogen classification and what it reveals about us all
[11:21] Circadian repair restores UV-damaged cells so there's no accumulated damage
[20:41] The sun-cancer research is built on nocturnal mice and isolated UV
[30:34] The melanoma overdiagnosis problem and dermatology's stage zero caution
[34:26] A tan isn't damage, melanin works as nature's sunscreen
[47:16] The case for actively seeking the sun, and when to do it
[51:58] Sunglasses remove one leg of the circadian stool
[58:46] SPF 50 blocks the very anti-cancer vitamin D your skin needs
[1:09:26] The exact daily routine to build your solar callus without burning
Resources Mentioned:
My Circadian App | Website
Tap Zap App | Website
In Defense of Sunlight by Rowan Jacobsen | Book or Audiobook
Dr. Jack Kruse | Website
A. Bernard Ackerman, MD | Wikipedia
The Rapid Rise in Cutaneous Melanoma Diagnoses by Welch, H.G. et al. | Article
Teo Soleymani, MD | LinkedIn
Use code SUN to get 50% off Zaid’s 80/20 Circadian Course here.
Find more from Zaid:
Zaid K. Dahhaj | Instagram | X | Website
The Circadian Classroom | SubStack
Find more from Ste:
Ste Lane | Instagram
Radical Health Radio | Instagram | YouTube
Heart and Soil Supplements | Website | Instagram | X | YouTube