[HN Gopher] Unexpected benefits of sun exposure on skin
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       Unexpected benefits of sun exposure on skin
        
       Author : robaato
       Score  : 73 points
       Date   : 2023-10-01 17:56 UTC (5 hours ago)
        
 (HTM) web link (www.theguardian.com)
 (TXT) w3m dump (www.theguardian.com)
        
       | [deleted]
        
       | russellbeattie wrote:
       | 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.
        
         | avalys wrote:
         | 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.
        
           | 0134340 wrote:
           | Any many of those sunscreens, if not purely mineral-based,
           | contain endocrine disruptors that can get absorbed into the
           | skin.
        
             | kempfcreative wrote:
             | 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.
        
               | capableweb wrote:
               | 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/20
               | 22-08/sccs_o_244....)
        
       | [deleted]
        
       | wkat4242 wrote:
       | Interesting. I've never been that worried, my skin doesn't burn
       | easily even though I'm very fair-skinned and live in Spain and
       | often hike outdoors.
       | 
       | I just hate that SPF stuff on my skin. It makes it sticky and
       | makes me feel dirty. Instead I just try to avoid burning. I do
       | bring some for when it does start but it almost never does. What
       | I do to avoid it works well enough.
       | 
       | What I tend to do is just take the shady side of the road
       | wherever possible and for the rest of the time just not worry too
       | much unless I really feel I start getting burned. I check that by
       | scratching my skin with my nail, once it starts burning it feels
       | sharper. Then I'd put on the lotion. And by the time I get home
       | my skin will be slightly red but not seriously burned. Which is
       | pretty rare because I tend to tan naturally. By the time spring
       | starts I already have a light brown shade and it protects me
       | during summer. Most of the time I don't even burn at all.
       | 
       | What I do think is bad is someone living in a dark nothern
       | country going on holidays for 2 weeks and spending 2 weeks lying
       | on the beach in the full mediterranean sun. Sunblock or not. My
       | ex used to do that and she got totally burned on the first day
       | even with the sunblock and then spent the rest of the weeks
       | complaining :) I used to live in such a country and I was always
       | more careful during holidays.
        
         | gremlinsinc wrote:
         | I'll just wear light hoodies and sweat pants if I go fishing
         | sometimes my face still gets burned a little because while I
         | don't look at the sun much or get much sun directly to by face
         | because of my hoodie, the sunlight is also reflected off the
         | lake into my face and I often overlook that bit .... I've got a
         | full beard so that blocks most burns now but I've had many
         | really bad burns when I was young 10 to 16 years old . Now I'm
         | 43 and I'm constantly D deficient even on 5000 units daily, if
         | I don't supplement I really feel like crap and get sick more
         | often.
        
         | atombender wrote:
         | There are many sunscreens out there, ranging from greasy and
         | sticky, to completely unnoticeable. My go-to sunscreen of
         | choice is Neutrogena Ultra Sheer Dry-Touch. It's sold in most
         | pharmacies in the U.S. It's lightweight and doesn't feel like
         | you have any sunscreen on at all. There's also a mineral
         | version, but I've not tried it.
        
         | therealdrag0 wrote:
         | I'm also not a fan of the feeling of sunblock. I've learned as
         | an adult that long sleeves and a hat go a looong ways.
        
       | gniv wrote:
       | Article mentions checking the UV index. FYI, on iphone it is
       | shown in the weather app, just need to scroll down a bit.
        
       | ilaksh wrote:
       | Is it just full spectrum light or specific UV sections?
       | 
       | I wonder if future building codes will require some type of
       | intermittent full spectrum or UV light in certain areas. Maybe in
       | a bathroom with a timer that shuts it off a few seconds after
       | someone enters.
        
         | pazimzadeh wrote:
         | You want UVB and not UVA, but UVB is weaker than UVA so all
         | sunblocking type products necessarily enrich your exposure to
         | the bad kind.
         | 
         | The time when the ratio of UVB to UVA is highest (best time)
         | between 10 am to 2 pm, or when your shadow is not longer than
         | your height.
         | 
         | So 20 mins in the sun at noon without sunblock is best, and
         | after that if you're pale then slather on the sunscreen.
        
           | reducesuffering wrote:
           | The article specifically mentions how nitric oxide is only
           | released from UVA activation.
        
             | pazimzadeh wrote:
             | Yeah, just read that and I was going to edit my comment.
        
         | WillPostForFood wrote:
         | Glass blocks most of UVB and a chunk of UVA, so there isn't
         | currently a good solution for indoor full spectrum light
         | exposure.
        
           | hutzlibu wrote:
           | _Normal_ glass blocks most of it. But pure SiO2 fused quartz
           | does not. A bit more affordable is probably borosilicate
           | glass and I would like to have my windows replaced with them,
           | but it is not really sold as a common window. So you can
           | probably get one, but it won 't be cheap.
        
           | ilaksh wrote:
           | I meant like a type of lighting fixture that gives off full
           | spectrum light.
        
       | nu11ptr wrote:
       | This is not even remotely surprising to me. I've always been a
       | bit skeptical of "the sun is evil" (and got even more skeptical
       | when I was told I should wear sunblock inside!) and ensure I get
       | 20 minutes full body exposure daily in the summer. Anecdotally, I
       | can tell a general difference in my mood and sleep during periods
       | where I get adequate sun vs. when I'm not (and I supplement
       | vitamin D when I'm not).
       | 
       | While I am a big fan of the scientific method, it is difficult to
       | do studies that don't have lots of confounding variables in this
       | area, so when in doubt, use common sense is my rule. We evolved
       | with the sun, so the most likely probability is we have at least
       | some defense to it, and more than likely we evolved so that at
       | least some exposure has benefit.
        
         | slashdev wrote:
         | Yeah, that's my thinking as well. I also try to get some sun
         | exposure. I get too little being an tech worker.
        
       | personjerry wrote:
       | I feel like it's known that sun is good for you? But always wear
       | sunscreen!
        
         | hutzlibu wrote:
         | "But always wear sunscreen!"
         | 
         | Sunscreen is full of pretty active chemicals, so I would not
         | recommend using it, when you don't have to.
        
       | graypegg wrote:
       | Interesting, the linked paper [0] does show they controlled for
       | physical activity here, since I would assume someone who gets
       | more sun exposure, is outside more.
       | 
       | If they really have controlled for that factor, shouldn't we see
       | similar results from people with sedentary lives, but high UV
       | exposure? (possibly by regular use of tanning beds or the like?)
       | Being prescribed UV exposure is an interesting idea for the
       | future.
       | 
       | [0]
       | https://www.medrxiv.org/content/10.1101/2023.07.11.23292360v...
        
         | xkcd-sucks wrote:
         | Related, there were some drugs developed to activate melanin
         | production by hooking in to sunlight damage reaponse related
         | pathways, and they do work for light-free tanning. But they
         | were then found to significantly and meangingfully increase
         | libido in men and women, so now there are follow up projects to
         | develop these for erectile dysfunction / low libido. (You
         | probably haven't heard of these because they're all peptides
         | which generally have to be injected without a lot of
         | development work and luck, but the shocking success
         | ofsemaglutide and friends means maybe injection-only peptide
         | lifestyle drugs have a market)
         | 
         | As a general just-so-story rule of thumb to be discounted in
         | the face of evidence to the contrary, stimulus or stress that's
         | a consequence of doing stuff generally acts as a "growth
         | factor" even if it causes slight damage, including exercise,
         | heat and cold shock, and sunlight.
        
           | amelius wrote:
           | https://en.wikipedia.org/wiki/Melanotan_II
        
         | wnoise wrote:
         | It's certainly plausible, but there's a lot of confounds.
         | 
         | Broad-spectrum vs tanning.
         | 
         | And outside also gets lower CO2 and VOC.
        
         | DennisP wrote:
         | In sunlight you also get lots of red and infrared, and there's
         | quite a bit of research on the benefits of that. To replicate
         | sunlight you'd also need bulbs for those frequencies.
        
           | InSteady wrote:
           | IR light reduces certain types of inflammation, speeds wound
           | healing, protects against macular degeneration.. I'm
           | surprised there isn't more interest in its benefits given
           | what we've found so far.
        
         | qingcharles wrote:
         | I feel like they should prescribe sunlight for prisoners. I was
         | held for 10 years without seeing the sun, and many jails and
         | prisons are built on budgets that don't allow for any sunlight.
        
           | olalonde wrote:
           | Do you mean that your cell didn't have sunlight or that you
           | literally never went outside? I was watching a documentary on
           | ADX Florence, which is known for its maximum-security
           | isolation, and prisoners were allowed one hour outside per
           | day.
        
           | zolbrek wrote:
           | That is rough. Perhaps a very stupid question but did you
           | have access to Vitamin D supplementation during that time?
        
       | pkoird wrote:
       | N=1 but I've felt that I always sleep better when I've spent an
       | hour in the sun that day. Considering how the sun has been a
       | constant during much of human evolution, it just makes sense that
       | our biological processes, both known and unknown, should revolve
       | around it.
        
         | api wrote:
         | The obvious thing is that white people are white because they
         | lost natural sunscreen living far from the equator. For that to
         | have occurred the selection pressure must have been fairly
         | strong.
         | 
         | Of course we do know that very heavy sun exposure and
         | especially sunburn can cause cancer. It's probably a case of
         | moderation being good for you-- not too little and not too
         | much.
        
           | Groxx wrote:
           | [delayed]
        
           | bawolff wrote:
           | I think the big question is does it matter outside of vitamin
           | d deficiency.
           | 
           | Severe vit d deficiency obviously is strongly negatively
           | selective. So that by itself explains the evolution of white
           | skin in northern climates. I dont think evolution can be used
           | as evidence for other benefits, since vit d deficiency would
           | cause that just by itself.
        
       | tomohelix wrote:
       | This is no surprise to me since the UV here is actually sunlight
       | related. Lots of co-conditions that affect it too. The paper said
       | they adjusted their numbers for socioeconomic factors but still
       | probably that adjustment won't be perfect.
       | 
       | Anyway, from all I have learned and done, the best health advice
       | that I think applies to most people is moderation is the best.
       | Trying too much and too hard on something will just backfire.
       | Eating only meat and milk will cause cancer sure, but eating only
       | vegetables and beans will also affect your health, namely
       | nutritional deficiency. Etc. and etc.
       | 
       | I will just live normally while adjust things within limits and
       | enjoy life while it is still good.
        
       | jms wrote:
       | I've been living in Australia and New Zealand, and have been
       | terrified of sun exposure - during peak times (summer mid-day)
       | it's scary how quickly you can burn.
       | 
       | However I also have low vitamin D.
       | 
       | My current strategy is to check the UV levels (I've got a widget
       | on my personal dashboard) and whenever the UV levels are moderate
       | or below, I try to get as much sun exposure as possible - shorts
       | and t-shirt, or topless.
       | 
       | I then cover up when the UV levels are demonstrably high.
       | 
       | My theory is that low levels of exposure are very good - you get
       | your vitamin D, whatever else you need, and your body starts to
       | build an appropriate amount of melanin.
       | 
       | The worst thing to do is to avoid sun all the time, then suddenly
       | get massive UV doses.
       | 
       | I've noticed that my hands very rarely get burned compared to
       | other areas - my theory is due to constant exposure that part of
       | my body is more resistant compared to the pasty areas.
       | 
       | My key point is that you can view the UV rating and protect
       | yourself appropriately - e.g. high caution summer-midday, zero
       | caution winter mid-day.
        
         | bostonvaulter2 wrote:
         | Where do you get the UV data from?
        
       | torstenvl wrote:
       | > _Vitamin D is manufactured in our bodies when the UVB rays in
       | sunlight react with a chemical in the skin called
       | 7-dehydrocholesterol. Bone and muscle cells use it to regulate
       | levels of calcium and phosphorus, which are needed to keep them
       | strong and healthy_
       | 
       | If you are at all active over age 30 -- by which I mean you EVER
       | run, jump, or otherwise put pressure on your spine -- you need to
       | get lots of sunlight.
       | 
       | Most people have insufficient if not downright deficient levels
       | of vitamin D. Spondylolysis and eventual spondylolisthesis is not
       | a prognosis you want for your back.
        
         | olivermuty wrote:
         | Most western diets gets more than enough d-vitamin through food
         | additives. Just a couple of slices of cheese per day and some
         | milk is all the d-vit you need here apparently.
         | 
         | The old folk saying is to take d-vitamin supplements in all
         | months that has an R in them. Probably sound advice
        
           | throwaway87651 wrote:
           | "Probably sound advice" ... unless you're in the southern
           | hemisphere!
        
           | smdyc1 wrote:
           | Unless you're living in the southern hemisphere, sure
        
             | [deleted]
        
           | ramblenode wrote:
           | > Most western diets gets more than enough d-vitamin through
           | food additives.
           | 
           | This is just wrong.
           | 
           | Per capita vitamin D defficiency and insufficiency in the US
           | are estimated at about 30% and 40%, respectively [0] compared
           | to about 50% insufficiency worldwide [1].
           | 
           | Lack of exposure to sunlight is a major predictor of vitamin
           | D insufficiency, even in western countries [1]. Sunlight
           | produces more bioavailable vitamin D than dietary sources,
           | and the recommended daily vitamin D can easily be obtained
           | from sunlight alone, while it is hard to obtain from diet
           | alone.
           | 
           | > Just a couple of slices of cheese per day and some milk is
           | all the d-vit you need here apparently.
           | 
           | Daily intake of cheese [2] and milk [3] fortified with
           | vitamin D at the recommended daily value is insufficient to
           | make up for a lack of sun exposure.
           | 
           | [0] https://pubmed.ncbi.nlm.nih.gov/29644951/
           | 
           | [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3356951/
           | 
           | [2] https://pubmed.ncbi.nlm.nih.gov/15956292/
           | 
           | [3] https://pubmed.ncbi.nlm.nih.gov/20460232/
        
           | amelius wrote:
           | Don't forget to take vit K2 too, to get that calcium into
           | your bones instead of your arteries.
        
       | sega_sai wrote:
       | I was about to believe the results as they caution that it's only
       | showing the benefits for northern countries like UK and they
       | control for exercise, but then I saw in the paper that they
       | characterize 'sun-seeking behaviour' variable through 'how many
       | times a year would you use a solarium or sunlamp?'. I think
       | people who use solariums is a very special category of people,
       | and I am not sure one can extrapolate from that group to people
       | who enjoy the Sun.
        
         | 0xcde4c3db wrote:
         | I agree. Despite the "more active" category being anyone who
         | answered that they would use a solarium even once per year,
         | they're still only 6% of the study population if I did the math
         | right (see Table 1 on page 10). It also seems noteworthy that
         | the study cited for that correlation was primarily
         | investigating the factors driving use of tanning beds, not sun
         | exposure.
        
         | cpncrunch wrote:
         | They asked about solarium use, outdoor sun in winter, and
         | summer and various other questions. All showed lower hazard
         | ratio. See table 2 in the 2014Lindquist study.
        
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