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Comment by krupan | Hacker News Reader

Wow, it feels like nobody read the article. Findings:

- high blood pressure leads to a lot of deaths

- people that spend more time in the sun have lower blood pressure

- skin cancer is caused by sun exposure, but it kills far, far less people than high blood pressure

- people that spend more time in the sun have a lower rate of dying from skin cancer than people who spend less time in the sun!

Summary: more sun exposure makes you less likely to die on at least two fronts!

It's really very simple. You skin adapts to sunlight and doesn't burn if you increase your exposure gradually, and then you get some amazing benefits from it!

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I did[1], and would be curious if anyone is familiar with the underlying study. How did they attempt to control for other factors? (I assume that they did, and am interested to know how)

Also do you have to get a sunburn for sun damage to increase the risk of skin cancers? My understanding was accumulated sun exposure was the issue.

[1] Lindqvist tracked the sunbathing habits of nearly 30,000 women in Sweden over 20 years. Originally, he was studying blood clots, which he found occurred less frequently in women who spent more time in the sun—and less frequently during the summer... decided to look at overall mortality rates, and the results were shocking. Over the 20 years of the study, sun avoiders were twice as likely to die as sun worshippers.

The article cites another study by Richard Weller:

> Sure enough, when he exposed volunteers to the equivalent of 30 minutes of summer sunlight without sunscreen, their nitric oxide levels went up and their blood pressure went down.

I can't find information on the methods for this particular study. So I'm curious if he just set up UV lights on a timer and sat his subjects under them. That's something anyone can set up in their home office if they live somewhere gloomy. Instead of taking a vitamin D pill, turn the timer switch on for 30 minutes of a properly calibrated and positioned low-dose UV light (and out of direct line of sight to anyone not under it)

Or just take a nitric oxide supplement :)

> turn the timer switch on for 30 minutes of a properly calibrated and positioned low-dose UV light (and out of direct line of sight to anyone not under it)

Gosh. Or just go outside! It has the added benefit of being somewhat enjoyable.

Or gosh, just read my comment! I said in somewhat gloomy places. Sometimes people are working when the 10 minutes of sunlight comes out. Often that's not enough time to get down the elevator and get outside before the sun hides behinds the clouds again, even if you can take the daytime break.

Correction. More sun exposure is CORRELATED with being less likely do die. I don't think there's a single causal connection in this article.

You are technically correct. The best kind of correct.

> Sure enough, when he exposed volunteers to the equivalent of 30 minutes of summer sunlight without sunscreen, their nitric oxide levels went up and their blood pressure went down.

That is a causal connection.

Sorry for challenging here, I don’t remember the actual study being linked, and it seems I’m now paywalled and can’t check myself: did he do the same experiment with folks wearing sunscreen? Did he control for relaxation effects? I’d expect both blood pressure to go down and nitric oxide to go up as folks relax, e.g. in a sunny garden or on a tanning bed.

Not sure the “causal connection” is fully established.

NO2 and blood pressure is not the same as death

Or active people spend more time outside and have a lower rate of heart disease, regardless of whether the sun is shining.

That’s not what the article said though. It had nothing to do with physical activity. Ironic considering the comment you replied to

What I got from this is if we mandate the hospitals open their rooms to the sun, the new correlation will cause people to avoid the sunlight because "it leads to more deaths"

I read the article and it conjectures a bunch of stuff but fails to prove it or link relevant studies.

So consider then: we just did a round of "gloves are contaminating basically all micro plastics research" - it might be worthwhile to be slightly skeptical of a suspiciously anti-sunscreen adjacent narrative (coz "sunscreen might be bad for you" is in the article too).

And we should absolutely be suspicious of narratives which have the benefit of confirming someone should do what they already wanted to do: nobody likes putting on sunscreen.

And how strange the conclusion is mostly "you don't need sunscreen" versus "use a lower SPF".

I agree, that article is suspicious. One thing, what if you are not at risk of heart disease? I'm not fat, fairly active, have a low blood pressure and use sunscreen to slow down skin aging. Lots of health advice does not apply to me, cause it is meant for the overweight population. There are the biggest possible health gains to have, so statistically everything that makes people less fat is going to "be healthy for humans".

When standing up from a longer squat I tend to blacken out a bit (never fully fainted) and this gets much worse with sun exposure. So I can totally confirm the underlying scientific finding of this article. Sun exposure does seem to lower blood pressure, but the rest is all conjecture and lacks differentiation.

I guess all the grandmas on the beach that look like they have a leather hide for a skin didn't get the memo that the sun doesn't cause damage after all.

In all seriousness: don't listen to OP, use sunscreen whenever possible.

You are still missing the point. Leathery skin is (by current beauty standards) undesirable but avoiding sunlight is deadly. Pick your poison

There are other ways to lower blood pressure than sun exposure. Article is insane and confuses necessary and sufficient conditions.

It depends on what you use for sunscreen. A lot of sunscreens have aluminum in them and there are many that have it but it is not listed as an ingredient. Zinc oxide sunscreen is a much safer sunscreen.

You seem to be missing what part of that implies "spending time in the sun with sunscreen is risky". Wearing sunscreen doesn't magically make you not exposed at all to the sun. I also think you're assuming it's easy to calibrate your exposure to gradually ramp it up, when I suspect it would probably vary quite a bit by person; some people burn extremely quickly in the sun. Some people who are relatively pale will often need to apply sunscreen hourly to avoid burning.

> Summary: more sun exposure makes you less likely to die on at least two fronts!

Is the “more sun exposure” with or without wearing sunscreen?

That logic is extremely broken. People who spend more time outside do so because of more physical activity. The sun exposure is a side effect. Drawing the conclusion that sun exposure is therefore safe is just totally bonkers.

The study in the article controlled for that

He specifically mentions sunbathers. Not landscapers or construction workers

That is also selection bias. People who spend more time outside relaxing may have lower stress levels? Stress definitely contributes to cardiovascular illness.

Ok, so stop worrying about the exact mechanism, stop arguing on the Internet, and just get outside!

Sigh.

Correlation != causation

It could be that people that spend more time in the sun are busy getting exercise. Which lowers blood pressure.

It could be that people that spend a lot of time in the sun know that they have skin damage, and are more likely to detect melanomas due to more frequent checks of their damaged skin.

Summary: More sun exposure may or may not lead to lower risk of death on two fronts. It seems far more likely that getting exercise and frequent melanoma checks lead to better outcomes, and both of those are correlated with being in the sun, but by no means necessary to the outcome.

Sigh indeed, since that's patently obvious and the study thus controlled for it.

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