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Comment by russellbeattie | Hacker News Reader

I've always been skeptical of dermatologist insistence that sun exposure is unequivocally bad. It never made sense. If human health and lifespan were so negatively affected by sunlight, we would all be covered in fur, or everyone would be as dark skinned as populations living near the equator.

Like everything else in life, "moderation in all things" is the best rule to follow. If you spend your life getting deep dark tans or don't take sensible precautions against sunburns, expect melanoma. If you avoid sunlight like a cave dweller, expect deficiencies in everything from vitamins to mental health.

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> If human health and lifespan were so negatively affected by sunlight, we would all be covered in fur or dark skinned

Evolution doesn't work like that, as long as you procreate you may die at 40 or 120 and genes would not care. Probably a lot more important to get vitamin d from the sun by reducing skin pigmentation when you live near the poles (getting stronger bones and muscles) than slightly reducing your chances of getting skin cancer at 50+ years (most of your peers die a lot sooner of unrelated causes anyways)

> Evolution doesn't work like that, as long as you procreate you may die at 40 or 120 and genes would not care.

evolution doesn’t work like this, either: lifespan can well be selected for on grounds of communal care/ altruism.

No kidding. It seems such an obvious example of industry taking a kernel of truth and blowing it out of proportion to promote a market for themselves. Yes, sunscreen is beneficial in certain situations, but I know some people who slather all their exposed skin with chemicals to "protect" from the sun over the 5 minutes they spend outside while carrying groceries into the house.

Any many of those sunscreens, if not purely mineral-based, contain endocrine disruptors that can get absorbed into the skin.

Can you elaborate on this? I am always ridiculed because I don't want to put on sunscreen for health reasons but I don't remember what the evidence was.

Someone else recommended "Neutrogena, Ultra Sheer Dry Touch Sunscreen" in this submission, and taking a quick look at the ingredients, it does have some I wouldn't put on my skin:

- Octocrylene (endocrine disruptive + might cause sun allergies)

- Butylated Hydroxytoluene (endocrine disruptive)

- Homosalate (https://health.ec.europa.eu/system/files/2022-08/sccs_o_244....)

Yes, sun exposure is bad if you're trying to prevent premature aging. That's why they recommend wearing facial sunscreen on a daily basis.

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