Hacker News Reader

Comment by mercy_dude | Hacker News Reader

Question: how does sunscreen affect these outcome ? I have been in a UV-high indexed area for over 2hrs a day under sun and wondered if applying sunscreen everyday as I have to exposed parts such as arms and legs have negative consequences since all of them have benzene. Now this seems to be another reason for not doing so?

View on HN

Not directly answering your question but related: "early sunscreen formulations were disastrous, shielding users from the UVB rays that cause sunburn but not the UVA rays that cause skin cancer. Even today, SPF ratings refer only to UVB rays, so many users may be absorbing far more UVA radiation than they realize."

https://www.outsideonline.com/health/wellness/sunscreen-sun-...

How can you know if it does both? Look for UVA on the bottle?

Zinc Oxide does. Kid sunscreen is almost always zink oxide to prevent hormone disruption from the nasty stuff they put in adult sunscreen.

The term "broad spectrum" is used to denote UVA/UVB protection in the US, and is an FDA-regulated term.

The UK - and I presume Europe - has a star rating for UVA protection in addition to SPF. Some details here: https://www.nhs.uk/live-well/seasonal-health/sunscreen-and-s...

Tl;Dr - you want minimum 5-star 30 SPF for your daily cream.

Do people actually use sunscreen every day? I wouldn't think a little sun (well before a burn) is that likely to cause problems?

I do. But I live at a fairly high altitude. If I don't put on the sunny, I'll get a bad burn in ~15 minutes of being outside. That's short enough that mowing the lawn or taking a walk will burn me. I got tired of always having a bright red nose or arms that just hurt. So, now I just have a bottle sitting by the door and schmear some on before going out. Also stopped wearing sunglasses, as they make burns worse. Again, I live at altitude.

I do. Aside from sunburns, sunscreen helps to prevent or delay photoaging and reduce inflammatory response to UV in the skin - meaning less acne, rosacea and hyperpigmentation. I use only European sunscreens with proper UVA protection.

Yes the recommendation is SPF15 every day, even in winter.

Many daily moisturisers will have at least SPF15 so it's no hardship since you're already moisturising every day anyway.

Look for PA+++ ratings. You might have to buy sunscreen made outside the US, such as sunscreens made in Korea.

UVB exposure -> p53 activation -> downstream sex hormones upregulation is hypothesized to be mechanism, so sunscreen that blocks UVB will probably reduce the effect.

This study is part of an interesting trend I'm seeing of studies finding beneficial health effects to well timed, full spectrum sunlight exposure. The circadian benefits of seeing early morning sun every day (and darkness every evening) are well known. What's more surprising is that even UV exposure is not purely negative, and in the context of sunlight in moderate amounts (not to the point of acute sunburn) may be beneficial for health:

https://doi.org/10.1093/jnci/dji019 finds that high intermittent sun exposure actually decreases melanoma lethality. I.e. those who avoid the sun die more from melanoma.

https://doi.org/10.1111/joim.12251 found in a study that followed 30k women over 20 years that more sun exposure was associated with reduced all cause mortality. I.e. those who avoid the sun, apply more sunscreen die more in general.

Under these conditions, I would recommend a UPF 50 garment, like Columbia PFG Terminal Tackle Hoody (but I have seen George aka Walmart for $10). I think this is safer than applying chemicals. Also sunscreens in the US are far behind the EU and Asia

https://www.theatlantic.com/technology/archive/2022/07/us-su...

Benzene? I really doubt that. Benzene is almost banned even at labs because it’s so insidious.

Not all sunscreen have benzene, but there have been some recalls because benzene had been found:

https://www.nbcnews.com/business/business-news/banana-boat-s...

https://www.cbsnews.com/news/sunscreen-coppertone-benzene-re...

Reply on news.ycombinator.com