[borski]

The vast, vast majority of Google results do not support your claims. I’m glad you found one that did, and I’m all for more studies, but “it’s really not that hard to google” is both condescending and doesn’t move the argument forward. You are the one making an argument against the established widespread medical opinion; the onus is on you to prove your argument, not on me to prove your argument for you.

https://www.thechildren.com/health-info/conditions-and-illne...

https://pubmed.ncbi.nlm.nih.gov/30945275/

“ There is little evidence that sunscreen decreases 25(OH)D concentration when used in real-life settings, suggesting that concerns about vitamin D should not negate skin cancer prevention advice. However, there have been no trials of the high-SPF sunscreens that are now widely recommended. What's already known about this topic? Previous experimental studies suggest that sunscreen can block vitamin D production in the skin but use artificially generated ultraviolet radiation with a spectral output unlike that seen in terrestrial sunlight. Nonsystematic reviews of observational studies suggest that use in real life does not cause vitamin D deficiency. What does this study add? This study systematically reviewed all experimental studies, field trials and observational studies for the first time. While the experimental studies support the theoretical risk that sunscreen use may affect vitamin D, the weight of evidence from field trials and observational studies suggests that the risk is low. We highlight the lack of adequate evidence regarding use of the very high sun protection factor sunscreens that are now recommended and widely used.”

[toolz]

What exactly do you think my claims are? I'm not the one who made the original claim, only supported the claim that american dermatologists have a zero tolerance policy for sun exposure.

Either you think there's a more representative opinion for American dermatologists than the AAD or what seems more likely is that you don't understand the argument that I was supporting.

[borski]

It is entirely possible we got our wires crossed.

The evidence I actually wanted proof for was the original commenters’ assertion that sunblock somehow raises cholesterol to unhealthy levels.

The quote you chose from the article (which I did read, for what it’s worth, but was also very light on sources) strongly suggested that sunblock blocks Vitamin D production. The science on that is unclear, but prior research suggests it doesn’t; that said, it warrants more research. I took your choice of that quote specifically to mean that was a claim you were making. If that wasn’t the case and you simply meant to show that the AAD suggested not being in the sun without sunblock, then I agree.

The science on melanoma being very bad is pretty cut and dry, on the other hand.

I never disagreed that American dermatologists tend to follow a “zero tolerance” policy for sun exposure without sunblock. They would very much like you to get sun with sunblock, though.

[moritzwarhier]

The cholesterol thing sounded like sarcasm in my ears.

Apart from that, zero tolerance makes no sense - do they really recommend to wear sunscreen on a cloudy winter day? - but it is somewhat debatable that some people still underestimate the destructive effects of overexposure.

And the elefant in the room is of course your skin type.

Couple of my friends have skin of the fitzpatrick type with reddish hair, light skin and many dark spots.

For them sunscreen is a must when I wouldn't even think about it.

Another interesting tangent: wasn't there a somewhat potent carcinogenic in most sunscreen products?

Only makes the tradeoff even harder.

Edit: found it, I meant this:

https://health.unl.edu/can-sunscreen-cause-cancer-how-avoid-...

[borski]

I didn’t sense sarcasm. I could’ve misinterpreted.

Cloudy days still have plenty of UV, depending on where you are (especially near the equator).

Skin type matters, of course, and I would probably be less heavy handed with the recommendation, but the “zero tolerance” issue wasn’t the original point as I understood it.

[edit] Quote from the very article you posted:

“It's important to note that these results are from one study (Valisure), which hasn't yet been validated. Strangely, they also detected benzene in blank test tubes (no sunscreen), leaving some to question if the testing methods contributed to the levels detected.

Toxicologists note that even if you applied the worst sunscreen on the Valisure list to your entire body, you'd be exposed to less than half the amount of benzene you breathe in normal city air in a day. Benzene is also very unstable, so it's unclear how much would be absorbed through the skin.

Don’t let this study convince you to skip sunscreen altogether. Although benzene is a potential risk, it pales in comparison to the known, real risk of UV radiation. Instead, take the time to check that your preferred sunscreen isn’t on the list of contaminated products.”