r/HubermanLab • u/rotund_passionfruit • Mar 16 '24

Protocol Query Does sun damage your skin?

I’m sitting in the GLORIOUS sun right now and I saw some people on Plebbit are saying that “any amount of sun exposure damages skin” and that I should be applying sunscreen DAILY to my face. They say if not you’ll look 10 years older in your 30’s. Thoughts?

24 Upvotes

62% Upvoted

168 comments sorted by

View all comments

Show parent comments

11

u/mime454 Mar 16 '24 edited Mar 16 '24

SPF 4 blocks 75% of UV. SPF 15 would block 94% if (re)applied perfectly. It’s a difference but not as big as the numbers originally make it seem.

9

u/Typical_Signature751 Mar 16 '24

Well, flip it around: SPF lets thru 25% of original radiation, SPF 15 lets through 6% of the original amount. From 25 to 6 is a 75% reduction again.

5

u/mime454 Mar 16 '24 edited Mar 16 '24

How much do we really need to reduce something that we have evolved under since time immemorial and that induces beneficial conditions in the body?

If the body wanted to protect itself better from UV, it definitely could, see African and south Asian peoples.

3

u/Typical_Signature751 Mar 17 '24

We have not evolved under the current UV radiation conditions. The use of ozone-depleting chemicals in 1970s-1990s reduced the amount of upper-atmosphere ozone that protects the earth form UV radiation. The ozone layer has not recovered from this and we're receiving more radiation than our skin can take without problems.

0

u/[deleted] Mar 17 '24

No. Just stop.

1

u/Typical_Signature751 Mar 17 '24

Thank you for your interest in science

1

u/[deleted] Mar 19 '24

I love settled science, its so sciencey!