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Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior
- taylorius 4y agoInteresting. A possible mechanism for the legendary passion of people from "hot blooded" countries?
- thrown_22 4y agoAll that's racist is new and progressive again. I'm still waiting for someone to explain the difference between colored people and people of color.
- ETH_start 4y agoIf anything, people who originate in cold climate countries visiting hot-blooded countries would receive more UVB due to less skin melanin, and thus be more hot blooded than the natives of hot blooded countries when interacting with them, and vice versa, so that would't explain the association.
- tcldr 4y agoAh, the ‘Brits Abroad’ phenomenon finally explained.
- Jugurtha 4y agoSomething that fascinated me with Russians is how they go out of their way to get every bit of sunlight. I mean, they act like sunflowers, even standing to face the sun and open their arms on the beach, and orienting themselves towards it. They'll go to the beach at ungodly hot hours and stay under the sun, in Tunisia, during summer! It is amazing because I'm really dark and dark skinned, I'm also native of the region (Algeria), and even then, I'll protect myself and stay in the shade because I'll get sunburnt very easily if I don't take precautions. They're fair skinned and they're not as cautious. It's just incredible.
- shipman05 4y agoAnecdotal, but not all fair skinned people react the same to sun. My wife and her Polish-descended family get a nice golden tan from sun exposure. My English-descended family and I just burn instead. But we all look equally pale during the winters. Russians are ethnically much closer to the Poles
- derefr 4y agoImplying that a primary causal factor for globally-declining birth rates could be... increased adoption of sunscreen, leading to decreases in libido? (I'm only half-joking; the countries that are most obsessed with keeping skin white — and so are likely the highest sunscreen users — are also the countries with the lowest birth rates.)
- dragonwriter 4y ago> (I'm only half-joking; the countries that are most obsessed with keeping skin white — and so are likely the highest sunscreen users — are also the countries with the lowest birth rates.) Obsession with keeping skin white is not something I normally see associated with South Korea, Singapore, or Bosnia and Herzegovina.
- tellmelies 4y agoHave you ever tried to buy sunscreen in Asia?
- shard 4y agoObsession with keeping skin white has been a major trend in Korea for a long time, have you seen all the weird hats and face masks that ajummas wear in order to reduce sun exposure?
- Apfel 4y agoCan't speak much for Bosnia but in most of South East Asia it's nigh on impossible to find any body wash, sunscreen or moisturiser without whitening products added.
- bushbaba 4y agoIf that’s the case then it’d come as a relief. But I doubt it. Realistically the fact wage to housing/health/education/childcare is a bigger contributor.
- yjftsjthsd-h 4y ago> the countries that are most obsessed with keeping skin white — and so are likely the highest sunscreen users Isn't it rather more about avoiding skin cancer?
- mercy_dude 4y agoQuestion: how does sunscreen affect these outcome ? I have been in a UV-high indexed area for over 2hrs a day under sun and wondered if applying sunscreen everyday as I have to exposed parts such as arms and legs have negative consequences since all of them have benzene. Now this seems to be another reason for not doing so?
- arbol 4y agoNot directly answering your question but related: "early sunscreen formulations were disastrous, shielding users from the UVB rays that cause sunburn but not the UVA rays that cause skin cancer. Even today, SPF ratings refer only to UVB rays, so many users may be absorbing far more UVA radiation than they realize." https://www.outsideonline.com/health/wellness/sunscreen-sun-exposure-skin-cancer-science/ https://www.outsideonline.com/health/wellness/sunscreen-sun-...
- samename 4y agoHow can you know if it does both? Look for UVA on the bottle?
- mattlondon 4y agoThe UK - and I presume Europe - has a star rating for UVA protection in addition to SPF. Some details here: https://www.nhs.uk/live-well/seasonal-health/sunscreen-and-sun-safety/ https://www.nhs.uk/live-well/seasonal-health/sunscreen-and-s... Tl;Dr - you want minimum 5-star 30 SPF for your daily cream.
- collegeburner 4y agoDo people actually use sunscreen every day? I wouldn't think a little sun (well before a burn) is that likely to cause problems?
- FullStackAda 4y ago
- gregsadetsky 4y agoOne of the referenced papers [0] concerning addiction to UV light (in rodents) is fascinating as well..! “UV light is an established carcinogen, yet evidence suggests that UV-seeking behavior has addictive features” “Opioid blockade also elicits withdrawal signs after chronic UV exposure” [0] https://pubmed.ncbi.nlm.nih.gov/24949966/ https://pubmed.ncbi.nlm.nih.gov/24949966/
- lapsis_beeftech 4y agoWhat might be going on here is that the UV induces radiation damage, which leads to endorphin release as part of the body's response to injury and pain. I have experienced this effect myself at times after getting a sunburn; the endorphins blocked the pain entirely and it was moderately euphoric. I know how dangerous sunburns are but if I was a rodent I would likely seek ways to repeat the experience.
- qvrjuec 4y agoThe melanotan peptide's effect on melatonin production and libido is super interesting considering this finding
- sitkack 4y agoCould be a signaling behavior to encourage spring births. Does UVB peak in the middle of the summer? 9 months later is probably the best time to birth a child for that child's success.
- ilaksh 4y agoThat seems possible but also more directly winter may be a bad time to start a pregnancy.
- techdragon 4y agoAvoiding the birth of a child right before winter would be advantageous for its survival… winter being (on average, not all regions/locales obviously) the hardest month to survive evolutionarily speaking this would be a beneficial trait and be likely to stick around. Ideally you want your early hominid babies at the end of winter through spring and summer so at worst they are though the first few fragile months that put the most drain on the mother, before the harshest winter weather sets in. While not globally consistent due to regional weather differences it makes sense for there to be a broad average seasonal benefit.
- littlestymaar 4y agoExcept those “early hominid” lived in Africa, which isn't known to be the place with the harshest winter. And the fact that humans living in temperate climates and humans in tropical areas belong to a single species makes me believe that adaptation to winter wasn't that big of an evolutionary factor.
- yxhuvud 4y agoNow you assume this wouldn't be something that is common for most mammals. In places where there is always sun there is no reason to evolve away people having more sex when there is sunny. Meanwhile here in northern Europe we get markedly more children during March-April. Which of course could be a sociological thing, or depend on something else, but still.
- samstave 4y ago
- totony 4y ago"The questionnaire we used measured romantic passion, rather than physiological/sexual passion, due to institutional review board (IRB) ethical concerns regarding sensitive sexually oriented questions." Curious about this. I understand ethical boards for psychological blind studies and such, but for questionaires?
- xyzzyz 4y agoYes, it’s stupid. IRBs today are, on net, more of a detriment to science than a benefit. When they block a stupid voluntary questionnaire for being “unethical”, just imagine how much other useful science is not being done, because of concern lack of ethics of a similar grade.
- freemint 4y agoIRBs look like a net detrement to most studies because they are a mechanism to prevent really bad/unethical experiments in the far tails of distribution. If those extreme studies were to happen at a non suppressed rate we would be asking for IRBs and talking how science can't regulate itself. So IRBs might be effective but they suffer from the prevention paradox.
- thrown_22 4y agoIRBs are a net negative because really bad/unethical experiments are done with no oversight by private entities. Their only purpose is to keep ethicists employed.
- klodolph 4y agoThis has got to be one of the worst takes on IRBs I’ve ever heard. The basic argument here is that rules are ineffective because bad actors ignore them. - Before IRBs, unethical experiments were done by professors and grad students with disposal to all of the resources they normally have. - People don’t always know what the ethical implications of their study is, or how it could negatively impact participants. - The IRBs are not there to stop research. They are there to help people figure out how to conduct research ethically.
- amelius 4y agoBremelanotide, a medication used to treat low sexual desire in women, has skin hyperpigmentation as a side effect. Could there be a connection? https://en.wikipedia.org/wiki/Bremelanotide https://en.wikipedia.org/wiki/Bremelanotide
- adaml_623 4y agoInteresting article. This sentence was interesting: Very early in the process one of the scientists, Mac Hadley,[15] who was conducting experiments on himself with the peptide melanotan II, injected himself with twice the dose he intended and experienced an eight-hour erection, along with nausea and vomiting.[13]
- macinjosh 4y agoI don't understand. Sounds like a typical Saturday night to me.
- somedude895 4y agoMy bodybuilder friend used to inject Melanotan II (?) and would get super tan after just a couple days of summer. He'd also get wild random erections while on it. It's an anecdote, but the post title instantly made me think of that.
- Scoundreller 4y agoThere’s a few decades of small studies confirming this: from 2000: https://pubmed.ncbi.nlm.nih.gov/11035391/ https://pubmed.ncbi.nlm.nih.gov/11035391/
- gizajob 4y agoI could tell Aussie girls were different.
- water8 4y agoOr maybe tan people just look more attractive and get more attention
- felipelalli 4y agoOr just people that work in field don't watch so much porno.
- amelius 4y agoWould it make sense for a curious hacker to try out a narrowband UV-B lamp? https://www.proflamps.com/datasheets/Philips%20Phototherapy-brochure-Global-final.pdf https://www.proflamps.com/datasheets/Philips%20Phototherapy-...
- funstuff007 4y ago
- sooheon 4y agoThere is a corner of the biohacking sphere for everything, including this: https://getchroma.co/product/chroma-d-light/ https://getchroma.co/product/chroma-d-light/ https://www.sperti.com https://www.sperti.com I never bothered with a device because we have the actual sun for free, and the potential for misuse is enormous -- it's trivial to accidentally blind yourself.
- amelius 4y agoThanks. I was thinking of mounting a light onder my table, so the skin in the legs can pick up the UV-B, thereby reducing safety risks and also distraction. It would be interesting to see if a day of programming could give me the same benefits in terms of well-being as a day surfing waves :)
- jonahbenton 4y ago(2021)
- pawsforthought 4y agoAlso, in mice [1]. [1]: https://mobile.twitter.com/justsaysinmice https://mobile.twitter.com/justsaysinmice
- lettergram 4y agoSeems this was only done on mice. Wouldn’t it be easy to evaluate (statistically) on males. Basically measure testosterone levels of out door laborers and indoor laborers. Then as a follow up have the indoor laborers go outside for 1 hr mid-day or something for 12 weeks and measure the effect.
- leni536 4y ago> Basically measure testosterone levels of out door laborers and indoor laborers. This is very susceptible to various biases.
- xnx 4y agoE.g.physical activity levels, body fat %, etc.
- sooheon 4y agoIf you skim the paper you will see they did multiple studies, including in humans. Including epidemiological studies and interventions like you mentioned. Which is why this is a well conceived paper, imo. Testosterone is increased for men living in areas with high UV radiation, but only during summer time. Proteins upstream of sex hormone production were upregulated after just a single day of 25m of bright midday sun exposure in both men and women.
- MaintenanceMode 4y agoWell, this is oddly personal for hackernews but what the heck. This is pretty interesting to me. I’ve been living outdoors for the last 12 months, and I’ve noticed some significant changes in libido. It’s been on my mind quite a bit (not only for the obvious reasons but also wondering why this is happening to me). There’s a lot of factors of course, going from a mostly sedentary indoor life to a mostly actively outdoor life but this is fascinating. My SO is much more careful than I am with UV exposure and hasn’t seen the same change but again, too many factors to control for in this sort of anecdotal experience.
- hh3k0 4y agoInteresting nonetheless, thanks for sharing! Slightly related: I've decided to stop using suncreen altogether for day-to-day sun exposure. My mood and overall sense of happiness increased significantly – in fact, it seemed to have helped more than my antidepressants ever did. (My libido did not increase but my antidepressants are pretty much libido killers.)
- axpy906 4y agoGot to watch out with sunscreen too. Many brands have ingredients that can pass the blood brain barrier.
- sizzle 4y agoShit like what??
- orangepurple 4y agoZinc oxide and titanium dioxide are the only two sunscreen ingredients the FDA considers truly safe sunscreen ingredients, and as someone with a basic understanding of biology, I tend to agree with them on this (1). Zinc oxide and titanium dioxide nanoparticles refuse to penetrate the skin even when rubbed into open wounds and they have negligible effects in vivo when used topically. Additionally and crucially they block UVA, the major skin cancer promoter, which won't give you sunburns. Zinc oxide is the most effective broad spectrum sunscreen. Titanium dioxide is less effective with UVA absorption. All other sunscreen compounds function after being absorbed into the skin. Unfortunately they also get into the bloodstream where they act as hormones such as estrogen mimickers (unintentionally). The only downside of zinc oxide and titanium dioxide is that they are awful to apply (you need a good technique) and you will probably look awful after application. It may be better to apply less material at a time but more often. Most manufacturers recommend every 80 minutes. I think this is defined by FDA regulation. Since zinc oxide and titanium dioxide are semiconductors, they can both reflect and absorb UV. I think there is a large gap in understanding by sunscreen manufacturers of how these nanoparticles perform on a quantum level. I hold out hope that some chemist can further engineer these nanoparticles perhaps through an innovative coating to further improve performance and appearance when applied. I think there is still a lot of money being left on the table and these compounds are under appreciated, not understood well, nor developed enough to this day. Fortunately the sunscreens containing them do work today. [1] https://www.fda.gov/media/153964/download https://www.fda.gov/media/153964/download
- Zenst 4y agoCertainly does corelate and will attest one's libido does increase in the Spring.
- Khelavaster 4y agoThis isn't big news at all. Melanocyte-stimulating hormones have been known to stimulate sexual behavior since forever. Melanocortin receptors directly modulate sexual behavior. Melanocyte-stimulating hormone production is boosted by from inflammatory effects of UV damage. This has been known forever, too.
- AuthorizedCust 4y ago> boosted by from inflammatory effects of UV damage That wording supports a notion that the boosting is to encourage the most essential activity of a species—reproduction—in the face of potential harms that may shorten the opportunity for that activity (cancer-induced final exit). That said, I’m aware of counterarguments to the simplistic takes on “sun bad” messaging and think they have merit. Not trying to open a debate on the latter, just clarifying that I’m not trying to grind an ax with the first paragraph.
- sdwr 4y agoThats what came to my mind too.
- whatshisface 4y agoThere's no way that we evolved to chemically respond to an effect that takes fifty years to happen.
- AuthorizedCust 4y agoEvolution is a long tail game. Over eons, any mutation conferring an increased likelihood of sustainable reproduction can “win”, including this one.
- deleted 4y ago[deleted]
- treeman79 4y agoSun exposure causes a severe inflammatory exposure for me. Spent a day at the beach and it was 7 months of burning nerve pain before I got it calmed down. Side effect of autoimmune Sjogrens. I don’t go out if UV is above a 2 anymore.
- immigrantheart 4y agoNot trying to be racist, but does this mean darker skinned people (caused by sun burn) are sexually more active?
- SamoyedFurFluff 4y agoSun burn doesn’t cause darker skin. Also being tan from sun exposure doesn’t have much to do with race. Melanin in the skin functions as a protectant against UV rays, so you would actually expect paler people to have more reaction to UV simply because they would have more exposure.
- jrexilius 4y agoAfternoon delight?...
- andrecarvalho 4y agoI’ve always joked that in summer I felt more “horny”. Guess I could’ve been into something.
- 1024core 4y agoDoes that mean a bulb like one of these would be useful for those of us stuck in foggy/cloudy climes (like San Francisco): https://www.amazon.com/s?k=uvb+reptile+light https://www.amazon.com/s?k=uvb+reptile+light
- felipelalli 4y agoAaaand... skin cancer.
- seydor 4y agoTime to invest in that maker of UVB bedroom lightbulbs
- Eleison23 4y ago
- MrYellowP 4y agoYet another piece of knowledge everyone should already be aware of, but apparently isn't.