[HN Gopher] Time to sunburn
___________________________________________________________________
Time to sunburn
Author : epiteton
Score : 75 points
Date : 2021-06-15 16:43 UTC (6 hours ago)
(HTM) web link (deepnote.com)
(TXT) w3m dump (deepnote.com)
| Taniwha wrote:
| Dangerous! does not seem to take the southern hemisphere ozone
| hole into account
| bradgranath wrote:
| We've destroyed the atmosphere on this planet in so many ways to
| the point that we should all just be wearing spacesuit all the
| time.
| 11235813213455 wrote:
| If people could avoid as much as possible suncreams, that'd be
| great (using natural protections, clothes, ...), just for their
| plastic wrapping at least, I know some are said to be
| environment-safe, but still
| AceJohnny2 wrote:
| Where are you that suncream packaging is the most concerning
| litter?
| thehappypm wrote:
| I understand this sentiment, but preventing cancer and pain is
| a pretty good reason to generate some trash, in my experience.
| there's a lot of truly wasteful plastic use out there, but I
| would not say this is one of them.
| hprotagonist wrote:
| I _hate_ sunscreen. It's unpleasant to wear. I always do, but
| it's not my favorite part of summer by far.
|
| This year i am experimenting with rashguards and big stupid
| floppy hats.
| mrfusion wrote:
| I got a water based one which doesn't feel bad but then I'm not
| sure if it stays in when I sweat.
| ReptileMan wrote:
| Unless you are a field worker, fisherman, truck driver or some
| other similar professions, I think you can ignore the
| sunscreen. You are very rarely forced to be exposed to the
| harshest sun for prolonged periods of time.
| hasbot wrote:
| You're overlooking outdoor activities like biking,
| snowboarding, and sailing.
| ahelwer wrote:
| Hats are good, as is sun-protective clothing in general. There
| are a number of companies providing some kind of ultra-thin
| sun-protective hoodie which is surprisingly comfortable to wear
| even in hot temperatures. I have a few echo hoodies from
| outdoor research.
| m-p-3 wrote:
| There are sun sleeves which you can wear with your casual
| clothes too.
| clint wrote:
| Some sunscreen is and it's mostly the cheap drugstore junk you
| see in almost all retail settings.
|
| There are plenty of sunscreens out there which are not greasy
| and don't stink and you won't notice once you apply it.
| silicon2401 wrote:
| Buy UPF shirts from Patagonia, a relatively environmentally-
| friendly company. I never go out in the summer without UPF-50
| long sleeve shirts, never have an issue with tanning let alone
| burning, and always feel perfectly comfortable as I don't have
| to apply or remove as much sunscreen.
| hprotagonist wrote:
| already done, yup!
| janci5243 wrote:
| This might be completely a common knowledge, but I just learned
| recently that SPF (the number on most sunscreen products) is
| actually a multiplier of the time you can spend in the sun
| without any protection
|
| So having an SPF of 50 increases a time 50 fold, which really
| puts things into perspective. Never leave the house around
| lunchtime without sunscreen.
| jandrese wrote:
| Also remember however that the SPF numbers on most sunscreen
| are aspirational. They usually require you to apply a much
| heavier coat than most people think is reasonable and have
| shorter than you would expect full effectiveness window.
|
| As the article discusses it also depends on your skin. If you
| are a fair ginger then yeah, sunscreen is your life. If you are
| more swarthy then you can get away with some midday sun.
| outworlder wrote:
| > then you can get away with some midday sun
|
| No you can't. Or rather, you shouldn't. If you have more
| melanin you obviously have more protection. But your skin
| will still get damaged by a midday sun, and it will age
| faster than normal.
|
| This misconception that darker skin does not need protection
| is really harmful. Maybe that allows you to skip sunscreen
| for short periods of time, or in early morning, late evening.
| Not midday, unless "some sun" means just a few minutes.
| jandrese wrote:
| My understanding is that overuse of sunscreen is also
| considered harmful as it inhibits Vitamin D production.
| It's one of those areas where striking the right balance is
| difficult as it is different for everybody. As a result you
| had conflicting advice from every corner.
| ihumanable wrote:
| This is not correct, https://www.fda.gov/about-fda/center-drug-
| evaluation-and-res...
|
| <quote>
|
| There is a popular misconception that SPF relates to time of
| solar exposure. For example, many consumers believe that, if
| they normally get sunburn in one hour, then an SPF 15 sunscreen
| allows them to stay in the sun 15 hours (i.e., 15 times longer)
| without getting sunburn. This is not true because SPF is not
| directly related to time of solar exposure but to amount of
| solar exposure. Although solar energy amount is related to
| solar exposure time, there are other factors that impact the
| amount of solar energy. For example, the intensity of the solar
| energy impacts the amount. The following exposures may result
| in the same amount of solar energy:
|
| - one hour at 9:00 a.m.
|
| - 15 minutes at 1:00 p.m.
|
| </quote>
| csours wrote:
| It's correct, but with extra steps required for comparison.
| tgb wrote:
| I don't see anything in that article that actually
| contradicts the definition of SPF. It's basically saying:
|
| > It's a common misconception that speed determines how fast
| you get to your destination, but actually distance also
| matters. So speed does not reflect time to destination.
| Instead, speed lets consumers compare the level of relative
| quickness and that 60mph is quicker than 6mph.
|
| Obviously we need to hold other factors constant. It's not a
| useful point in when talking about speed and I don't see the
| point in talking about SPF. And it certainly doesn't mean
| that time to destination is inversely proportional to speed.
| ihumanable wrote:
| Quick someone hold the Sun's position in the sky constant
| for me so my incorrect understanding of SPF holds true :)
|
| I merely want to provide a fuller explanation of what SPF
| is from an authoritative source, in this case the FDA.
| thehappypm wrote:
| If you're standing under a UV light that's constant, I
| think the SPF === time works. In the real world, where the
| sun, ya know, rises and sets, this is actually a harmful
| assumption.
| taeric wrote:
| Neat. Curious how to interpret this when you are tanned some. My
| understanding is that doesn't change your skin type, but you do
| build some resistance. That not the case?
| janci5243 wrote:
| This article seems to say that getting a base tan helps to get
| 3-4 SPF, so your time-to-sunburn increases up to 4 times.
| https://www.health.harvard.edu/blog/problem-tanning-myth-bas...
|
| I would not rely on it overall tough.
| qmmmur wrote:
| You have a base level of resistance determined by your genes.
| When you get burned you tan and that burn is a function of time
| spent out in sun multipliednby that base protection. Tanning is
| our bodies response to the damage done by this as a form of
| preventing more damage. The damage however is accumulative.
| taeric wrote:
| This makes since sense, but still feels too simplified. I
| used to spend many hours outside and basically developed a
| skin type that was easily two types higher than I have
| normally. When this happened, I found I could definitely do
| longer without a hat or other sun shades with no negative
| impact.
|
| Fast forward a few years and I'm back to where the first few
| days mowing the yard will see me get burned. Give it a few
| weeks and I can go longer without a hat.
| qmmmur wrote:
| You repeatedly damaged your skin to maintain the tan.
| taeric wrote:
| I get that. But some damage is different from other
| damage. Getting callouses is similar to getting blisters.
| But one is much worse for you. (With the other being
| somewhat beneficial...)
|
| So my question is how bad is it, really? Straw man
| arguments of folks being ridiculously tanned from tanning
| beds aside, is there much trustable discussion over mild
| tans?
|
| Edit: Probably better asked in terms of my blister
| analogy. Is there benefit to getting tanned similar to
| building up callouses? Or is it purely cosmetic?
| qmmmur wrote:
| Getting burned once in a two year time span triples your
| risk of developing melanoma compared to not getting
| burned at all. That base level obviously depends on your
| genetics.
| taeric wrote:
| That is getting burned. Is tanning:burning the same as
| callouses:blisters?
|
| I suppose I am assuming callouses aren't really bad for
| you? Is that not true?
| qmmmur wrote:
| You don't have to be visibly horribly red to be burned.
| Even just a slight redenning of the skin or it being hot
| after being in the sun for a while can constitute a burn.
| version_five wrote:
| That was the first thing I wondered too. My skin is Type I or
| lighter going by the chart. But my neck and arms and face are
| much darker from a life spend outside. It says I can only go
| outside for seven minutes without sunscreen, which i believe if
| i was at the beach, but I know I can go outside much longer
| than that in a t-shirt without any burn.
| qmmmur wrote:
| You are repeatedly damaging your skin which is why it's
| darker.
| ReptileMan wrote:
| You are repeatedly damaging your muscles and tendons in the
| gym which is why they become bigger, stronger and denser.
| So where does that leave us?
| seattle_spring wrote:
| How many times have you heard of someone getting muscle
| cancer from going to the gym?
| qmmmur wrote:
| Are you dumb or just a troll?
| tgb wrote:
| This model doesn't take into account time of day, but many do.
| But those mostly seem to do so incorrectly, as far as I can tell.
| They tend to use the measure of "UVA/B incident on a horizontal
| square meter". However humans are not flat horizontal surfaces -
| and in fact a lot of my exposed skin is more vertical than
| horizontal. Therefore I think the correct measure should be
| "UVA/B incident on a meter-diameter sphere" or similar (where
| absorption from the atmosphere is the only contributor, not
| merely foreshortening). I was unable to identify numbers for this
| at all when I looked into it - does anyone know of a model that
| does this properly? Or just number of how much UVA/B is impacted
| by this?
| epiteton wrote:
| Try duplicating the project, it should give you access to the
| code. Also the API returns the current weather/UV index, so the
| result is always for the current time at the location.
| kingabzpro wrote:
| This is amazing interective dashboard like notebook.love it
| jeremyw wrote:
| Consider removing omega-6 seed oils from your diet. Like many
| others who have tried it, I now have a normal tan response, where
| in the past I burned in a heartbeat.
|
| Note: you do need to wait a few months for the fatty acid
| composition of your skin to turn over.
| VoiceOfWisdom wrote:
| My family(except for one brother) and I have completely cut all
| seed oils out for the last year. No longer burn at all, except
| for the brother that has not. He goes inside looking like a
| lobster.
| mijoharas wrote:
| Could you go into a little more detail on this and/or provide
| references?
|
| This is the first time I'm hearing about a link between omega-6
| oils and sunburn.
| simonsarris wrote:
| Same: I suspect a good omega 3 ratio greatly reduces skin
| damage with sun. Anecdotally it's worked for me and my wife
| when we started eating a lot more eggs/red meat and less O-6
| products. We haven't used sunscreen in a few years now because
| of it.
|
| There are some studies that suggest this is true, such as:
| https://pubmed.ncbi.nlm.nih.gov/7561154/ (note: N = 13)
|
| And Oregon State "Essential Fatty Acids and Skin Health"
| primer, which goes over what's going on in healthy skin.
| https://lpi.oregonstate.edu/mic/health-disease/skin-health/e...
|
| Their conclusion:
|
| > Supplementation with n-3 fatty acids in particular exerts
| protection from photodamage and photoaging.
| hawski wrote:
| But aren't eggs themselves overall much more an O-6 source
| than O-3?
| lettergram wrote:
| I almost exclusively refuse to wear sunscreen. The data isn't
| exceptionally clear if wearing vs no wearing leads to overall
| more or less cancer system wide. Further, it definitely reduces
| vitamin D production and has harmful chemicals when in the water
| supply and absorbed into your skin.
|
| You can wear very lose light cotton clothing, hats and avoid too
| much direct sun. Further, going out regularly will typically keep
| a tan (for most).
|
| The Amish have notoriously low rates of cancer and don't use sun
| block AND work outside all day. I typically try to imitate their
| methods.
| [deleted]
| overcast wrote:
| The Amish are also notoriously covered head to toe in clothing.
| Obviously if no sun touches you, it's difficult to be affected
| by it.
| Equiet wrote:
| There's a video which shows how you look like to a UV camera when
| you put sunscreen on. Also glasses with UV filters:
| https://www.youtube.com/watch?v=o9BqrSAHbTc
| [deleted]
| fouronnes3 wrote:
| My ultimate dream is a pair of magical glasses with a small
| knob on it, which when turned adjusts the wavelength you can
| see from deep radio all the way to high energy gamma. Just
| imagine seeing the entire spectrum.
| throwawaycities wrote:
| Not sure the other spectrums of light are intense enough on
| average for such glasses to work without them also emitting
| all spectrum of light (essentially a walking
| radar/lidar/X-ray/etc... machine).
|
| For example we of course have these types of "glasses" for
| infrared which is fine for humans because we give off
| significant quantities of infrared radiation, but lesser
| known is we also emit light in the visible spectrum, it's
| just not enough intensity for our rods/cones or inversely our
| rods/cones are not sensitive enough to observe the visible
| light we emit. Anyway your invention would be cool, even if
| it just ratcheted up the existing visible light spectrum
| enough we could see ourselves glowing in the dark...it would
| give people a new appreciation for Carl Sagan's quote that we
| are made of stardust.
| jandrese wrote:
| You want Geordi's VISOR from Star Trek.
| libraryatnight wrote:
| The episode where they hook up his visor so they can
| display what he sees on screen was always cool to me.
| fouronnes3 wrote:
| Yes!!
| cwkoss wrote:
| I know I do!
| irthomasthomas wrote:
| Thanks.... but now I need to buy a UV pass filter for my
| hyperspectral camera.
| version_five wrote:
| The video was cool but I'd also be skeptical of how they imply
| that freckles (including UV spectrum freckles) are "damage" to
| the skin or undesirable. It's neat that people look different
| under UV, and it's a cool adaptation that our skin pigments
| seem to target UV differently that visible spectrum... that's
| all I would confidently take away from the video
| throwawaycities wrote:
| I live in south Florida (tropical weather climate) and my
| shoulders are covered in freckles from sunburns growing up.
| Basically following the sunburn the skin would begin to peel,
| which started off as little circles (which I always assumed
| became the freckles).
|
| I don't know much about the process but always classified it
| myself as damage/scars. Though I could see calling non-
| sunburn induced freckles scars or damaged skin (or
| undesirable) as being inaccurate and just insensitive to
| people born with freckles.
| outworlder wrote:
| But in many (most?) cases, they are damage. I have visible
| 'freckles' in my shoulders. I wasn't born with them. There's
| further damage in some areas that had heavy exposure to
| sunlight. Same on the more exposed areas in my arms. Zero
| "freckles" or spots of any kind outside these zones. There's
| plenty of literature on this.
|
| Sure, they are an adaptation. One that's best avoided _while
| you can_
|
| Every time you get a "sunburn" and your skin turns red?
| That's DNA damage. The body is good at repairing that, but
| not perfect. Best not to take damage in the first place. And
| if you do, to at least reduce the total radiation amount.
|
| We shouldn't be singling out people based on their appearance
| of course. But there should be more awareness that skin
| damage is cumulative, and skin should be protected as much as
| possible.
|
| I regret not having done so when I was younger. As much as I
| hate sunscreen.
| cpncrunch wrote:
| >Sure, they are an adaptation. One that's best avoided
| _while you can_
|
| Why do you want to avoid this damage?
|
| Sun exposure and solar elastosis (sun damage to the skin)
| is associated with reduced mortality from melanoma:
|
| https://academic.oup.com/jnci/article/97/3/195/2544082?logi
| n...
|
| and a literature review which backs this up:
|
| https://adc.bmj.com/content/91/2/131.short
|
| And sun exposure reduces all-cause mortality:
|
| https://onlinelibrary.wiley.com/doi/full/10.1111/joim.12251
| TaupeRanger wrote:
| This comment is full of assumptions about an extremely
| complex and poorly understood relationship between two
| things that are _themselves_ very complex. The fact is, we
| evolved to live in the sun, just as most other land animals
| did. While it can damage us (just as anything in nature) it
| 's unclear to what extent this damage might be offset by
| the benefits of sun exposure, or to what extent sun
| exposure might have a hardening effect against further
| damage, extending the benefits even further. Sunscreen
| didn't exist for most of human history, and yet there were
| no plagues of skin cancer. The fact is, we simply _cannot_
| say with any certainty that "the skin should be protected
| as much as possible".
| tantalor wrote:
| Bug: you can safely sunbath -> you can safely sunbathe
|
| sunbath is a noun, sunbathe is a verb
| JadeNB wrote:
| A minor suggestion: the image for the Fitzpatrick skin type
| labels them "Type 1", "Type 2", etc., but the selector labels
| them "Type I", "Type II", etc.
| nerbert wrote:
| Neat! Wolfram alpha also does it.
| avidiax wrote:
| I'd argue that Wolfram Alpha does it better:
|
| https://www.wolframalpha.com/input/?i=uv+index+90210
| BugsJustFindMe wrote:
| Getting GeocoderQuotaExceeded
| jstastny wrote:
| Seems to be fixed now -- it has switched to different geocoding
| API.
| rho4 wrote:
| same
| cryptoz wrote:
| Worth mentioning that UVA and UVB are different, and that there
| are multiple sunscreen scandals happening right now where UVA
| protection is insufficient. UVB causes burns and tanning but UVA
| causes more cancer; and American suncreens especially - but also
| globally - are not telling the truth about how much protection
| they offer.
|
| You've got to be careful to really apply multiple layers of
| sunscreen with UVA protection in order to get the skin-cancer-
| reducing benefits. A thin layer does not do it. Thick layers
| required, and be warned, you sunscreen label may be lying to you
| about how much protection it offers.
| rplst8 wrote:
| You need to look for sunscreens that say "broad spectrum". That
| is the approved language in the U.S. for UVA protection.
|
| https://time.com/3924609/sunscreen-spf-uva-uvb/
| cryptoz wrote:
| Sorry to say, but that article is 6 years old. A lot has
| changed since then. Yes, you need broad spectrum, but the
| point of my post is that those labels are not always telling
| the truth. You do not always get broad spectrum sunscreen
| from a bottle that says it is broad spectrum sunscreen.
| plorkyeran wrote:
| "Broad spectrum" just tells you that it provides some amount
| of UVA protection. It doesn't tell you how much, and it's
| often much less than the UVB protection.
| Johanx64 wrote:
| Hard part is finding sunscreen which isn't cancerous or
| poisonous itself. 1 in 4 seem to have benzene in it. The
| sunscreen sitting on my shelf has talc in it. Etc
|
| If only I could just buy sunscreen without having to worry
| about any of this shit.
| clint wrote:
| If you look over that table, its generally the cheap
| drugstore sunscreens pushed by 2-3 large multinational
| companies.
|
| Buy a higher quality sunscreen (there are multiple reddits
| for this exact purpose) and you will not get poisoned by
| benzene and it won't be greasy and smelly.
| pdr94 wrote:
| This happened in South Korea, there were 3 brands that needed
| to pull their products because of this.
| https://www.nssgclub.com/en/pills/25875/solari-coreani-contr...
| okareaman wrote:
| It's even easier at altitude, such as at nice swimming lakes in
| the mountains.
| annoyingnoob wrote:
| Looks neat, failing on city lookup for me.
| niek_pas wrote:
| Same, looks like quota exceeded.
| ptsd_dalmatian wrote:
| This explains why going for a summer vacation directly from
| programmers winter dungeon produces painful moments quite
| quickly.
| ReptileMan wrote:
| Bars around the beaches usually have good shade and cold beer.
| pmoriarty wrote:
| For those who, like me, started to wonder how using sunscreen
| affects vitamin D production, here's the conclusion of _" The
| effect of sunscreen on vitamin D: a review"_:
|
| _" There is little evidence that sunscreen decreases 25(OH)D
| concentration when used in real-life settings, suggesting that
| concerns about vitamin D should not negate skin cancer prevention
| advice. However, there have been no trials of the high-SPF
| sunscreens that are now widely recommended. What's already known
| about this topic? Previous experimental studies suggest that
| sunscreen can block vitamin D production in the skin but use
| artificially generated ultraviolet radiation with a spectral
| output unlike that seen in terrestrial sunlight. Nonsystematic
| reviews of observational studies suggest that use in real life
| does not cause vitamin D deficiency. What does this study add?
| This study systematically reviewed all experimental studies,
| field trials and observational studies for the first time. While
| the experimental studies support the theoretical risk that
| sunscreen use may affect vitamin D, the weight of evidence from
| field trials and observational studies suggests that the risk is
| low. We highlight the lack of adequate evidence regarding use of
| the very high sun protection factor sunscreens that are now
| recommended and widely used."_
|
| https://pubmed.ncbi.nlm.nih.gov/30945275/
| 49531 wrote:
| Fortunately Vitamin D supplements are a safe and effective way
| to get the recommended amount. UV exposure is the most
| preventable cause of skin cancer[1] and not worth the risk.
|
| EDIT Forgot my link: 1.
| https://www.hhs.gov/sites/default/files/call-to-action-preve...
| nradov wrote:
| Your risk analysis is not scientifically valid. There is no
| reliable evidence that moderate sunlight exposure increases
| all-cause mortality.
| gojomo wrote:
| But, after 50+ years of rising sunscreen use, there's
| essentially no data showing more sunscreen use reduces skin
| cancer.
|
| Sunscreen definitely prevents sunburns, and almost certainly
| delays visible skin aging/weathering. Those may be enough
| benefits for some people.
|
| But the people/populations using more sunscreen are also
| having _more_ skin cancer. Some theories compatible with
| these observations are:
|
| * While preventing sunburn pain, sunscreen doesn't prevent
| the actual cancer-causing skin damage - and thus by allowing
| more time to be spent in the sun, actually worsened skin
| cancer rates. (This may have especially been a problem for
| the 1960s-1990s, when it was thought that only sunburn-
| causing UVB contributed to skin cancer - so sunscreens only
| blocked UBV. That encouraged _increased_ exposure to the
| mostly-unblocked UVA, now understood as an equal contributor
| to skin cancer. More recent sunscreens block UVA as well.)
|
| * Known carcinogens commonly used in sunscreens, or present
| as contaminants, are actually _causing_ increased rates of
| skin cancer.
|
| Anyone whose true worry is skin cancer should use shade &
| limited times of exposure - _not_ sunscreens. (Ensuring a
| spaced-repetition of gradually-increasing exposure, to
| develop a natural tan without ever reaching a peeling burn,
| is also likely naturally protective against skin cancer.)
|
| Further, while endogenous Vitamin D production relies on sun
| exposure, and low Vitamin D is correlated with health
| problems, oral Vitamin D supplementation may not replace all
| the benefits of sun exposure.
|
| Generally, large population studies show positive effects of
| moderate sun exposure on many health outcomes, including
| overall longevity, heart disease, and non-skin cancers.
| Meanwhile, Vitamin D supplementation studies have usually
| _not_ found that such supplementation alone reverses the
| correlations of many diseases with low Vitamin D. Thus,
| Vitamin D may not be the only mechanism by which sun 's
| benefits are achieved.
|
| So rigorous sun-exposure-minimization, even if it does reduce
| (often benign or increasingly survivable) skin cancers, may
| increase overall mortality through higher heart disease &
| other cancers. (Your HHS report mentions 9,000 skin melanoma
| deaths per year. There are 650,000 heart-disease deaths and
| 600,000 other cancer deaths.)
|
| Get sun. Use shade, clothing, & timing to ensure it's not so
| much sun that you peel. Use sunscreen sparingly, only when
| you can't moderate sun exposure other ways.
| psychometry wrote:
| >But the people/populations using more sunscreen are also
| having more skin cancer
|
| Um, you missed the most obvious explanation (assuming
| that's even true): People who have an elevated risk of skin
| cancer (due to geographic location and/or skin type) are
| likely to use more sunscreen for that very reason, but
| despite their sunscreen use they're still at an elevated
| risk of cancer because sunscreen cannot eliminate all risk.
|
| It's really no different than saying that people who are
| receiving more IV chemotherapy are also dying of cancer
| more often than people who aren't.
| gojomo wrote:
| This sort of confounder is common, but we have in the US
| a population that, over the decades, is (pre-exposure) no
| more pale/susceptible-to-burns.
|
| The public has been bombarded for decades with the health
| message to avoid the sun, and a deep tan has become less
| fashionable. (My younger friends, especially, treat
| minimizing tans/exposure as an almost religious
| obligation.)
|
| Sunscreens have broadened the wavelengths they block -
| they used to mostly skip UVA, thinking it harmless - and
| upped their SPF factors. (In the 1980s, I recall SPF15 as
| the max - now it's SPF30, SPF80, SPF100.) Sales & usage
| of sunscreen keep growing.
|
| But melanoma case rates are still on a long-term rising
| trend. Deaths have finally improved slightly in the last
| few years - likely from earlier detection & better
| treatment.
|
| If the population's generally the same, but slathering on
| far more sunscreen every decade - but cases still go up &
| mortality barely budges - there's little hint of
| effective protection.
| nomel wrote:
| The majority of my family has had skin cancer (we don't
| tan, we burn). It's usually in places you _can 't_ put
| sunscreen, like eyelids, close to the lips, etc.
| wahern wrote:
| > But, after 50+ years of rising sunscreen use, there's
| essentially no data showing more sunscreen use reduces skin
| cancer.
|
| 50% reduction in melanoma:
| https://pubmed.ncbi.nlm.nih.gov/21135266/
|
| 40% reduction in squamous cell carcinoma:
| https://pubmed.ncbi.nlm.nih.gov/10475183/
|
| See, generally, https://www.skincancer.org/skin-cancer-
| information/skin-canc...
|
| Perhaps you were thinking of basal cell carcinoma, the most
| common type of skin cancer. There does seem to be a lack of
| experimental evidence wrt BCC:
| https://www.hindawi.com/journals/jsc/2012/480985/ The
| skincancer.org FAQ conspicuously skips around that hole.
| gojomo wrote:
| Melanomas are the skin cancer of primary concern.
|
| Your "50% reduction in melanoma" link is interesting, but
| pretty small & low-powered - and followup comments (such
| as https://ascopubs.org/doi/10.1200/JCO.2011.35.5727)
| highlight potential major problems in study design. For
| example:
|
| * Study wasn't originally designed to detect effect on
| melanomas - that endpoint was added later. (This, alone,
| suggests possible p-hacking.)
|
| * Instructions thus didn't even direct sunscreen
| application to the areas melanomas most often occur. Yet,
| at followup both control & intervention groups had a
| disproportionate number of melanomas in _exactly_ the
| areas where application had been directed (and most
| applied, by self-reports, in both groups). As the
| commenters note, this is actually consistent with the
| theory that sunscreen encourages overexposure moreso than
| it protects.
|
| * Small changes in arbitrary study choices - like to what
| extent back/leg melanomas were considered (when those
| areas weren't part of the encouraged sunscreen-
| application area), or whether a 1, 2, or 4 year exclusion
| of early events applied - remove the claim of
| 'significance', suggesting a very fragile result.
|
| If the protective relationship of sunscreen were real,
| it'd have lots of studies with robust results. Or, the
| massive increases in recent decades in SPF factors,
| sunscreen purchasing/use, and sun-avoidance messaging and
| practice would've reduced melanoma rates. Instead,
| melanoma rates keep going up. To me, that's far more
| powerful evidence than a repurposed study with 11 more
| melanomas (but fewer invasive ones!) in a slightly-less-
| sunscreen-using control group.
|
| The squamous study is also murky, though not as much. Its
| abstract notes, "There were no significant differences in
| the incidence of first new skin cancers between groups
| randomly assigned daily sunscreen and no daily sunscreen
| (basal-cell carcinoma 2588 vs 2509 per 100,000; rate
| ratio 1.03 [95% CI 0.73-1.46]; squamous-cell carcinoma
| 876 vs 996 per 100,000; rate ratio 0.88 [0.50-1.56])."
| The same number of people got new skin cancers in both
| groups! It's only the secondary count of tumours where
| the control group had more. I'm unsure that's an
| important protective effect.
|
| But going back, I really should have said: "no data
| showing more sunscreen reduces _deadly_ skin cancers ".
| There's a reasonable amount of evidence sunscreen reduces
| various kinds of mild skin-tumours, much like the
| obvious-to-the-naked-eye effectiveness against sunburns.
|
| But for melanomas/death-by-skin-cancer - the top worry of
| most sunscreen users - any effect is either very weak,
| non-existent, or possibly even inverse.
| 49531 wrote:
| > * Known carcinogens commonly used in sunscreens, or
| present as contaminants, are actually causing increased
| rates of skin cancer.
|
| I am curious to see a citation for this claim.
|
| > Generally, large population studies show positive effects
| of moderate sun exposure on many health outcomes, including
| overall longevity, heart disease, and non-skin cancers.
| Meanwhile, Vitamin D supplementation studies have usually
| not found that such supplementation alone reverses the
| correlations of many diseases with low Vitamin D. Thus,
| Vitamin D may not be the only mechanism by which sun's
| benefits are achieved.
|
| I am also curious to see these studies, and wonder if they
| control for other variables like physical activity.
|
| I think it's an incorrect framework to say that you have to
| choose between skin cancer and heart disease, you can avoid
| both through different lifestyle choices.
| baumandm wrote:
| Here's a recent HN discussion of a study that found
| benzene in 27% of tested sunscreen samples:
| https://news.ycombinator.com/item?id=27292387
| gojomo wrote:
| Many intentional functional ingredients in sunscreens are
| known carcinogens and absorbed at levels beyond any
| safety testing:
|
| https://www.webmd.com/skin-problems-and-
| treatments/news/2020...
|
| Contamination of sunscreens with common dangerous
| byproducts of industrial processes like benzene is
| common:
|
| https://www.washingtonpost.com/lifestyle/wellness/benzene
| -su...
|
| By comparison, shade contains no carcinogens.
|
| Sun exposure correlated with longer life (even while
| _also_ being correlated with more cancer deaths!):
|
| https://www.health.harvard.edu/blog/heres-something-
| unexpect...
|
| An earlier broad survey also finding natural sun exposure
| decreasing all-cause mortality (but not use of tanning
| beds, despite similar effects on Vitamin D production,
| again suggesting D-supplements alone don't replicate the
| sun):
|
| https://cebp.aacrjournals.org/content/20/4/582
|
| I'd agree, it is hard to disentangle these correlations
| with things like general levels of outdoor _activity_ and
| socializing.
|
| But even so: if people who are healthy for other reasons
| tend to spend more time outside in sun, maybe it'd be a
| good idea to join them, & perhaps absorb their _other_
| habits as well, rather than live in fear of the sun?
| (Maybe even the sun is damaging on many levels, but the
| other benefits of activities inherently done more under
| the sun offset those effects, even if just via mood
| /optimism?)
|
| I'd say instead that it's an incorrect framework to
| embrace an illusion of total control "through different
| lifestyle choices" without tradeoffs. Every activity has
| a mix of risks and benefits. Certain vigorous activities
| with a higher risk of accidental death may deliver other
| fitness and social benefits. If an extra 5 hours of sun
| every week doubles melanoma death risk, but reduces
| cardio/cancer death risk just 1%, that sun would still be
| a net-mortality benefit.
|
| Such tradeoffs are real & everywhere. Trying to engineer
| both benefits - "can I do everything other healthy people
| do usually do outdoors indoors? can I find the least-
| dangerous sunscreen? will vitamin D supplments, perhaps
| with a bunch of other diet changes, simulate the sun's
| benefits?" - also includes costs, in research time,
| psychological focus, neurotic behaviors, etc, for
| diminishing returns.
| seattle_spring wrote:
| Can you provide some peer reviewed sources for your claims?
| Your whole comment reads like that thoroughly debunked
| "scientists blow the lid off of sunscreen" [1] article that
| was going around a few years back.
|
| [1] https://millerfamilydermatology.com/sunscreen-myth/
| gojomo wrote:
| Here's a good recent overview of reasons to doubt the
| efficacy of sunscreen against fatal skin cancers:
|
| https://www.outsideonline.com/2380751/sunscreen-sun-
| exposure...
|
| (Most recently discussed on HN at
| https://news.ycombinator.com/item?id=23086211)
|
| Similar doubts have existed for decades - here's a 1993
| variant reporting some of the trends that already didn't
| add up, back then:
| https://www.motherjones.com/politics/1993/05/melanoma-
| sunscr...
|
| Another branch reply provides more sources about
| sunscreen chemicals & sun-longevity correlations:
| https://news.ycombinator.com/item?id=27520144
| Spooky23 wrote:
| I don't know why your comment is being voted down, it's a
| reasonable one, although I disagree with parts of it.
|
| Depending on your skin type, "Get Sun" may not be good
| advice, especially if you make a mistake. A single
| significant sunburn in your teens significantly increases
| your lifetime risk of getting a skin cancer, of which
| melanoma is just one. My wife developed melanoma and is in
| remission. She is fair skinned and very sun-cautious --
| typically using clothing as a primary barrier with
| sunscreen. Like anything risk assessment and risk tolerance
| is key and difficult to assess.
|
| Another factor to consider is that mortality doesn't always
| tell the story. Some surgical procedures introduce
| significant scarring. Treatment for a stage-2 melanoma will
| often include removing lymph nodes, which introduce other
| complications. Also be careful, as past diagnoses of
| cancers were not great. That melanoma that moved into an
| organ may not have been classified correctly in 1960.
|
| Personally, my advice is go outside, dress appropriately
| and use a mineral-based sunscreen if you're going to be out
| for more than a half hour or so. Don't go swimming at solar
| noon. Don't tan. Wear a rash-guard at the beach. Wear a hat
| at the ballgame.
| loudtieblahblah wrote:
| Sunshine is more than just a source of VitD.
|
| UVA has also been shown to lower blood pressure. This is
| probably the result of UVA causing the release of nitric
| oxide from skin stores, which promotes widening of blood
| vessels. It also acts as an antioxidant to prevent damage to
| cells.
|
| People who don't get enough sunlight have altered cellular
| defense mechanisms that predispose them to excessive
| inflammation, which can result in autoimmune diseases.
|
| One could argue you can supplement to replace VitD, but are
| you supplementing your children? From what age? How
| regularly? What's the quality of the supplementation? How do
| the poor maintain access to supplementation?
|
| Then you run into the problem that long term, large(r) doses
| of Vitamin D causes kidney problems.
|
| A study ( https://pubmed.ncbi.nlm.nih.gov/21430082/) found an
| association between low vitamin D levels and the development
| of type 2 diabetes. For every ten-unit decrease in blood
| vitamin D levels, we found a 10% increased risk of developing
| this form of diabetes over the following five years. when
| they gave supplements of vitamin D to patients with low
| vitamin D levels who were already at risk of developing
| diabetes, there was no overall improvement in their
| sensitivity to insulin. Nor was there a change in their blood
| glucose levels compared with those given inactive tablets.
|
| I'm betting, not just in this case, but the act of your body
| making it's own VitaminD creates benefits we are not yet
| aware - that oral consumption of a pill isn't going to
| compensate for.
|
| nevermind MOST of VitaminD pills use soybean oil or some
| other horrible Omega-6 ridden, cheap seed oil as it's
| delivery method.
|
| Outside time in the sun is helpful in ways not tied to VitD,
| as well. circadian rhythms are regulated by bright light
| exposure. You can't get these lumens by waking up and sitting
| inside all day. The heat from the sun is capable of reducing
| physical stresses on the body's cells and by increasing heat
| production.
|
| Another important potential effect of sunlight is UV-induced
| suppression of the body's immune system. Solar radiation does
| this by altering the activity of the white cells involved in
| turning on the body's defence mechanisms. This may seem like
| a negative, but it's vital for people to reduce inflammation
| and when considering how the earth's population spreads out
| autoimmune disorders (higher percentages the more you get
| away from the equator), this may be a secondary factor on top
| of VitaminD.
|
| IMHO -
|
| people need to find a balance with sunscreen and sunshine. if
| you know you're going to risk a burn, put it on and reapply
| when necessary.
|
| if you're worried about cancer, eat some cruciferous
| vegetables regularly to make sure you get lots of
| sulforaphane which protects against skin cancer. Get regular
| derma checkups.
|
| but when looking at auto-immune issues (that once you have
| one, your supplementation isn't going to undo it), the
| depression issues, and so forth - isn't worth skipping out on
| sunshine.
|
| Skin cancer may be the most preventable but it's also a
| fairly unlikely cancer, as far as cancers go - and while it's
| one of the scarier cancers, catching it early with derma
| appointments is key to survival. Catching it early has a high
| survival rate.
|
| An auto-immune issue, on the other hand, will shorten your
| life and make you suffer along the way, increasingly, for the
| rest of your life. It's not just a death sentence. It's a
| slow-slog through hell on the way there. Most people never go
| into a permanent remission of Ankylosing spondylitis or MS.
| It just slowly destroys you, it handicaps you, and then it
| kills you. And along with all that suffering, is your kids,
| parents and partners suffering right along with you. Yay -
| therapy sessions for everyone.
|
| It's not just auto-immune issues. Depression, anxiety, even
| certain cancers themselves all have some relation to low
| vitamin d.
|
| IMHO - sunlight needs to have it's saturated-fat moment where
| we realize that a lot of the fear mongering simply wasn't
| warranted. And that the cures for some diseases end up being
| the catalyst for many others that are far more likely.
|
| How many people are afflicted with an autoimmune issue? how
| many with debilitating depression? Compare those numbers to
| skin cancer. Compare the deaths. Compare the suffering.
|
| Then try to find a balance.
| gojomo wrote:
| _" I'm betting, not just in this case, but the act of your
| body making it's own VitaminD creates benefits we are not
| yet aware - that oral consumption of a pill isn't going to
| compensate for."_
|
| We are already aware of a direct benefit: the skin's
| production of Vitamin D uses up bodily cholesterol.
| External supplementation doesn't do that.
|
| (I agree there are likely others we'll document later.)
| mywittyname wrote:
| Very good information.
| Toine wrote:
| That was really enjoyable to read, thanks for sharing.
| loudtieblahblah wrote:
| it should also be noted that consumption of certain
| antioxidants protect against skin cancer (most notably
| sulforaphane found in Cruciferous Vegetables).
|
| >Nonsystematic reviews of observational studies suggest that
| use in real life does not cause vitamin D deficiency.
|
| yeah, but that's an observational study.
|
| I'm not anti-sunscreen and if you burn or get dark/deep
| freckles easily, I'm even more "pro" sunscreen for you.
|
| But when looked at the number of diseases and problems
| correlated to Vitamin D deficiency and looking at the
| relatively low risk of contracting melanoma (as scary as that
| cancer can be if caught late), to me it's a balancing act.
|
| Consuming mass amounts of VitaminD over long periods of time,
| orally, can cause kidney problems.
|
| If you look at auto-immune issues globally, the percentage of
| the populations that have them sky rocket the further you get
| away from the equator. Depression, anxiety, even certain
| cancers themselves all have some relation to low vitamin d.
|
| Sunlight, the type that allows UV-B to penetrate your skin, is
| a human necessity.
|
| And like a lot of things we need (Vitamin C and E, or
| polyunsaturated fats, carbohydrates, etc), too much of it will
| cause you problems and/or kill you, not enough of it will cause
| you problems and/or kill you. And trying to anecdotally perform
| some balancing act without constantly running tests on
| yourself, is difficult.
|
| My rule of thumb is put on sunscreen if you are out long enough
| to risk a burn, re-apply when necessary. Otherwise, soak up the
| rays.
| pmoriarty wrote:
| _" Consuming mass amounts of VitaminD over long periods of
| time, orally, can cause kidney problems."_
|
| What counts as massive?
|
| And is consuming massive amounts of Vitamin D necessary to
| prevent deficiency?
| loudtieblahblah wrote:
| if you're like most of the western world, especially if you
| have an indoor job and indoor hobbies (we spend an awful
| lot of time binging tv shows, playing video games, working
| on computers, etc..), you're not outside all that much
| unless it's to hop in the car and go to another indoor
| place.
|
| and chances are you have a deficiency.
|
| Most vitamins tell you to take 2,000 IU. Upper limits are
| typically stated to be 4,000 IU. But there's been no
| established harmful upper limit either.
|
| This leads a lot of people into thinking more is better,
| this is doubly true if they have some kind of pre-existing
| condition that's linked to low VitaminD and they're
| desperate to heal themselves. They read quack stories on
| the internet about how 10,000 IU doses help cure MS and
| they do it too.
|
| It's also made worse by so-called "smart" and "qualified"
| people like Dr Rhonda Patrick essentially turning herself
| into some pop-health guru and when she tells people what
| she supplements with (5,000-6,000 IU), many people feel she
| knows what she's talking about and copies her. But the
| reality is, she takes A LOT of supplements and she has zero
| idea how they all mix with each other, especially at the
| supplementation levels in which she's consuming them.
|
| of vitamins that can be abused, VitaminD is mostly safe.
| But a lot of folks go a bit crazy with it and have hurt
| themselves.
|
| VitD supplements are also, often, in soybean oil, which is
| horrible for you. VitD needs to be consumed with a fat, so
| If you're going to supplement, you spend the extra money
| for it suspended in coconut oil instead.
| mywittyname wrote:
| I think you're API key might be out of requests. I'm getting this
| error, no matter what location I put in, even though the Location
| block correctly returns the coordinates for whatever city I put
| in. Exception
| Traceback (most recent call last) <ipython-
| input-5-9b29f394b1fd> in <module> 7
| location_response = requests.get(f'https://api.opencagedata.com/g
| eocode/v1/json?key={OPENCAGEDATA_API_KEY}&q={Location}&no_annotat
| ions=1&limit=1') 8 if not location_response.ok:
| ----> 9 raise Exception('Location not found') 10
| 11 location_json = location_response.json()
| Exception: Location not found
| mtmail wrote:
| OpenCage here. We set a higher number of requests for the user
| now, seems to work again.
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(page generated 2021-06-15 23:01 UTC)