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Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

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Re: Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

#81

Post by bruce343434 »

derefr wrote: post #27
numpad0 wrote: post #15

Earlier quoted context omitted.

I don't get how reduced UV exposure is supposed to be more attributable to sunscreens than to office labors. Most industrial materials block roughly 100% of UV rays, except viewing windows which allows as much as 1%. Therefore, just staying in any modern building alone cuts down UV exposure by 99% at very least. There is absolutely no way some translucent face painting does that.

People have been working white-collar jobs indoors behind UV-reflective windows for 50+ years now. Birth-rate decline — especially to below-replacement levels — begins much more recently than that; and is only happening in certain countries. The set of countries experiencing birth-rate decline is not 1:1 correlated with the set of countries with high/increasing white-collar employment; but, AFAICT, it is 1:1 correlat…

Isn't it a common phenomenon that smarter people have fewer children? Once you achieve high education people are more strategic about when, or if, to have children and how many.

Re: Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

#82

Post by sooheon »

mercy_dude wrote: post #7

Question: 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?

UVB exposure -> p53 activation -> downstream sex hormones upregulation is hypothesized to be mechanism, so sunscreen that blocks UVB will probably reduce the effect.

This study is part of an interesting trend I'm seeing of studies finding beneficial health effects to well timed, full spectrum sunlight exposure. The circadian benefits of seeing early morning sun every day (and darkness every evening) are well known. What's more surprising is that even UV exposure is not purely negative, and in the context of sunlight in moderate amounts (not to the point of acute sunburn) may be beneficial for health:

https://doi.org/10.1093/jnci/dji019 finds that high intermittent sun exposure actually decreases melanoma lethality. I.e. those who avoid the sun die more from melanoma.

https://doi.org/10.1111/joim.12251 found in a study that followed 30k women over 20 years that more sun exposure was associated with reduced all cause mortality. I.e. those who avoid the sun, apply more sunscreen die more in general.

Re: Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

#83

Post by leni536 »

lettergram wrote: post #78

Seems 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.

> Basically measure testosterone levels of out door laborers and indoor laborers.

This is very susceptible to various biases.

Re: Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

#84

Post by xnx »

leni536 wrote: post #83
lettergram wrote: post #78

Seems 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.

> Basically measure testosterone levels of out door laborers and indoor laborers. This is very susceptible to various biases.

E.g.physical activity levels, body fat %, etc.

Re: Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

#85

Post by suoduandao2 »

inglor_cz wrote: post #64
klodolph wrote: post #60

Earlier quoted context omitted.

I would normally be a bit skeptical of anything published by CSPI.

Given that American universities now routinely have a lot more administrators than teaching staff (still very untypical elsewhere in the world), wouldn't you at least agree that the bureaucratic bloat is real? This is, after all, what the students are paying in their tuition, which is becoming a major burden on the American middle class. (Ironically, "tuition" as a word promises that the money is mostly spent on teac…

politically I think it's more that in America, administrative positions skew heavily towards the political left in or outside Academia. There's a whole theory of analysing American politics based on the idea that the 'professional managerial class' (i.e. salaried administrative types) have interests that are better taken care of by the democratic party and vote accordingly.

I think the cognitive dissonance is more that administrative types want to think of their positions as necessary to the proper functioning of things.

Re: Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

#86

Post by sooheon »

lettergram wrote: post #78

Seems 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.

If 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.

Re: Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

#87

Post by sooheon »

amelius wrote: post #74

Would it make sense for a curious hacker to try out a narrowband UV-B lamp? https://www.proflamps.com/datasheets/Philips%20Phototherapy-...

There is a corner of the biohacking sphere for everything, including this:

https://getchroma.co/product/chroma-d-light/

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.

Re: Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

#88

Post by UpstandingUser »

pas wrote: post #48
totony wrote: post #26

"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?

https://www.cspicenter.com/p/its-time-to-review-the-institut... classic feature creep + bureaucratization (so it's now done by a special class of IRB administrators, not really by peers, etc)

Sounds like the Iron Law of Bureaucracy is at it again.

Re: Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

#89

Post by MaintenanceMode »

Well, 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.

Re: Skin exposure to UVB light induces a skin-brain-gonad axis and sexual behavior

#90

Post by adaml_623 »

amelius wrote: post #47

Bremelanotide, 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

Interesting 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]
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