https://mobile.twitter.com/FarLeftKyle/status/1495198848200974338

  • sooper_dooper_roofer [none/use name]
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    edit-2
    3 years ago

    white people get all the D they need from just 5 minutes of sunlight exposure. it takes much longer for a dark skinned person

    People of all colors should wear sunblock

    no lol

    a black/Asian person is 20x less likely to develop skin cancer. In the cases it does occur, it's questionable if it's caused by sun damage, because sun damage isn't the only thing that can cause cancer.

    the only scenario where a dark skinned person should wear sunblock is if they're staying outside for like 7 hours straight in blinding hot sun. And even then they're mostly good for the first 3 hours

      • sooper_dooper_roofer [none/use name]
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        edit-2
        3 years ago

        From your own source:

        Another contributor to this statistic could be instances of acral lentiginous melanoma (ALM), a type of melanoma commonly diagnosed in the black community. It forms in areas not exposed to the sun: the palms of the hands, the soles of feet, and even underneath nails. Though not related to sun exposure, the areas where the cancer tends to form, no doubt has a hand in the often-delayed prognosis.

        Hmm, let's look a bit deeper: https://dermnetnz.org/topics/acral-lentiginous-melanoma

        Acral lentiginous melanoma accounts for 29-72% of melanoma in dark-skinned individuals but less than 1% of melanoma in fair-skinned people

        In other words, half of the already-low skin cancer incidence in dark people is NOT EVEN RELATED TO SUNLIGHT.

        I've basically proven you wrong already but I'll address your points anyway:

        1. Cool, I'm South Indian. And okay. I prefer targeted indepth advice over wine-mom healthline articles though.

        https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5946242/
        https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5946282/

        Brown-skinned people require at least 25 minutes of sunlight, whites only 9, to acquire sufficient vitD. Since skin damage and vitD are both driven by UV, this is going to be 1-to-1 relation with "safe limit for sunlight". So whatever amount of sunlight it takes to burn white people, it's going to take brown people 3x more. ("Brown" in this context is the average North Indian skintone, as that's what the "UK South Asian" population mostly consists of. I, and also most Black people, are even darker than this.)

        As for the "safe limit of sunlight exposure", a bunch of assorted sources say 15-20 minutes, which means the Brown person estimate would be probably 45-60 minutes. Higher if you're very dark.

        1. see above, the crux is how long "prolonged" means.
        2. except it's the same globally too, not just in the USA.
        3. all races are socially constructed. "Asian" in the US refers to a group of mostly East Asian people, and most US Chinese are from Southern China. At this point you might as well ask why Italian-Americans are being grouped in as "white" along with Swedish-descended Minnesotans.
        4. Probably because there are too few mixed race people of an exact category to make a cohort out of. There's no South Indian category either.
        5. The statistics are obviously from the US.
        6. This has nothing to do with wearing sunscreen.
          • sooper_dooper_roofer [none/use name]
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            edit-2
            3 years ago

            and therefore protecting your skin from the sun is generally a good idea, regardless of your skin color

            except it's not, if you plan to spend under 1 hour outside, and you have medium brown or darker skin.

            if black people are less likely to get health care or recognize melanoma early on, then that means they should take measures to protect their skin by wearing sunblock something you started off this conversation by saying “no lol” to

            if you're going to take such measures, then you already know about the real (albeit tiny) risk of melanoma in Black people. The vast majority of these victims are people who THEMSELVES don't even suspect that they have skin cancer, let alone their doctors. So simply knowing about this issue is already going to give you a huge leg up in the case of melanoma, even if you DON'T wear sunblock.

            Also, anything about this has to be weighed against the MUCH larger issue of vitamin D deficiency, and various other problems associated with not getting enough radiation.

            you don’t have to dismiss my source as “wine mom”

            I mean it's literally equating sunblock with skin cancer when over half of all skin cancers in Black ppl are totally unrelated to UV radiation. It's extremely wine mom, almost all of these types of general public articles are.

            You’re likely to get cancer from those too, but people still do it if they feel like it

            Not comparable, smoking/drinking has never been shown to have a causative healthful effect independent from other variables. Sunlight has (for obvious reasons), so blocking it is inherently bad

            not all “black” people are dark skinned, especially in the united states.

            true, but all claims are leveled to the average of that population. The average Black person is dark.

            One can raise similar qualms about blue-eyed whites being extra-susceptible compared to brown eyed ones. etc

              • sooper_dooper_roofer [none/use name]
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                edit-2
                3 years ago

                you haven’t proven that protecting your skin isn’t a good idea, only that it might not be quite as necessary for darker skinned people.

                I have proven that if you have type 5 skin, you do not need to wear sunblock for exposures up to 1 hour.

                Actually, I didn't prove this, a bunch of scientists did. I just looked it up

                  • sooper_dooper_roofer [none/use name]
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                    edit-2
                    3 years ago

                    this is a far cry from your initial “no lol”

                    Not really, because I'm using the most conservative margins possible. I remember a source showing vitamin D concentration over time in sunbathing black/white subjects, and the blacks after 2 hours didn't even reach what the whites had at 20 minutes. I can't find that source right now, so I didn't cite this, but the "acceptable limit" for dark skinned type 5 people is probably a lot higher than 1 hour.

                    Personally, I've sunbathed for 3 hours without getting burned, and only a very slight tan.

                    Again, the study was using socially constructed self-reported races, lower sample sizes for nonwhite people

                    It was 52 people. Small sample sizes are less relevant when the effect size is large enough.

                    and at the end of the day still admitted that there is a nonzero chance of getting sun-related skin cancer if you’re not white. Wear sunblock.

                    Or don't wear sunblock. Because the effects of vitamin D deficiency and Seasonal depressive disorder are astronomically more likely than getting skin cancer for a dark-skinned person. Regards, an actual dark skinned person

                      • sooper_dooper_roofer [none/use name]
                        ·
                        3 years ago

                        “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”

                        From studies done on white people, yes.

                          • sooper_dooper_roofer [none/use name]
                            ·
                            edit-2
                            3 years ago

                            where in that study does it say they only looked at white people?

                            The authors save 1 are all Anglo names (one is literally named Whiteman lul), and the text doesn't mention race/ethnicity which means they are exclusively done on whites, or at best a 90:10 split of whites:blacks (which effectively means the results only matter for whites)

                            http://ds-wordpress.haverford.edu/psych2015/projects/chapter/weird-populationsunrepresentative-sampling/

                            My only point is that it doesn’t hurt to wear sunblock

                            yes dude, it literally does. and there's no reason to wear it for the 1st hour of sunbathing.

                            Don’t wear sunblock if you don’t want to. It’s your risk, not mine.

                            Dark skinned people in general should err on the side of NOT using sunblock.

                              • sooper_dooper_roofer [none/use name]
                                ·
                                3 years ago

                                really rigorous science you’re doing here. Are you really implying that you know the race of the participants in the study based on the author names?

                                Holy shit dude, yes. How do you not know this? It's a meta-analysis. That means they look at a bunch of different studies.
                                That means that, UNLESS OTHERWISE SPECIFIED, these are going to be mostly Western studies, which are done on populations that are overwhelmingly white.

                                If a Western study deals specifically with a non-white population, it almost always says so right in the title.

                                If you don't believe me just look at their references, and the names of the people/titles.

                                https://www.semanticscholar.org/paper/The-effect-of-sunscreen-on-vitamin-D%3A-a-review-Neale-Khan/9c77216902252c88dc801342a4a31493e9062078?sort=relevance&citedPapersSort=relevance&citedPapersLimit=10&citedPapersOffset=20

                                  • sooper_dooper_roofer [none/use name]
                                    ·
                                    edit-2
                                    3 years ago

                                    There are probably a few use cases, like if you're lifeguarding on the beach all day all summer long, even a dark-skinned person might benefit from it.

                                    It's not just vitamin D, it's also seasonal affective disorder and thousands of other interactions unknown to science, because science only holds up a candle in an unlit auditorium (and in the case of funding for POC-centric studies, it's more like a glowing ember). Dark-skinned people evolved taking in plenty of sunlight, that's why they're dark. There are certainly dozens of downstream, subtle effects of light-deprivation which science hasn't even begun to describe. but yea

                  • sooper_dooper_roofer [none/use name]
                    ·
                    3 years ago

                    as for the vitamin D thing, you can literally get that from supplements and food.

                    okay, that doesn't fix Seasonal Affective Disorder though. You need the actual full spectrum light for that.

                  • sooper_dooper_roofer [none/use name]
                    ·
                    3 years ago

                    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

                    that study reviewed other studies which were almost exclusively done on Europeans, so it's irrelevant.

                    It's possible and even probable that sunscreen has a UV-blocking effect that is enough to shut out the modicum of vitD-production that dark people have, and enough to give big returns in burn protection to pale skin, but not enough to block vitD production in pale skin.

                    How about instead of me playing defense here, someone proves to me that a dark-skinned person can even get UV-induced skin cancer, for starters? This whole conversation, myself included, has assumed this is even possible, with no evidence. 29-72% (let's call it an even 50%) of melanoma in dark-skinned individuals is Acral Lentigious Melanoma, which is not UV-related. What's the other 50%? For all we know it could also be mostly unrelated to UV exposure.