Exposure to the Sun's UV radiation may be good for you

https://www.economist.com/science-and-technology/2024/08/12/exposure-to-the-suns-uv-radiation-may-be-good-for-you

by beefman • 2 years ago

167 194 2 years ago

beefman• 2 years ago

Hendrikto• 2 years ago

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• 2 years ago

So why can't we just eat more Vitamin D supplements?

davidcollantes• 2 years ago

The sunlight is free. :-)

hollerith2• 2 years ago

There are 4 beneficial effects of sunlight I know of that have nothing to do with vitamin D.

Etheryte• 2 years ago

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.

_bin_• 2 years ago

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• 2 years ago

In short, because the body and the mind is a very complex system.

Hnrobert42• 2 years ago

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• 2 years ago

because its a reductionist view of the value of sunlight exposure

gruez• 2 years ago

They also point to nitric oxide, a potent blood-vessel widener capable of reducing the risk of cardiovascular disease.

pmahoney• 2 years ago

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/

jmward012• 2 years ago

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.

cpncrunch5• 2 years ago

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.

kragen• 2 years ago

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• 2 years ago

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/

jmward012• 2 years ago

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• 2 years ago

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.

MrBuddyCasino2• 2 years ago

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 naïvely is unadvisable.

colechristensen• 2 years ago

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• 2 years ago

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.

matsemann2• 2 years ago

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.

Bjorkbat• 2 years ago

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.

klipt3• 2 years ago

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• 2 years ago

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• 2 years ago

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• 2 years ago

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• 2 years ago

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.

lxgr2• 2 years ago

Most of which are in turn influencing biochemical processes in an organism, so I'd say the point still stands.

cpncrunch5• 2 years ago

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• 2 years ago

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...

lxgr2• 2 years ago

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• 2 years ago

"Avoiding Sun as Dangerous as Smoking"

https://www.medscape.com/viewarticle/860805?form=fpf

the__alchemist2• 2 years ago

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• 2 years ago

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• 2 years ago

Ben Franklin said about the same of older women!

https://en.wikipedia.org/wiki/Advice_to_a_Friend_on_Choosing...

slothtrop3• 2 years ago

Isn't sunscreen use enough?

the__alchemist2• 2 years ago

It can be.

lucius_verus• 2 years ago

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.

qingcharles2• 2 years ago

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.

trallnag2• 2 years ago

10 years, how?

JoshTko• 2 years ago

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• 2 years ago

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• 2 years ago

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.

mint22• 2 years ago

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• 2 years ago

Genetics would have adapted if it affected reproductive fitness. But skin cancer tends to develop past reproductive age.

consteval9• 2 years ago

I've started to ignore studies these days that contradict how most humans would have lived, for most of humanity

This is probably one of the worse heuristics I've ever heard.

Humans throughout humanity have lived awful lives full of disease, death, and misery. It used to be common for a woman to have 10 kids and maybe 2-3 would make it to adulthood.

The only reason you even have the ability to take such an obviously wrong position is BECAUSE of the very things you "ignore".

troymc• 2 years ago

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• 2 years ago

• Public health messaging on sunlight exposure may need reconsideration.

no kidding

taeric6• 2 years ago

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. :(

tossandthrow2• 2 years ago

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.

taeric6• 2 years ago

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.

AlexandrB2• 2 years ago

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• 2 years ago

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• 2 years ago

And the fact that general medical advice is often geared towards the common denominator. Folks who are not great an nuance

sherburt3• 2 years ago

Same thing with exposure to bacteria, too much and you get the bubonic plague, too little you get autoimmune disorders. Moderation is key.

quesera• 2 years ago

FWIW, this is overstated to the point of inaccuracy.

Bubonic plague is caused by Yersinia pestis only, regardless of exposure level.

Reduced exposure to common beneficial bacteria in young children might cause a mild increase in susceptibility to colds, allergies, asthma, eczema.

Your examples have nothing to do with moderation.

simonbarker87• 2 years ago

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.

addicted2• 2 years ago

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.

caeril2• 2 years ago

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.

consteval9• 2 years ago

You should always wear sunscreen. You get all the benefits of the sun, including mental health, with sunscreen.

It's not magic. You're still in the sun. You're not inside.

hypeatei• 2 years ago

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• 2 years ago

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

klipt3• 2 years ago

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).

jdietrich3• 2 years ago

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• 2 years ago

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• 2 years ago

* 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.

Aurornis3• 2 years ago

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.

klipt3• 2 years ago

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.

taeric6• 2 years ago

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."

jordanb• 2 years ago

It’s getting harder to find people who think that avoiding all sun exposure is a good idea.

Not in Asia.

devilbunny• 2 years ago

You can get moderate UV exposure while wearing sunscreen.

Indeed, some of us count on it. My wife loves the beach/pool. So we take a fair number of vacations like that.

I’m a natural redhead. Sun and I are strangers.

But, sunscreened-up, and under an umbrella, I can sit outside and enjoy tropical drinks and reading a book. And still get what passes as a tan for me.

dundercoder• 2 years ago

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• 2 years ago

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.

ZeroGravitas• 2 years ago

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/

kome• 2 years ago

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• 2 years ago

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.

consteval9• 2 years ago

I've never heard of anyone saying that the sun should be avoided at all costs, it's weird

Yeah that's because nobody says that.

They say, following the advice of every medical association ever, that you should wear sunscreen,

Somehow, people interpret "sunscreen" as "no sun". Not the same thing. You still get Vitamin D and all the benefits of the sun with sunscreen because you are, in fact, in the sun.

bal00ns• 2 years ago

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...

I’m one of these people. I swear I’m not just an internet person. Most of my friends who own cats also have these views as well.

Cats are incredibly efficient killers and live a considerably shorter life when given unsupervised access outdoors. Just because it’s natural for them doesn’t mean it’s good for them or their environment. Cats can live perfectly happy lives indoors, if taken care of properly. This isn’t weird. What’s weird is what’s normal.

sholladay2• 2 years ago

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.

taeric6• 2 years ago

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.

mcswell• 2 years ago

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.

consteval9• 2 years ago

I'm no scientist, but I think scaly skin and fur MIGHT be different than human skin.

alyandon3• 2 years ago

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• 2 years ago

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.

GeoAtreides• 2 years ago

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.

falcolas• 2 years ago

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• 2 years ago

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• 2 years ago

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.

DataDive2• 2 years ago

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.

cassianoleal• 2 years ago

I, on the other hand, am 43 and it's not rare for people to think I'm under 30.

I was born and raised in the south of Brazil, an area that was known as one of the worst affected by the ozone layer "hole" in the 90s. I used to spend 3 months per year at the beach, under that extreme sun. The rest of the year was also very sun-rich and a lot of it spent outside. I had my skin burned many times.

I know a lot of other people who had similar upbringings and also look a lot younger than their ages.

xkcd-sucks• 2 years ago

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

shirro2• 2 years ago

It is a tough discussion as with anything nuanced online.

The negative consequences of UV exposure are compelling and very visible both with aging and skin cancer.

It would be irresponsible to promote uv exposure but also factually it is an effective treatment for some conditions in some people and possibly has less obvious benefit to others. UV exposure does things to our immune system that can't be replicated by vitamin D supplements. As crazy as it may seem, occasionally "basking in the sun" might be reasonably cheap, accessible and effective disease management for some very specific cases even if it doesn't seem very wise to say so and risk the accusatory finger pointing.

kkoncevicius2• 2 years ago

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.

matsemann2• 2 years ago

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.

IshKebab3• 2 years ago

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?

kkoncevicius2• 2 years ago

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.

jacobsenscott• 2 years ago

It isn't a wrinkly mess, it's character.

jajko• 2 years ago

Lets see when you are older. The difference (number of moles, overall skin age) should be visible on most skin types

runjake• 2 years ago

tl;dr: Some sun is good. No sun, or too much sun, is bad.

This advice will probably never change, regardless of qualified studies.

kerkeslager2• 2 years ago

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.

jdietrich3• 2 years ago

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".

kerkeslager2• 2 years ago

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• 2 years ago

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• 2 years ago

too much is bad, too little is bad, these doctors are not helping very much.

Kalanos• 2 years ago

Perhaps because bacteria have no nucleus to protect their DNA and less DNA-damage repair mechanisms?

slothtrop3• 2 years ago

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• 2 years ago

Reminds me of people paying for radon exposure:

https://www.mdpi.com/1422-0067/22/1/316

https://www.youtube.com/watch?v=zZkusjDFlS0

Aurornis3• 2 years ago

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.

AlexandrB2• 2 years ago

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.

sowut4• 2 years ago

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.

reducesuffering2• 2 years ago

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..."

sowut4• 2 years ago

"we have no mainstream leaders with mainstream policies advocating for health and fitness to fix the root issue"

trallnag2• 2 years ago

Sounds like Steve Jobs eating carrots to beat cancer

sowut4• 2 years ago

or, you know, sounds like this whole thread is full of people who are confused as to why you can't just take vitamin d supplements and hide from the sun

coppsilgold• 2 years ago

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• 2 years ago

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.

maipen2• 2 years ago

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

lilyball2• 2 years ago

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.

dgan• 2 years ago

> 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

Krssst• 2 years ago

I'll take the UV rays over a bunch of smelly, synthetic goop all over my skin.

There are portable sun umbrellas that allow you to protect your skin without sunscreen. But I doubt they'll cover the entire body, though it should be enough for the head and the arms. And I am not sure if the reflected rays of the sun against various surfaces (windows, cars...) are not dangerous.

Aerroon2• 2 years ago

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.

zarzavat2• 2 years ago

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• 2 years ago

"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

zarzavat2• 2 years ago

Yes, the idea is that extending life is important but not every year of life is equivalent. If you spend a year bedridden that’s not as good as a year housebound, which is not as good as a year when you are in perfect health.

So when people measure the value of interventions it’s measured in QALY.

The downside is that it’s subjective.

mcguire2• 2 years ago

Discussion of the actual paper: https://news.ycombinator.com/item?id=41302103

Ekaros• 2 years ago

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.

mint22• 2 years ago

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.

adamc2• 2 years ago

Good point. UV in Austin, TX today is 10.6.

teekert• 2 years ago

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• 2 years ago

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.

arijun• 2 years ago

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• 2 years ago

♫♫ Follooooooow....follow the sunnnnnnnn ♫♫

abeppu• 2 years ago

Someone living in Truro, for example, in the south of Britain, would on average experience about 25% more solar shortwave radiation (a measure that includes UV, visible and some infrared light) in a year than someone living in Glasgow or Edinburgh, which are much further north.

I'm surprised that the difference is that big, given that the latitude difference between these is actually relatively small. If this difference is correct, is it really just due to the north/south distance, or is this more about weather differences, or is there some other non-obvious factor?

Exposure to the Sun's UV radiation may be good for you

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