[HN Gopher] Exposure to the Sun's UV radiation may be good for you
       ___________________________________________________________________
        
       Exposure to the Sun's UV radiation may be good for you
        
       Author : beefman
       Score  : 145 points
       Date   : 2024-08-20 16:23 UTC (6 hours ago)
        
 (HTM) web link (www.economist.com)
 (TXT) w3m dump (www.economist.com)
        
       | beefman wrote:
       | https://archive.is/tqZsD
        
       | Hendrikto wrote:
       | > According to Richard Weller, who co-led the study, most uv
       | exposure guidance has thus far been firmly focused on preventing
       | melanoma skin cancer. But, he says, "Many times more people die
       | from other cancers and diseases. We have to think about how uv
       | radiation could help them avoid illness."
       | 
       | > The exact mechanism whereby uv light might lengthen lives is
       | unknown. The authors, for their part, believe part of the
       | explanation may lie in vitamin D's ability to boost the immune
       | system and improve bone health. They also point to nitric oxide,
       | a potent blood-vessel widener capable of reducing the risk of
       | cardiovascular disease.
        
         | aurareturn wrote:
         | So why can't we just eat more Vitamin D supplements?
        
           | davidcollantes wrote:
           | The sunlight is free. :-)
        
           | hollerith wrote:
           | There are 4 beneficial effects of sunlight I know of that
           | have nothing to do with vitamin D.
        
             | kstrauser wrote:
             | I know 5.
        
               | hollerith wrote:
               | My 4:
               | 
               | Light that is brighter than is possible inside most homes
               | makes you more alert (almost immediately), and if done
               | during the first 3 hours of wakefulness has benefits that
               | last throughout the day according to Andrew Huberman.
               | 
               | Specific qualities present in sunlight when the sun is
               | very low in the sky (or under the horizon, namely yellow-
               | blue contrasts detected by the intrinsically-
               | photosensitive retinal ganglion cells) entrain the body's
               | clock, making it easier to get to sleep at a consistent
               | and suitably early time of day.
               | 
               | UVB exposure triggers a skin-brain-gonadal axis through
               | skin p53 activation (nothing to do with vitamin D). I.e.,
               | 20 or 30 min every other day of strong sunlight on bare
               | skin and into your eyes increases your levels of the sex
               | hormones.
               | 
               | Certain red and infrared wavelengths help cytochrome c
               | oxidase turn serotonin into melatonin, which is a potent
               | antioxidant right where antioxidant activity is most
               | needed (in the mitochondria).
               | 
               | What's the fifth one?
               | 
               | ADDED. It just occurs to me that with "I know 5" the
               | conversation might have jumped from the object level to a
               | comment on the social and emotional effects of my
               | comment. D'oh!
        
               | kridsdale3 wrote:
               | THERE ARE FOUR LIGHTS
        
               | Temporary_31337 wrote:
               | The 6th reason is being smarter than the other two guys.
        
           | Etheryte wrote:
           | For one, your body absorbs an abysmal fraction of
           | supplements, nearly all of it comes back out the other end.
           | This isn't unique to vitamin D, naturally, but for
           | practically all food supplements. Your body is pretty good at
           | taking care of itself so long as you give it the tools it
           | needs. If you live in a northern climate, vitamin D
           | supplements may be a part of it, but for most part, spending
           | some time outside and getting your movement in is a
           | reasonable baseline.
        
             | Aurornis wrote:
             | > your body absorbs an abysmal fraction of supplements,
             | nearly all of it comes back out the other end
             | 
             | This is irrelevant when the supplements are available in
             | high enough doses to overcome poor availability.
             | 
             | It's not hard to exceed the upper limits of serum Vitamin D
             | with common higher-dose off the shelf supplements if taken
             | long enough.
        
           | _bin_ wrote:
           | You can, and it's quite possible that provides most of the
           | benefit. But very few systems in the body operate in total
           | isolation, and it's equally possible something else depends
           | on vitamin D synthesis or on UV absorption, and that thing
           | might matter for health.
        
           | lukan wrote:
           | In short, because the body and the mind is a very complex
           | system.
        
           | Hnrobert42 wrote:
           | I know almost nothing about this apart from being vitamin D
           | deficient and taking supplements. My doc says that vitamin D
           | absorption through the gut is much less efficient than
           | vitamin D created by the body.
        
           | kingkawn wrote:
           | because its a reductionist view of the value of sunlight
           | exposure
        
           | gruez wrote:
           | >They also point to nitric oxide, a potent blood-vessel
           | widener capable of reducing the risk of cardiovascular
           | disease.
        
           | pmahoney wrote:
           | This paper, "Insufficient Sun Exposure Has Become a Real
           | Public Health Problem" [1] states "thus, serum 25(OH)D as an
           | indicator of vitamin D status may be a proxy for and not a
           | mediator of beneficial effects of sun exposure".
           | 
           | That is, while vitamin D can be used to deduce someone's
           | amount of sun exposure, the benefits of sun exposure are not
           | coming from the vitamin D.
           | 
           | [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7400257/
        
           | jmward01 wrote:
           | In his TED talk, Weller gives a potential alternate benefit
           | source in nitric oxide production which leads to potential
           | cardiovascular benefits. So, the short answer is it may not
           | be (just) vitamin-d. The bigger point though is that there
           | are a lot of very complex things that happen when you go
           | outside and benefits could come from many of them. We want an
           | easy 'this one thing happens so we can replicate just that'
           | but maybe it is actually a combination of many things so
           | there may be no easy one pill replacement.
        
             | kridsdale3 wrote:
             | Two pills then: Daily 10,000 iu D and daily Cialis. Bonus:
             | Bon-us.
        
           | cpncrunch wrote:
           | Because studies into vitamin D supplementation haven't shown
           | that it reduces mortality, and because there are other
           | benefits of sunlight, such as nitric oxide.
        
             | Wissenschafter wrote:
             | Ok, just add L-Arginine supplementation then...
        
               | cpncrunch wrote:
               | So how do you explain the reduction in cancer mortality
               | with sunlight?
        
               | Wissenschafter wrote:
               | Did this study factor in supplementing for other things
               | sunlight provides, i.e. the nitric oxide? If not, then
               | it's a poor study in relation to supplementation as a
               | means of obtaining the benefits of sun exposure.
        
               | cpncrunch wrote:
               | No studies have shown that any of these supplements
               | reduces mortality, whereas multiple studies show sunlight
               | reduces mortality.
        
           | kragen wrote:
           | because the exact mechanism whereby uv light might lengthen
           | lives is unknown
           | 
           | when your skin synthesizes vitamin d using sunlight, it
           | synthesizes it from cholesterol. i wonder, does that lower
           | serum cholesterol? if so, which serum cholesterol?
        
           | pazimzadeh wrote:
           | People who get plenty of vitamin D through their diet still
           | benefit from sunlight exposure
           | 
           | Ecological study of solar radiation and cancer mortality in
           | Japan https://pubmed.ncbi.nlm.nih.gov/15551791/
        
         | jmward01 wrote:
         | He has a good TED talk on this from over a decade ago.
         | https://www.ted.com/talks/richard_weller_could_the_sun_be_go...
        
         | trhway wrote:
         | another effect - collagen mixed with vitamin B polymerizes in
         | UV, thus eyes and skin repairs for example.
         | 
         | The biggest issue is non-managing mismatch between your
         | geographically evolved skin type and the Sun in the geography
         | you're residing - thus white people living south get a lot of
         | skin cancer while for example Somali immigrants in Minnesota
         | and Sweden have widespread severe vitamin D deficiency (and
         | associated issues)
         | 
         | Tangential - a pet theory of mine is that 40K years ago when
         | magnetic field flipped, and there was short period (1K years or
         | so) of highly increased UV it led to large number of early eyes
         | issues in those large eyed (most probably the result of
         | evolutionary adjustment to the more northern light)
         | Neanderthals living in Europe - early damaged vision,
         | cataracts, blindness - while Cro-Magnon's eyes with Cro-Magnon
         | just coming out from Africa, faired much better with that
         | northern, even temporarily increased, level of UV and thus the
         | Cro-Magnon quickly replaced the Neanderthals.
        
         | MrBuddyCasino wrote:
         | I don't understand how this is surprising for people.
         | 
         | We have evolved under the sun, of course we have adapted to its
         | presence, and taking it away naively is unadvisable.
        
           | colechristensen wrote:
           | People are generally taught things like this through mildly
           | hysterical news broadcasts from moralizing non-specialists.
           | This is why it's surprising for people. They've been taught
           | the sun is scary.
           | 
           | If you don't put sunscreen on your kids, it's tantamount to
           | abuse. (I recently experienced this walking through the woods
           | at 10 AM with a family member, no I don't need any sunscreen
           | for a short hike through the trees)
        
           | davidw wrote:
           | People evolved to live in a fairly small area of the world
           | rather than flying to distant places with different amounts
           | of sunshine than our ancestors likely dealt with in the areas
           | where they spent generations.
        
           | matsemann wrote:
           | I don't buy that as an argument. It's the same argument used
           | to push all kind of hoaxes or fad stuff. We live longer than
           | what we used to do, so not everything we did in the stone
           | ages can have been beneficial.
        
             | throwaway4aday wrote:
             | Average lifespan has increased, meaning more people survive
             | early deaths due to disease and injury that we can now
             | prevent, but as individuals we haven't broken through any
             | maximum age barriers.
             | 
             | That said, sun bathing is a modern phenomenon. Our
             | ancestors knew enough to assess that painful sunburns were
             | bad and mitigated their exposure by wearing large hats and
             | clothing with long sleeves. I'm sure even primitive peoples
             | would cover themselves when necessary. If you spend a lot
             | of time working outside you also develop a very dark tan
             | which helps quite a bit. Modern people seem to suffer
             | mostly from spending so much time indoors that even
             | moderate sun exposure on the weekend produces a damaging
             | sunburn.
        
         | Bjorkbat wrote:
         | Something I've found rather curious is that my home state of
         | New Mexico has the lowest cancer incidence rate out of any
         | other state US state (Puerto Rico is lower, but technically not
         | a state) (https://statecancerprofiles.cancer.gov/incidencerates
         | /index....).
         | 
         | Now, granted, your risk of dying from heart disease is actually
         | greater than that of cancer, so it's entirely possible that the
         | low cancer rate is because everyone is dying from heart disease
         | instead. It would make a lot of sense since New Mexico is one
         | of the poorest states in the country.
         | 
         | Thing is though, the heart disease mortality rate is also low. 
         | (https://www.cdc.gov/nchs/pressroom/sosmap/heart_disease_mort..
         | .)
         | 
         | So I don't know, I'm kind of inclined to that our low mortality
         | rates might be due to the sun instead. On top of being located
         | further south than most states, we also get more UV exposure
         | due to our higher elevations, and most days are relatively
         | cloud free. Other theory of mine is a more Latin-influenced
         | diet and exercise, but again, we're a poor state, poverty tends
         | to be negatively correlated with exercise and diet.
         | 
         | It's a trend followed by most of the Mountain West, which is
         | roughly as arid and sun-rich as New Mexico. I just find New
         | Mexico so interesting because it definitely dispels any notion
         | that people are healthier because they're richer or have access
         | to better health care.
        
           | klipt wrote:
           | This is called the Hispanic Paradox, there's even a wiki page
           | on it.
           | 
           | Hispanic people have better health outcomes despite being
           | poorer, probably due to better diet, exercise, community
           | structure etc.
        
       | xnx wrote:
       | This is probably even more complex than "The dose makes the
       | poison". UV has some benefits and other known drawbacks (e.g.
       | skin damage and cancer).
        
         | tantalor wrote:
         | That adage only really applies to chemical toxicology.
         | 
         | It doesn't work on non-chemicals: UV, radiation, noise,
         | heat/cold, pressure, physical trauma, repetitive motion,
         | exertion, posture, etc.
        
           | jkingsman wrote:
           | I would argue it certainly does -- heat/cold is comfort vs
           | injury. Pressure is massage vs. crush injury. Trauma, I
           | suppose, is definitionally bad. Repetitive motion is muscle
           | mass and strength increase vs RSI. Exertion is cardiovascular
           | health vs exhaustion. Posture, I'll give you -- I don't think
           | there's such a thing as posture that is /too/ good as long as
           | you're staying mobile/stretching/taking breaks.
           | 
           | Perhaps a more intuitive way of stating it is, "Some
           | classically bad things can be good in small or optimized
           | doses. Some classically good things can be bad when taken to
           | excess."
        
           | crowcroft wrote:
           | Strictly speaking yes, but I think it can be applied well
           | enough in some cases to things like exertion/repetitive
           | motion when thinking about specific contexts.
           | 
           | Running is good for you, running 20km every day for years
           | will prematurely destroy most people's knees.
           | 
           | I guess applying the adage in that way makes it become a
           | tautology though, too much is in fact, too much.
        
           | lxgr wrote:
           | Most of which are in turn influencing biochemical processes
           | in an organism, so I'd say the point still stands.
        
         | cpncrunch wrote:
         | But the benefits seem to outweigh the risks. Mortality from
         | cancer, including melanoma, is lower with higher sun exposure.
         | We have known this since Berwick's 2005 study into mortality
         | from Melanoma, and Lindqvist's 2016 study showed that all-cause
         | mortality was reduced with UV exposure.
        
       | office_drone wrote:
       | This reminds me of the story of the Taiwanese radioactive homes,
       | where 2000 homes were built with radioactive materials. There was
       | a prediction that a lot of the inhabitants would die of cancer,
       | and that didn't really happen.
       | 
       | https://www.todayifoundout.com/index.php/2020/12/the-curious...
        
         | lxgr wrote:
         | The general concept is called Hormesis:
         | https://en.wikipedia.org/wiki/Hormesis
         | 
         | It's one reason why the "linear no-threshold" model for
         | biological effects of radiation is probably not accurate:
         | https://en.wikipedia.org/wiki/Linear_no-threshold_model
        
       | calibas wrote:
       | "Avoiding Sun as Dangerous as Smoking"
       | 
       | https://www.medscape.com/viewarticle/860805?form=fpf
        
       | the__alchemist wrote:
       | Note: preventing photo aging by limiting exposure to UV, is
       | currently the single biggest thing you can do to slow [an aspect
       | of] visible aging.
        
         | tasty_freeze wrote:
         | I'm 60, and from mostly Irish descent -- meaning I burn easily
         | and don't really tan much. I've never been a beach-goer/sun-
         | bather. The sun I get is just incidental to mowing the lawn,
         | walking the dog, etc.
         | 
         | The skin on my arms looks like a typical 60 year old --
         | spotted, thin, little elasticity. But lift up my sleeve and the
         | skin of my upper arm and shoulder look like that of a 20 year
         | old. My torso skin is young too, but it is weird to demonstrate
         | that to young people.
        
           | deepfriedchokes wrote:
           | Ben Franklin said about the same of older women!
           | 
           | https://en.wikipedia.org/wiki/Advice_to_a_Friend_on_Choosing.
           | ..
        
         | slothtrop wrote:
         | Isn't sunscreen use enough?
        
           | the__alchemist wrote:
           | It can be.
        
           | lucius_verus wrote:
           | Very few people use the recommended amount of sunscreen (it's
           | more than you think) and even when you do, no sunscreen
           | blocks 100% of the photo-aging UV energy that hits your skin
           | (note: still wear sunscreen - absorbing 5 or 10% is better
           | than 100% of the radiation you would otherwise absorb). This
           | also means that (contrary to what weird sunscreen-truthers
           | will tell you) wearing sufficient sunscreen does not prevent
           | you from producing vitamin D - sunscreen is not the same as
           | never seeing the sun.
        
         | qingcharles wrote:
         | I recently went 10 years without seeing the sun, and I
         | definitely think it had an anti-aging effect on my skin.
         | 
         | I worry about what _aging_ effects it had _inside_ my body,
         | though, being without for so long.
        
       | JoshTko wrote:
       | I've started to ignore studies these days that contradict how
       | most humans would have lived, for most of humanity. Most humans
       | would have had plenty of sun exposure and genetics would have
       | adapted accordingly. I'll seek as much sun exposure I can on work
       | days, but will never sun bathe for hours on end.
        
         | cameldrv wrote:
         | It depends on your skin though. If you're of European ancestry
         | and living in a sunny place, your genes haven't had enough time
         | to adapt.
        
           | reustle wrote:
           | Yes, this is the nuance so many of these discussions miss.
           | 
           | Keep a close eye on your local UV forecast, avoid peak times,
           | and you should be pretty good.
        
           | mint2 wrote:
           | Exactly, a Northern European adapting to sun exposure doesn't
           | mean getting a tan, it would mean evolutionary pressure to
           | adapt to, say, sunnier California via natural selection over
           | a few thousand years where less sun fit portions die off
           | earlier, while the surviving group slowly gets darker over
           | many many generations or better at repairing damage.
           | 
           | If you're fair skinned but find yourself outside the low UV
           | region that your skin is adapted to, you are welcome to begin
           | the new adaptation by avoiding sun protection and going
           | outside without regard to the UV index.
           | 
           | I, however, will not join that genetic adaptation.
        
         | archagon wrote:
         | Genetics would have adapted if it affected reproductive
         | fitness. But skin cancer tends to develop past reproductive
         | age.
        
       | troymc wrote:
       | The article is about a new paper in the journal _Health & Place_.
       | That paper is open access and can be found at:
       | 
       | https://www.sciencedirect.com/science/article/pii/S135382922...
        
         | chromatin wrote:
         | > * Public health messaging on sunlight exposure may need
         | reconsideration.
         | 
         | no kidding
        
       | taeric wrote:
       | This always strikes me as a tough discussion. With the odd
       | hostility between the two extremes of "all sun is bad exposure"
       | and "you should get more sun." With the later taken to be "all
       | sun is good exposure."
       | 
       | Just observing a typical yard, it is easy to see that grass can
       | both have too much and too little sun. Indeed, cover it up and it
       | will die. Expose it to direct sun all day for several days with
       | no water and it will similarly die. (Well, not similarly, it will
       | die in a different way.)
       | 
       | I realize we don't photosynthesize, and burning is clearly bad
       | for us. But I don't understand why people seem so resistant to
       | the idea that some sun is probably beneficial.
       | 
       | I also realize that literally "basking in the sun" is almost
       | certainly taking it too far. :(
        
         | tossandthrow wrote:
         | > Expose it to direct sun all day for several days with no
         | water
         | 
         | This would appear to be an indication of lack of water and not
         | too much sun.
        
           | taeric wrote:
           | I'm fine saying it is complicated. So, Maybe? I have grass
           | right next to some that does not die due to the sun exposure.
           | But it is shaded for large portions of the day, there.
           | 
           | All of that is to say, I don't think you can or should reduce
           | this down to only sun exposure. There is more going on.
        
             | tossandthrow wrote:
             | I absolutely agree on your premise - that sun, like most
             | things, is about moderation.
             | 
             | I was just pondering on the example you gave: Is there a
             | case where grass will die out from sun when that is the
             | isolated factor? I would assume that there is, but I am not
             | sure it is given.
        
               | taeric wrote:
               | Totally fair and I don't know. My yard actually has a
               | sprinkler system, such that I don't think I'm flat out
               | not watering it in the sunny time of the year. You can
               | definitely see where the sun hits the yard for longer,
               | though.
        
           | AlexandrB wrote:
           | Grass is a terrible analogy here. Try putting a moth orchid
           | or many ferns in direct mid-day sun and they'll quickly die
           | no matter how much water is available.
        
         | _heimdall wrote:
         | I believe it goes back to an over generalization that nearly
         | all skin cancers must be caused by exposure to the sun's UV
         | rays.
        
           | fridder wrote:
           | And the fact that general medical advice is often geared
           | towards the common denominator. Folks who are not great an
           | nuance
        
         | sherburt3 wrote:
         | Same thing with exposure to bacteria, too much and you get the
         | bubonic plague, too little you get autoimmune disorders.
         | Moderation is key.
        
         | simonbarker87 wrote:
         | Agree! I think people are sooo scared of cancer (which is
         | understandable) and have had 15 years of the sun screen
         | industry beating the "always wear sun screen" drum (not that
         | they are financially incentivised here at all!) that many
         | people now just equate "sun = bad" because grey areas are hard.
        
           | addicted wrote:
           | The financial incentives for the sunscreen industry works
           | both ways. If all sun exposure is bad people will minimize
           | going out and sunscreen sales would plummet (no one is
           | wearing sun screen while sitting in their homes).
           | 
           | So, in fact, the sunscreen industry is entirely incentivized
           | to push the "the answer is always at the center of the
           | extremes" mantra that is being repeated in this comment
           | thread. Because that's maximizing the use of their product
           | because people will still go out to get the benefits of the
           | sun but need to apply sunscreen to avoid the negative
           | effects.
        
             | zh3 wrote:
             | I expected far more comments about how the profit motive so
             | often manages to drown out the scientific evidence; little
             | disappointed how far down the page I was before I saw
             | yours.
        
           | caeril wrote:
           | It's also useful to note that skin cancer is very easy to
           | catch early. Melanoma is definitely not something you want to
           | have if you catch it late, but early detection is cheap
           | (equipment required: eyes and a mirror) and easy.
           | 
           | Treatment prior to melanoma reaching the capillaries is also
           | relatively cheap and easy (excision with margins), and
           | extremely successful (>99% remission).
           | 
           | Median time between "that mole is looking a little weird" and
           | the melanoma infringing on the capillaries is roughly 4
           | months.
           | 
           | So enjoy the sun and check your skin every month.
        
         | hypeatei wrote:
         | > odd hostility between the two extremes
         | 
         | Yeah, I don't know why people care so much about what other
         | people do with their skin but I suppose that's just human
         | nature.
         | 
         | > why people seem so resistant to the idea that some sun is
         | probably beneficial
         | 
         | For me, being outdoors isn't necessarily conducive to an
         | enjoyable time. Very hostile environments like big ass roads,
         | high speed limits, and just the general vibe in the US of
         | questioning why someone could simply be existing without a goal
         | in mind (e.g. Karen's calling the cops)
        
         | rubicon33 wrote:
         | Such a great point. As usual, more nuance, and less black-and-
         | white thinking is important here. We need more analogue in this
         | life!
         | 
         | Personally my rule of thumb is:
         | 
         | Be active in the sun.
         | 
         | It's okay to get some sun but just baking under it for hours
         | isn't great. Shirt off for a run? Great. Swimming for an hour?
         | Great.
         | 
         | Be active, get some sun
        
           | klipt wrote:
           | I think it depends on your skin tone. Black people can get a
           | lot of sun without burning. White people evolved in a cloudy
           | climate and need less sun for the same health benefit (and
           | also burn very quickly in midday sun in not cloudy climates).
        
             | caeril wrote:
             | Skin tone is modifiable, within some limits.
             | 
             | If you maintain a base tan (equivalent to 2 hours in the
             | sun or 10 minutes in a "standard" tanning bed, per week),
             | the melanin is highly photoprotective for any additional UV
             | exposure.
        
           | jdietrich wrote:
           | _> It's okay to get some sun but just baking under it for
           | hours isn't great. Shirt off for a run? Great. Swimming for
           | an hour? Great._
           | 
           | That very much depends on your climate and skin type. In many
           | circumstances, that kind of casual exposure can still result
           | in dangerous levels of UV exposure.
        
           | david-gpu wrote:
           | Yeah, I'm the same way. I love going outside and getting some
           | exercise, even if it's just a long walk around the
           | neighborhood. I never get anything close to sunburn, because
           | I already have a crude sense of how long I can be out in the
           | sun depending on the season and how exposed it's going to be.
           | Sunscreen is great for those times when sunburn is likely,
           | but under most circumstances, a hat and white long sleeve
           | polyester shirts provide perfectly suitable protection for a
           | few hours outside, even for a pretty light skinned white guy
           | like me.
           | 
           | There's something about exercising outdoors that is
           | incredibly effective at lifting my mood, well beyond the
           | effect of doing the same indoors. For that reason you will
           | find me outside all year round regardless of the weather.
        
           | grecy wrote:
           | > * Shirt off for a run? Great. Swimming for an hour? Great.*
           | 
           | Tell me you don't live in Australia without telling me.
           | 
           | Doing that in Australia is basically the fast-track path to
           | skin cancer thanks to the hole in the ozone layer.
           | 
           | Going back after ~10 years away I was staggered to experience
           | the feeling of hot chilli peppers being ground into my skin
           | after standing in the sun for ~5 minutes.
           | 
           | Nowhere in Africa was like that.
        
             | jerlam wrote:
             | Australia's sun recommendations have become more nuanced,
             | taking into account skin type:
             | 
             | https://www.abc.net.au/news/2024-02-13/sun-safety-
             | position-s...
        
         | Aurornis wrote:
         | > But I don't understand why people seem so resistant to the
         | idea that some sun is probably beneficial.
         | 
         | There are some people who believe this, but Vitamin D and sun
         | exposure have been a popular topic for a very long time now.
         | It's getting harder to find people who think that avoiding all
         | sun exposure is a good idea.
         | 
         | The most confusing part appears to be the idea that wearing
         | sunscreen is equivalent to avoiding UV exposure. Sunscreen
         | reduces UV exposure, but does not completely eliminate it. This
         | misconception has produced a lot of people who think "sunscreen
         | bad" because "UV good". You can get moderate UV exposure while
         | wearing sunscreen.
        
           | klipt wrote:
           | But some people think that just popping a vitamin D pill
           | gives you all the benefits of sun exposure without the
           | downsides.
           | 
           | Research on all cause mortality disagrees. Some sun exposure
           | reduces all cause mortality even if you already take vitamin
           | D.
        
             | Aerroon wrote:
             | But what doses did they take in the research? Vitamin D RDA
             | has been increased by like 5-10x recently in some countries
             | (others are still lagging behind), because the RDA that
             | we've used for decades had a calculation error.
             | 
             | If the studies dosed vitamin D based on recommendations
             | then it shouldn't be surprising that supplementing vitamin
             | D didn't work. Considering that only a few countries have
             | updated their vitamin D RDA in the past few years, and most
             | haven't, then I think it's likely that most studies on the
             | topic will have too low of a dose of vitamin D
             | supplementation.
             | 
             | The vitamin D error:
             | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4210929/
             | 
             | ---
             | 
             | It's also possible that some of the health benefits don't
             | come from vitamin D or UV exposure, but instead from
             | something like red light exposure or some other wavelength.
             | (Red) light therapy is a popular topic for example. It's
             | mostly touted to improve skin aging and it's being studied
             | as a help with myopia in children. Does it work? No idea.
        
             | jdietrich wrote:
             | _> Research on all cause mortality disagrees. Some sun
             | exposure reduces all cause mortality even if you already
             | take vitamin D._
             | 
             | Some sun exposure is _correlated_ with lower all-cause
             | mortality. That is a very long way from establishing
             | causation, particularly considering all of the other
             | plausible explanations for that correlation.
        
             | cube2222 wrote:
             | I wonder if it's just correlation, with the actual cause of
             | both being physical activity. Physical activity likely
             | makes you go out into the sun more, and it also likely
             | reduces mortality.
             | 
             | Would be great if you provided a source so we could check
             | whether they controlled for physical activity.
        
               | maeil wrote:
               | One of the things I love most about HN - you think of a
               | hypothesis, and right after you see someone else who has
               | already posted it. Very curious about this one as well.
               | Though I don't imagine it being the "actual cause", just
               | a big cofactor. I'd still put some money on the direct
               | effect of sunlight absorption by your skin in itself
               | having additional positive benefits (in appropriate
               | doses).
        
             | addicted wrote:
             | I would be very surprised if the research you're pointing
             | to suggests causation.
             | 
             | I'm not saying causation doesn't exist. But the reason why
             | this issue is hard to resolve is precisely because
             | causation one way or another is hard to establish.
             | 
             | Causation for specific effects of Sun exposure is much
             | easier to establish (for example skin cancer due to
             | exposure, or lower depression due to exposure).
        
             | reducesuffering wrote:
             | > some people think that just popping a vitamin D pill
             | gives you all the benefits of sun exposure without the
             | downsides.
             | 
             | No one with any cursory research would still think that.
             | Nitric Oxide benefits have been known for awhile.
             | 
             | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6830553/
        
             | mcguire wrote:
             | How do you control for sun exposure versus outdoor physical
             | activity and any of the other factors?
        
           | taeric wrote:
           | I mean, I want to agree with you, but it is easy to see that
           | everyone says any tanning of your skin is indication that you
           | have skin damage. Which, frankly, feels extremely stated to
           | me.
           | 
           | Pale skin from living in a cave looks just as unhealthy as
           | leather tan skin from all day sun exposure over years.
           | Moderate tan from being outside, though? I have a hard time
           | thinking it is as dangerous as stated. Feels like saying
           | "soreness is your muscles recovering from damage and you
           | should avoid it."
        
             | vineyardmike wrote:
             | > Feels like saying "soreness is your muscles recovering
             | from damage and you should avoid it."
             | 
             | Except this is an _analogy_ not a true comparison of the
             | systems. The act of growing muscles is due to muscle damage
             | and regrowth (to really handwave), and that action causes
             | soreness. It's not cumulative damage to the muscles,
             | ideally it should heal in between. The same experience is
             | _not_ true for skin. You're not "improving the health" of
             | your skin by being tan, and we know that damage to the skin
             | is cumulative.
             | 
             | The health benefits of being in the sun seem to be a
             | combination of mental-health (sun=happy) and chemical-
             | release when skin is exposed to sun (eg vitamin D). This
             | seems more like "certain side affects of sun expose are
             | positive _to the overall body_ , despite the growing damage
             | _to the skin_ ".
        
               | taeric wrote:
               | Agreed that it is an analogy. I'll go farther and agree
               | that I could flat be wrong! :D
               | 
               | In the analogy, though, I do know people have a hard time
               | distinguishing between pain and soreness. Such that it is
               | not uncommon for people to exercise too hard and trigger
               | pain, which will slow them down. As such, I expect that
               | sun exposure is likely the same. I even agree that it is
               | probably easier to jump over any threshold that there may
               | be and to get too much sun. I have a hard time thinking
               | any darkening of skin is a sign of damage, though.
               | 
               | I also think it is tough to distinguish between damage
               | versus wear. Which, is probably just my not liking the
               | language of "damage" here. Do we say that guitar players
               | have damaged their skin to build calloused finger tips?
               | (Genuine question.)
        
           | jordanb wrote:
           | > It's getting harder to find people who think that avoiding
           | all sun exposure is a good idea.
           | 
           | Not in Asia.
        
         | dundercoder wrote:
         | Personally, I think it's easier to be extreme than balanced.
         | Like a see-saw (or teeter totter depending on where you are)
         | it's way easier to sit on one end or the other. To try to stand
         | on the middle and balance is hard.
         | 
         | A friend of mine met Patrick Moore, former President of
         | Greenpeace, and asked Moore why he started supporting nuclear
         | power, he told him essentially "It's easier to be against
         | everything than to be for something."
        
           | deepsun wrote:
           | I think it's the other way around. It's definitely easier to
           | walk around under some sun shopping groceries and occasional
           | brunch, than go to extremes and hide under some cover all the
           | time, or sunbathing the whole day.
        
             | loco5niner wrote:
             | Easiest just to not get out of bed or go straight to a
             | couch, and drive occasionally to pizza hut.
        
               | vineyardmike wrote:
               | No because most people have jobs and limited money.
               | 
               | It's easier _in most people's existing lives_ to avoid
               | taking extreme health measures. Most people don't go to a
               | gym or exercise for the suggested min /day, but most
               | people go to their job instead of staying in bed.
        
           | ZeroGravitas wrote:
           | Patrick Moore is a professional climate change denier now
           | (and for a few decades) so maybe not the best example.
           | 
           | https://www.desmog.com/patrick-moore/
        
             | WheatMillington wrote:
             | You're literally committing the sin described in the parent
             | comment - refusing to acknowledge nuance.
        
         | kome wrote:
         | I must be living under a rock, but at least where I come from,
         | it is common sense that _some_ sun exposure is good. I 've
         | never heard of anyone saying that the sun should be avoided at
         | all costs, it's weird. but then you find people on the internet
         | who claim that cats (of all animals!) should stay at home at
         | all costs. that's also weird. But these are mostly internet
         | people, I've never found one in real life...
         | 
         | Maybe the general problem is that the internet has very vocal
         | minorities.
        
           | weaksauce wrote:
           | > but then you find people on the internet who claim that
           | cats (of all animals!) should stay at home at all costs.
           | 
           | vocal minorities such as the aspca?
           | 
           | https://www.aspca.org/pet-care/cat-care/general-cat-care
           | 
           | > Please keep your cat indoors. Outdoor cats do not live as
           | long as indoor cats. Outdoor cats are at risk of trauma from
           | cars, or from fights with other cats, raccoons and free-
           | roaming dogs. Coyotes are known to eat cats. Outdoor cats are
           | more likely to become infested with fleas or ticks, as well
           | as contract infectious diseases.
        
         | sholladay wrote:
         | > I don't understand why people seem so resistant to the idea
         | that some sun is probably beneficial.
         | 
         | A cynical take would be that it's because there is no profit in
         | sun exposure. Even places that would theoretically have a
         | motivation to promote sun exposure, such as beaches and outdoor
         | restaurants, have goals that are perfectly compatible with
         | umbrellas and sunscreen and hats and sunglasses, etc. In fact,
         | those are just complimentary sales for them. Tanning salons
         | come to mind, but the sun is their biggest competitor.
         | 
         | > "basking in the sun" is almost certainly taking it too far
         | 
         | Plenty of animals sunbathe, though, not just humans. Lots of
         | reptiles, of course, but my dog also does it every chance she
         | can get.
        
           | taeric wrote:
           | Amusingly, my dogs specifically will only sit in the shade
           | outside. Same for the various snakes and other animals in the
           | yard. Hard to know if that is avoiding sun, or avoiding
           | predator birds, though. My guess would be the birds are far
           | more of a concern for the animals.
        
             | maipen wrote:
             | My dogs and cats love sunbathing.
             | 
             | But they intercalate between shade and sun all day.
             | 
             | It's about balance, that's what I learned from observing
             | them.
        
           | mcswell wrote:
           | My cat says sunbathing on the back of his (it's our, but I
           | don't tell him that) couch is how he's reached his advanced
           | age. He'll be 22 in a couple weeks.
        
         | alyandon wrote:
         | My older parents here in the southern US are both dealing with
         | skin cancer of various forms (melanoma and squamous cell
         | carcinoma) because of accumulated sun exposure from when they
         | were younger. Neither one of them were tanning fanatics/sun
         | bunnies/whatever but they would very occasionally get mild
         | sunburns from working outside without adequate protection.
         | 
         | I myself try to avoid prolonged direct exposure to the sun as a
         | matter of principle to try and avoid having to deal with that
         | stuff when I'm their age. If I'm going to be out in direct
         | sunlight for a prolonged period of time, I'm going to be
         | wearing sunscreen and a hat.
         | 
         | It's really hard to know where to draw the line between "too
         | much sun" vs "no sun".
        
           | bityard wrote:
           | > because of accumulated sun exposure from when they were
           | younger.
           | 
           | I don't think this gets enough attention.
           | 
           | It's anecdata, so grain of salt and all of that, but one day
           | when I was around 8 or 10 years old, I spent essentially the
           | entirety of a bright summer day playing on the beach near a
           | relative's cabin. It was the longest I had ever spent
           | continuously in the sun up until that point. No one warned me
           | to take extended breaks in the shade, or suggested sunscreen.
           | I don't think I even heard about sunscreen at that point. At
           | the end of the day, almost all of my skin was bright red and
           | extremely painful to the touch. All of the adults thought it
           | was funny. I was in excruciating pain for the next 48 hours.
           | 
           | It's not that the adults (parents, aunts, uncles, etc)
           | weren't caring, they just seemed to think that painful
           | sunburns were just a normal summer thing. Maybe even a right
           | of passage.
           | 
           | I was _much_ more careful about sun exposure after that
           | experience.
           | 
           | Anyway, fast forward a couple of decades and now I have
           | damaged skin everywhere that sunburn happened. Lots of moles
           | on the tops of my arms, shoulders, and back (virtually none
           | on the bottom), scar tissue from where injuries never healed
           | properly, etc. Skin cancer is very likely in my future.
           | 
           | I have two kids and they whine and groan and complain when I
           | berate them about not wearing sunscreen or taking shade
           | breaks. Oh well.
        
             | alyandon wrote:
             | We can only strive to do better for our children than our
             | parents did for us.
        
           | GeoAtreides wrote:
           | >occasionally get mild sunburns
           | 
           | >It's really hard to know where to draw the line between "too
           | much sun" vs "no sun".
           | 
           | Apparently it's not that hard, occasionally mild sunburns is
           | right out; seems like we have a provisional maximal limit to
           | sun exposure.
        
             | alyandon wrote:
             | I really think genetics has to be a factor as well.
        
         | falcolas wrote:
         | > But I don't understand why people seem so resistant to the
         | idea that some sun is probably beneficial.
         | 
         | The sun ages your skin. It makes you look older. I've known
         | people in their 40's who have avoided sun who look like they're
         | in their late 20's. Their skin is supple, has few wrinkles, and
         | generally looks healthy. My friend is my age, his wife is 10
         | years older than he. She legitimately looks a good 10 years
         | younger than him thanks to intentionally avoiding the sun
         | throughout her life.
         | 
         | I, in contrast, look my age (40's as well), because I've spent
         | a reasonable amount of my life outside. Chores, being raised
         | with an attitude of "don't come back inside until dinnertime",
         | and swimming competitively in the summer. My skin doesn't heal
         | as well, it's less supple (sub-skin features show through more
         | harshly than they used to), and I have a fair share of wrinkles
         | around my eyes and corners of my mouth (charitably referred to
         | as laugh lines).
         | 
         | And then there's the extreme sunbathers and outdoor laborers
         | who look like they're in their 70's at 40; who have already had
         | potential cancerous spots on their skin removed.
         | 
         | It's simply one of those things where even moderate exposure
         | can do demonstrable damage to your skin. And if not treated
         | quickly, the cancer sun exposure causes can straight up kill
         | you.
         | 
         | Finding out that it may also have positive benefits feels
         | weird. It feels like learning that regular exposure to acid has
         | long term health benefits.
        
           | debatem1 wrote:
           | Isn't this basically also true of exercise? Running is great
           | for you, but it puts a strain on the cartilage in your joints
           | which will become slower to heal and faster to harm over
           | time. Still, most people would rather have great pulmonary
           | health and a knee replacement by 70 than nice knees and a bad
           | ticker.
           | 
           | Maybe a similar tradeoff here.
        
           | dullcrisp wrote:
           | > Finding out that it may also have positive benefits feels
           | weird. It feels like learning that regular exposure to acid
           | has long term health benefits.
           | 
           | How can that be weird? Just about everything can kill you in
           | large quantities but some things are still good for you in
           | the right doses. I'm pretty sure your proteins are made out
           | of acids.
        
           | DataDive wrote:
           | lets use common sense a bit, humans have evolved while being
           | in the sun, constantly, their skin darkened to protect them
           | 
           | as humans moved northward, the exposure to sun was so
           | important that even their skin lost it protective
           | pigmentation to allow more sun to reach the body
           | 
           | we are not even remotely close to understanding all the
           | beneficial processes that take place when the sun hits skin
           | 
           | thinking that exposure to sun is like exposure to acid shows
           | a complete disconnect from reality,
           | 
           | I would urge you to read up on this a lot more - you will
           | find that people who spend time outdoors in the sun are
           | healthier, happier, and live longer. Their outcomes when
           | facing all kinds of cancers are far, far better.
        
         | xkcd-sucks wrote:
         | Maybe "growth factor" as in "sunlight is a growth factor" is
         | appropriately neutral?
         | 
         | Case in point, melanin synthesis and libido systems are
         | related: There's a drug "bremelanotide" and by now probably
         | some others, injectable melanocortin receptor agonists
         | originally marketed for whole-body skin tanning. But actually
         | it's marketed for libido enhancement and in the process it
         | turned out that most MC receptor subtypes regulate
         | mood/cognition more than skin color
         | 
         | TL;DR, there's evidence to suggest - in humans - that sunlight
         | exposure makes people want to bone. Assuming the sunlight ->
         | MCR activation assumption is true lol
        
       | kkoncevicius wrote:
       | Anecdotal, but the parts of my skin that see more sun exposure
       | (forearms) look healthier compared with parts that are more
       | covered (upper arms). I wonder if maybe gradual sun exposure
       | starting from spring and increasing towards the summer is
       | healthier compared to sudden intense tanning of the area that is
       | otherwise constantly covered by clothes.
        
         | matsemann wrote:
         | That can be for other reasons, though. Like one's upper arm is
         | often looser or have more fat below the skin, making it a
         | different texture than the more taught lower arms.
        
         | IshKebab wrote:
         | Sunlight can definitely clear up some skin conditions like
         | eczema. I don't know about making skin healthier in general
         | though. It 100% causes aging in skin though so any "healthier"
         | skin you get will be totally wiped out by the wrinkly mess it
         | becomes in your 40s.
         | 
         | The message we should send kids is not "wear suncream; it
         | prevents cancer" it's "wear suncream; it prevents wrinkles".
         | Surprising how many people don't even know that.
         | 
         | There's a famous photo that demonstrates it very obviously:
         | 
         | https://metro.co.uk/2018/01/28/photo-truck-driver-shows-28-y...
         | 
         | Which side would you prefer?
        
           | kkoncevicius wrote:
           | I am suspicious of that driver effect being caused solely by
           | sun exposure. If that were the case we would see the same
           | effect in all drivers.
        
             | whyoh wrote:
             | It's possible that he was driving with the open window or
             | that the window in his truck wasn't blocking much UVA.
        
           | jacobsenscott wrote:
           | It isn't a wrinkly mess, it's character.
        
         | jajko wrote:
         | Lets see when you are older. The difference (number of moles,
         | overall skin age) should be visible on most skin types
        
       | runjake wrote:
       | tl;dr: _Some_ sun is good. _No_ sun, or _too much_ sun, is bad.
       | 
       | This advice will probably never change, regardless of qualified
       | studies.
        
       | kerkeslager wrote:
       | Sun exposure has been inversely correlated with depression, and
       | frankly depression by itself is worse than all the negative
       | effects of UV I'm aware of combined.
        
         | jdietrich wrote:
         | There are an awful lot of possible causal relationships that
         | could explain that correlation. On the face of it,
         | relationships like "depressed people can't face going outside"
         | or "people who are too immobile to leave the house get
         | depressed" seem far more plausible and powerful than "UV
         | exposure reduces the risk of depression through some yet-
         | unknown mechanism".
        
           | kerkeslager wrote:
           | Based on what my previous post said, sure, but there are more
           | reasons to believe that sunlight is inversely causal in
           | depression than I stated. I'm hesitant to dig up the research
           | I looked through though, because if I recall correctly, the
           | research really brings up more questions than it answers.
           | 
           | In a more general sense, I agree that more research is
           | needed, but with this and many other facts about our brains
           | and bodies, I'm becoming more cynical about the possibility
           | that the research will be performed in our lifetimes. There's
           | simply too much we don't know and too little funding and too
           | few researchers to find conclusive answers for all of it.
           | People have depression now, and when the risks of the
           | "treatment" are much lower than the risk of the disease, I
           | think it makes sense to self experiment and see if the
           | treatment helps _you_. Beyond the studies, there seems to be
           | some anecdotal evidence that sunlight does help depression,
           | and I tend to think depression has worse risks than
           | (moderate) sun exposure.
           | 
           | Two notes:
           | 
           | 1. From a scientific perspective, one of the problems with
           | anecdotal evidence is that it might be the result of placebo
           | effect, which a well-crafted scientific study would
           | eliminate. But from a medical perspective: who cares? If
           | sunlight improves your depression via the placebo effect,
           | well, your depression has been improved.
           | 
           | 2. To be clear about a caveat: I'm _not_ saying go out and
           | self-experiment every home remedy you can find. The bit I
           | said about  "when the risks of the 'treatment' are much lower
           | than the risk of the disease" is important. Powerful drugs
           | like ivermectin have dangerous side effects, and trying
           | different supplements can become costly even when those
           | supplements contain what they claim and have lower risks.
        
       | dukeofdoom wrote:
       | I think you can look into what humans desire for their ideal
       | vacation places. The subconscious guides the conscious. This
       | usually involves a sunny beach and water. Or at least a pool.
       | Tropical fruits for breakfast and eggs is kind of a hotel
       | standard for a reason too. Good nutrition and an a fun adventures
       | day. Kind of polar opposite of dark depression.
       | 
       | Not too soud woowoo, but people with good vibes and sunny energy
       | is what you should seek too.
        
       | m3kw9 wrote:
       | too much is bad, too little is bad, these doctors are not helping
       | very much.
        
       | Kalanos wrote:
       | Perhaps because bacteria have no nucleus to protect their DNA and
       | less DNA-damage repair mechanisms?
        
       | slothtrop wrote:
       | Would note that full-spectrum light penetrates thin layers of
       | clothing such that you can still yield some benefits being
       | outside fully clothed, with mitigated risk. Also, even with
       | sunscreen you'll synthesize some vitamin D. You'd have to really
       | lay it on thick over all of your body to meaningfully prevent
       | that, and it only lasts for a limited time anyway.
       | 
       | On sunscreen there's talk about non-mineral ones having compounds
       | that traverse the blood-brain barrier, but not much to suggest it
       | can be dangerous. Since mineral sunscreens are oilier, my
       | approach is to slather that type on my body, and use an
       | alternative for my face using a light amount.
        
       | ortusdux wrote:
       | Reminds me of people paying for radon exposure:
       | 
       | https://www.mdpi.com/1422-0067/22/1/316
       | 
       | https://www.youtube.com/watch?v=zZkusjDFlS0
        
       | Aurornis wrote:
       | Reducing everything to "good for you" or "bad for you" is the
       | media's favorite game. Nuance is hard, so reducing complex topics
       | to extreme statements makes them easy to digest. It also creates
       | an opportunity for them to manufacture debate whenever a new
       | piece of information comes out that doesn't fit into their self-
       | created bipolar conception.
       | 
       | As always with these topics: UV exposure isn't something that can
       | be reduced to "good" or "bad". Both extremes of complete UV
       | avoidance and excess UV exposure have consequences.
       | 
       | What people frequently miss on this topic is that sunscreen isn't
       | a 100% effective UV blocker. People who cover themselves in
       | sunscreen and then spend significant time outside are receiving
       | some UV exposure. This fact is lost on many people, which is why
       | skin cancer rates can be higher in people who use a lot of
       | sunscreen. Sunscreen enables people to spend more time in the sun
       | and be less covered, which can paradoxically lead people to get
       | more UV exposure over more of their body than, for example, the
       | person who works outside M-F but covers up with long sleeves,
       | hats, and pants (like you will see in yard work crews,
       | construction workers, and other trades).
       | 
       | These headlines are difficult because some people read them as an
       | invitation to stop using sunscreen but continue their old habits,
       | pushing their UV exposure deep into the high risk region of the
       | benefit-reward curves.
        
         | AlexandrB wrote:
         | > UV exposure isn't something that can be reduced to "good" or
         | "bad".
         | 
         | Indeed this is true about almost anything we _commonly_ put
         | into our body: fat, protein, carbs, even water. But it gets a
         | lot more clicks to claim that something is either always good
         | or always bad.
        
       | sowut wrote:
       | there's a popular trend that has been gaining momentum over
       | decades that has people so disconnected from reality that they
       | think a pill can replace proper diet, exercise, and in this case,
       | the sun.
       | 
       | there is an obesity epidemic in this country at the root of many
       | ailments (inflammation is the root of many diseases) and you have
       | politicians pitching policies about bringing the cost of "drugs"
       | down to treat these ailments but we have no mainstream leaders
       | with mainstream policies advocating for health and fitness to fix
       | the root issue.
       | 
       | we're going in the wrong direction and something has to change.
        
         | reducesuffering wrote:
         | > advocating for health and fitness to fix the root issue.
         | 
         | Do you know any GP's / doctors? They'll all tell you that's the
         | first line they repeatedly recommend to their patients. It
         | barely works, because mostly that has to come from intrinsic
         | motivation. And then they proceed to the "well if they won't
         | eat healthier and exercise, what else is going to do something
         | for them..."
        
           | sowut wrote:
           | "we have no mainstream leaders with mainstream policies
           | advocating for health and fitness to fix the root issue"
        
       | coppsilgold wrote:
       | From the point of view of evolution the sun is a fact of the
       | universe and it would have adapted numerous processes to rely on
       | its presence. That does not mean the sun is safe however. Skin
       | color variance so closely tied to geographic location indicates
       | that there is a very delicate balance there.
        
       | blueridge wrote:
       | I'll take the UV rays over a bunch of smelly, synthetic goop all
       | over my skin. I also see people go from not seeing the sun in
       | months to full, 1pm exposure for hours, then they get roasted,
       | then they're in pain, then it takes weeks to heal, then they do
       | it again. Or they'll start slathering on an absurd amount of
       | sunscreen, the summer months go by, and they look just as sick
       | and pasty and unhealthy as they did last year, as if they never
       | went outside.
       | 
       | You've got to build intuition around how to get sun: what's your
       | current skin tone, how much sun you've had recently, what it
       | feels like to get an appropriate amount of sun vs. get burnt, the
       | time of day, elevation considerations, whether you're going to be
       | in the sun again tomorrow or all week after a lot of exposure
       | today, if you're getting more direct sun on key areas like your
       | neck and nose and ears, or whether you've got full body exposure.
       | The more time in the sun, the more you understand how to behave,
       | how to protect yourself, how to get what you need to feel good.
       | 
       | Most people pay no attention to how they feel day-to-day. They
       | never learn what it feels like to eat a nutritiously dense meal,
       | or what being fit feels like over the long term. It's the same
       | with sun exposure: if you don't pay attention, you'll never
       | learn.
        
         | maipen wrote:
         | You make a good point.
         | 
         | I did see a pattern in my friend circle of those that got sun
         | burn and those who don't.
         | 
         | Skin color and sun exposure habits play a big role.
         | 
         | The paler you are the more disciplined you need to be in
         | regards to sun exposure, in order for your skin to adapt and
         | build tolerance
        
           | lilyball wrote:
           | You don't "build tolerance" to UV. Developing a tan will help
           | avoid getting sunburn in the future, but it does nothing at
           | all to reduce your risk of skin cancer. Sunscreen doesn't
           | just stop sunburn, it also prevents cancer.
        
             | hgomersall wrote:
             | I suppose black people just have a full body tan for the
             | evolved aesthetic?
             | 
             | You're going to have to provide some evidence if you're
             | suggesting a tan has no protective effect against sun
             | damage.
        
         | dgan wrote:
         | >> I'll take the UV rays over a bunch of smelly, synthetic goop
         | all over my skin
         | 
         | You are clearly not allergic to the sunlight / UV, aren't you?
         | Because i am, and definitely taking synthetic goop over red
         | rash all over the exposed body parts
        
       | Aerroon wrote:
       | It might not be UV exposure that helps though. The sun has a
       | bunch of other wavelengths of light as well. There's red light
       | therapy that might have positive health effects and you certainly
       | get that from the sun as well.
        
       | zarzavat wrote:
       | Let's imagine that exposure to UV gives you more statistical QALY
       | than melanoma and skin aging remove. I believe this is _false_
       | but let's imagine it's true.
       | 
       | Okay but there's many other things that also give you more QALY,
       | things that don't increase your risk of a horrible disease or
       | looking like a prune when you're 40. Maybe we should do those
       | things _first_ and only come back to double-edged life extension
       | techniques when we've completed all the benign techniques.
       | 
       | After all, caloric restriction also increases lifespan, but the
       | cost is so high in terms of life enjoyment that few would be
       | tempted. There's more to life than time spent living.
        
         | ziddoap wrote:
         | "QALY" may not be obscure to you, but this is the first time
         | I've ever seen it. It's always appreciated when you can spell
         | out an acronym for other readers who maybe aren't as familiar
         | with a topic as you are.
         | 
         | Given the context, Google leads me to believe:
         | 
         | QALY = Quality-adjusted life year
        
       | mcguire wrote:
       | Discussion of the actual paper:
       | https://news.ycombinator.com/item?id=41302103
        
       | Ekaros wrote:
       | For average office worker, during regular week it probably makes
       | no sense to avoid exposure. On other hand sun bathing or tanning
       | is probably not good for you either.
       | 
       | Sensible moderation makes most sense to me. If you are extended
       | periods in sun cover yourself or use protection. But no
       | particular need to avoid it in short periods.
        
       | mint2 wrote:
       | As I posted in the dupe of this -
       | 
       | this article is specifically about regions in "low" UV latitudes,
       | with the actual subject being from the UK. Accounting for UV
       | intensity of your home country is crucial.
       | 
       | Don't just go out and frolic without precautions just because a
       | study from the UK found sun exposure was good. Their sunlight
       | isn't built the same.
       | 
       | Mid day UV index in SF is 9 as I type. Compare what the paper
       | says about the UK UV index:
       | 
       | " The UV index [in the uk], which measures the erythemal
       | intensity of sunlight, rarely exceeds 6 (where 3-5 is classified
       | as moderate and 6-7 high)"
       | 
       | Make good decisions people! I got some sun when the UV was 2
       | early in the early morning. Now it's 9 at midday. All sun is not
       | equal.
        
         | adamc wrote:
         | Good point. UV in Austin, TX today is 10.6.
        
           | teekert wrote:
           | Anecdotally, I'm from across the North Sea where this study
           | was taken. I hardly ever use sunscreen. I went to a
           | conference in Galveston Tx, walked around for a part of the
           | afternoon, the next 4 days I was peeling the skin of my
           | forehead and nose... it was painful.
        
           | Kon-Peki wrote:
           | Yes but... not for the whole day. You can still get some sun
           | in the morning and evening when the UV index is a lot more
           | reasonable. Clearly not ideal but, well, that's where you
           | live.
           | 
           | I personally am looking forward to when I am able to be a
           | snowbird. Summers in the northern US, winters in the south.
           | It's the best of both worlds.
           | 
           | A few years ago, we met up with some friends from Houston at
           | a summer vacation rental up in the Traverse City Michigan
           | area. Their kids couldn't get over how late sunsets were. It
           | really messed with their heads for the first few days. But
           | when you have so so much daylight, you don't worry about
           | spending a few hours indoors when the sun is most intense -
           | you aren't wasting any of your precious vacation time.
           | 
           | And then in winter, walking along the ocean on the Gulf Coast
           | in January with only a long-sleeved shirt. For a few hours
           | most days you can get away with a T-shirt (or no shirt).
           | Glorious.
        
             | adamc wrote:
             | Given the heat, you basically need to start your walk or
             | whatever before 8am. Visited my brother in Michigan earlier
             | this summer; it was lovely. But I grew up in the north.
             | Winters were not lovely.
        
       | arijun wrote:
       | I think it's pretty obvious from our evolution that we need some
       | UV but not too much. In Africa, where we got a lot of sun, we
       | evolved darker skin to prevent damage, but in the more norther
       | latitudes, our skin tones lightened to take advantage of the
       | otherwise insufficient sunlight.
       | 
       | I feel like a good rule of thumb would be, if you're tanning,
       | your body thinks you're getting too much sun exposure for your
       | current skin color.
        
       | complianceowl wrote:
       | Follooooooow....follow the sunnnnnnnn
        
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