Avoidance of sun exposure as a risk factor for major causes of death (2016)
pubmed.ncbi.nlm.nih.gov
pubmed.ncbi.nlm.nih.gov
Otherwise we are talking about feelings and hunches.
If Google Scholar is providing you with papers (other than this one, which is about rich Swedish people/Swedish people who go outside more) that prove your hypothesis (which you haven't even stated, just hinted at) then you should either link to those papers or not reply.
As for the discussion, there are multiple lines of evidence pointing to the fact that sunlight does in fact reduce mortality. First, this study controls for exercise, and also found that use of tanning beds reduces all cause mortality, so overall it's a pretty good study. We also know that vitamin D status is negatively correlated with mortality. We also know that nitric oxide reduces blood pressure, and is released from the skin by sunlight.
> We acknowledge several major limitations of this study. First, it is not possible to differentiate between active sun exposure habits and a healthy lifestyle, and secondly, the results are of an observational nature; therefore, a causal link cannot be proven.
All studies investigate correlation and that’s okay. Though this discussion overshadows that study’s actual problems.
I wager it’s only on HN because its title is an excuse for everyone to hone their hobby horse opinion on sun exposure.
Which makes me think that the title about "avoidance of sun exposure" is misleading, even if not deliberately so. "Avoidance" in the general lexicon usually means conscious choices to deliberately not expose yourself to something. Is someone who is, say, obese and bedridden "avoiding" sun exposure?
Why call it anything else. I mean it's like me writing a long paper proving that thermodynamics is flawed and then ending the paper with some acknowledgement that one of the key arguments has a logical flaw which renders the whole proof incorrect. So then the whole paper is worthless.
In particular the current consensus is that Vitamin D is essential to health and so this is considering that sun is avoided but replaced by pills, as the protective role of vitamin D is well-proven. But there are many other health benefits that are triggered by sun exposure (the skin metabolism activates and it goes down to influence gene expression).
So I've looked a few articles (at least 7, including some reviewing existing research), and sure enough there wasn't a single paper that actually showing that sun exposure is bad. They all relied on showing on something related to sunlight, most of the time that suntanning with artificial UV beds is really bad. But there it lacks a convincing argument that this transfers to 'the real product', as this is the equivalent of saying that carrots are good/bad for people based on some people ingesting large quantities of carotene in pills. And we know from diet that these kinds of arguments do break down when extrapolating only part of one molecule to a whole, natural product (eggs are a famous example).
If somebody has done more research on this please elaborate, I haven't spent too much time because the research seemed in all cases fairly low quality (questionnaires?) and a lot contained confusing arguments (it's not always clear how dark-skinned the individuals are, or how removed from their natural habitat they are, like some Swedish in Australia or Kenyan in the UK, although some do make an effort in that regard).
My favorite quip regarding this statistical effect is the observation that the cyanide diet is very effective at reducing deaths due to cardiovascular disease (cyanide kills you much faster, so winds up hogging all the credit).
To avoid the mistake, insist on seeing all cause mortality numbers.
you can look at the epidemic of myopia as a related indicator that kids especially are not outside enough
so this whole safetyism nagging about melanoma is ridiculous when they can just go to regular dermatologist screenings and avoid sunburns
- since UV that is filtered out by glass will cause good metabolic reactions, this example takes out the positive of sunlight
- sunlight has a natural "stop it" mechanism. Feeling that you are getting a sunburn would naturally cause you to avoid sunlight, creating therefore a macro regulation mechanism. This is absent from light behind a glass.
So this is showing the exact point I was making that people take something that is not natural sunlight and falsely equate the two.
You seriously suggest the we have mechanism to prevent sunburns? Like the thing people get all the time while at the beach?
It must be very inefficient mechanism since all I remember is that when I notice it i am already sun burned.
You haven't replied to any of the points I'm making, all while making gross scientific errors such as equating glass filtered sunlight to sunlight, so I won't interact any further.
> Four predetermined questions were posed regarding sun exposure: (i) How often do you sunbathe during the summertime? (never, 1−14 times, 15−30 times, >30 times); (ii) Do you sunbathe during the winter, such as on vacation to the mountains? (no, 1−3 days, 4−10 days, >10 days); (iii) Do you use tanning beds? (never, 1−3 times per year, 4−10 times per year, >10 times per year); and (iv) Do you go abroad on vacation to swim and sunbathe? (never, once every 1–2 years, once a year, two or more times per year). The four questions were dichotomized into yes/no in the analysis (i.e. sometimes versus no or never). We created a four-score variable as a measure of sun exposure depending on the number of ‘yes’ responses to the above questions on a scale from 0 (avoid sun exposure: reference) to 4 (greatest sun exposure). Sun exposure habits were categorized into three groups: zero ‘yes’ responses (avoidance of sun exposure; the main study group); ‘yes’ responses to one or two questions (moderate exposure); and ‘yes’ responses to three or four questions (greatest exposure).
Of note, the surveys are of Swedish women and were conducted in Swedish. There could be some translation nuance for the word "sunbathe" which doesn't map well to English, or other cultural differences to explain the "but no one I know actually sunbathes..." thought that I immediately jump to.
Having grown up in Denmark that thought sounds odd to me. People really don’t sunbathe where you’re from?
What do people do on the beach, or in the park all summer? Not to mention at the tanning salon, before going on vacation to sunbathe at the beach (can’t look pale when sunbathing!)
I saw evidence that people sunbathed in some of these locations (it’s obvious on the beaches at least), but as far as I know none of my personal friends sunbathed. I suspect it’s just a cultural thing.
In NZ now - going to beach without protection even for an hour is suicide. Also avoid even going outside from 11am till 3pm at peak summer months.
I live in Western Australia, which is much sunnier than anywhere in NZ, and this sounds hyperbolic to me.
I've met plenty people here who "never wore a hat their life" and look like a prune. Personally I'm more comfortable at home than trying to find a shade everywhere you go.
0: https://www.ehinz.ac.nz/indicators/uv-exposure/daily-uv-leve...
I'd say it is an extremely valuable , indispensable even, item in the scientific toolbelt.
I'm not trying to get a deep dark tan or anything. I just want to make my back and my chest match my arms and face a little bit more closely. Otherwise people laugh at you at pool parties!
Furthermore, people getting too old might make it harder for collective cultural knowledge to evolve. Which is fine in good times, but disadvantageous in volatile circumstances.
Have to admit, your username choice at sign-up was awfully prescient. Don't suppose you want to give me your guesses for any upcoming lottery?
:-)
Vitamin D is essential for the immune system so a correlation between a lack of sun exposure and ill-health seems almost so obvious it's a wonder it needs studying. What would be useful is the exact parameters around sun exposure/vit D metabolism.
A vitamin is a building block, which by itself does nothing; a hormone is a directive, which instructs the body to do something - adrenaline, for example.
Vitamin D2 is a precursor / building block for the hormone D3.
My wife list a battle with melanoma - in her case a single severe childhood burn likely increased her risk by another 25-30%.
Presumably because we need the sun to make vitamin D.
the preference for sun tanned skin to pasty,
https://en.wikipedia.org/wiki/Light_skin_in_Japanese_culture
My loose (and quite possibly wrong) understanding is that this is based on the notion of tanned skin being associated with lower-class women who spent time laboring outside and getting smelly/dirty versus rich and noble women who could sit inside all day.
In America, there is sometimes (often?) discrimination even within an ethnic group based on skin tone, e.g. lighter-skinned vs. darker-skinned African-Americans.
Aren't all of those purely cultural things that have actively changed over the last ~century?
As to the Vitamin D angle, the more I look into it, the more I see that it is a balancing act, and you need other supplements in a particular ratio for it to be more effective.
This Swedish paper’s summary does not differentiate between UV and sun, but assuming it concerns UV—the guidelines will seriously have to change, and ASAP:
> Nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking.
Asian culture avoids sun exposure and sometimes exercise yet are healthier than their Western counterparts who have an unhealthy diet high in fats and sugar in addition to a sedentary lifestyle.
> similar sHR values were obtained when including exercise for those women who answered the second questionnaire in 2000
A bigger caveat tough is this is for Southern Sweden which is rather further north than where the average person in Asian lives. Even if one tries to avoid the sun, the considerably higher UV level and brighter sunlight likely someone is getting more sun than someone who avoids it in Sweden.
While the article seems focused on Vitamin D production, exposure to bright light has a wide range of positive effects on people from mood and sleep regulation to wound healing.
Yes pasty sedentary 40 year old office workers in Beijing avoid the sun. That's not a longitudinal analysis, lifestyles have changed rapidly in the past generation.
What I mean is that Eastern Asian culture in general avoid the sun because pale skin is considered "more beautiful" vs. tanned for Western culture - ex: using umbrellas to cover sun.
Also, myopia epidemic in Asian countries is due to upbringing with strong emphasis in studying indoors but lacking encouragement for sports or outdoors activities: https://news.ycombinator.com/item?id=38782482#38783161
We have no idea what the longevity of the current ~30yo urban east asian will be, but the lifestyle is so radically different than their grandparents that I don't think there's any value in connecting the two.
I ask because, looking around at Americans, so genetically from all over the planet, with a large fraction from Europe, there's a huge dynamic range in diet and exercise levels and it really seems to correlate with the huge dynamic range in external presentation of fitness.
Or that sentence: "Lack of sun exposure is just as bad as smoking."
Do you even hear yourself? Have you taken a statistics course before? How did this even get published?
There are 99999999 other reasons that contributed to mortality. Sun exposure is definitely not one of them.
Exercise and nutrition are the leading factors, period. Who funded this shit