[HN Gopher] Higher ultraviolet light exposure is associated with...
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Higher ultraviolet light exposure is associated with lower
mortality
Author : janandonly
Score : 67 points
Date : 2024-08-20 17:36 UTC (5 hours ago)
(HTM) web link (www.sciencedirect.com)
(TXT) w3m dump (www.sciencedirect.com)
| cpncrunch wrote:
| So I think now we can now say that the Lindqvist 2016 paper
| wasn't just a fluke. This is a real finding.
| api wrote:
| Is this more vitamin D evidence or is there something more going
| on?
| KennyBlanken wrote:
| I was under the impression that recent consensus was that
| Vitamin D supplementation has much less positive health impact
| than sunlight exposure?
| heroiccocoa wrote:
| Of course, there exists the whole field of
| photobiomodulation. Red light therapy
| (630/670/810/830/850/1060 nm red and NIR light) helps the eye
| in the morning (see Prof Glen Jeffery's work at UCL; the
| mitochondria are only sensitive to RLT during a certain
| window of the circadian rhythm, that coincides with early
| morning sunlight that is shifted towards the red/NIR),
| particularly when it comes to preventing and slowing age-
| related macular degeneration, but also improving colour
| perception, controlling blood glucose levels, improving
| athletic performance and recovery, mood and cognitive
| performance, and some other benefits. When I first got
| interested I thought I'd just get a small handheld LED
| device, but as I got deeper into it I decided to buy a large
| mains powered full body panel with 5 wavelengths. In
| particular the benefits to my sleep and skin have been
| fantastic, with the caveat that I live in northern Europe at
| a latitude of 53.3 degrees north. Perhaps those nearer the
| equator will feel more muted responses. That being said,
| improvements to vision are counterintuitively very difficult
| to actually judge without measuring, because the brain is
| constantly adjusting/hiding our defects.
| OutOfHere wrote:
| That is absolutely the right question to ask. If the results
| are not adjusted for vitamin D levels, and it does not appear
| that they are, then the results are largely useless because
| vitamin D is very easy to supplement.
|
| Note: Adjusting by vitamin D levels is _not_ the same as
| adjusting by supplemental intake. Even adjusting for
| supplemental intake must be a linear adjustment, not a binary
| one.
| jajag wrote:
| That's an overly simplistic approach.
| Mistletoe wrote:
| Vitamin d supplementation studies are a lot more ambiguous
| than this though. And this also matches my "feel". Getting
| sun makes me feel good in a way that vitamin D
| supplementation never does. I was once at a dinner and
| sitting at the table with the head of the Office of Dietary
| Supplements for the US government and asked him this
| question- "How should I get vitamin D and how much should I
| take?" He answered quite quickly "Get it from sunlight." Your
| skin autoregulates how much vitamin D is made this way.
|
| "The health effects of vitamin D supplementation: evidence
| from human studies"
|
| https://www.nature.com/articles/s41574-021-00593-z
|
| I do think the question is complicated by the fact that
| humans have wildly different skin tones. What is applicable
| for skin types that are very pale is quite different than
| darker skin tones. This question has been complicated even
| more by recent migration of humans into zones their skin was
| never meant to be exposed to. It feels like the
| dermatologists all made their guidelines based on people with
| porcelain skin that live at the equator. The truth is more
| complicated than that, people with darker skin develop low
| vitamin D status follwing those guidelines. Humans love to
| have blanket rules they can follow without regard to
| extenuating circumstances like different skin tones, but that
| isn't reality.
| OutOfHere wrote:
| > "Get it from sunlight."
|
| Listening to such people in power is a path to getting
| yourself killed, in this case by diseases. Their interest
| is in preserving their power, first by taking it away from
| you.
|
| They always have to say "don't supplement" because asking
| everyday people to supplement will force the officials to
| admit that the food and/or environment has recently been
| made inadequate. This will put the officials in a corner
| that they cannot get out of.
|
| The study you linked is defective by design. It uses a
| threshold of 50 nmol/l which is a pathetically low 20
| ng/ml. Such studies are engineered to show a null result.
| jajag wrote:
| The paper addresses this briefly, and suggests additional
| mechanisms to do with UV effects on different skin layers (e.g.
| NO mediated vasodilatation) may be involved.
| mcswell wrote:
| Did you (and those who so far responded to you) actually read
| the article? The Vitamin D question is addressed throughout,
| e.g. "Linear regression models were fitted for the UV exposures
| and vitamin D serum levels, adjusted for the same confounders
| for each UV exposure described above, plus vitamin D
| supplementation."
| OutOfHere wrote:
| > measured serum vitamin D levels, a biomarker for UV
| exposure,
|
| That's entirely the opposite of adjusting the results for
| vitamin D levels. It's biasing the results by vitamin D
| levels.
| EstanislaoStan wrote:
| So it's not just that people who go outside more are generally
| healthier: "Solarium users were also at a lower risk of non-
| CVD/non-cancer mortality."
| sokoloff wrote:
| I would wager that there's a positive covariance between
| "solarium users" and "not poor" where "not poor" is surely
| correlated with lower mortality.
| ljf wrote:
| Further discussion https://news.ycombinator.com/item?id=41301447
| waihtis wrote:
| I wonder how "moonbrah" Bryan Johnson will take this news
| Horffupolde wrote:
| So our body is best adapted to our natural environment where UV
| exposure is frequent. Scientists had their null hypothesis
| backwards.
| swalling wrote:
| Higher ultraviolet light exposure is associated with lower
| mortality... _for white people residing in the United Kingdom._
|
| The selected cohort of people is pretty specific from a global
| perspective. In particular, if you live in a higher UV location
| (i.e. closer to the equator), intentionally increasing sun
| exposure like they measured in this study may not be necessary or
| helpful. For instance, the entire lower 48 states in the USA are
| below the same latitude as the UK.
| mcguire wrote:
| Higher ultraviolet light exposure from:
|
| " _The UK Biobank has data from which behavioural and
| geographic UV exposures can be estimated. Firstly, participants
| were asked 'how many times a year would you use a solarium or
| sunlamp?' We recoded the responses to create a solarium use
| variable (solarium user or solarium non-user, defined as one or
| more times per year versus never or less than one time per
| year)._ "
|
| and
|
| " _Secondly, we estimated an annual average residential
| shortwave radiation (SWR; kJ /m2) over the follow-up period
| variable for each participant. Downward SWR is the total
| incoming solar energy over the Earth's surface in the shortwave
| spectrum and comprises both UVA and UVB radiation, (Yu et al.,
| 2021) the components solar radiation that have effects on human
| health. The Japan Aerospace Exploration Agency (JAXA)
| calculates half-monthly average of daily downward SWR (250
| nm-2500nm) measurements using daily data from the Moderate
| Resolution Imaging Spectroradiometer (MODIS) instrument on
| NASA's Aqua and Terra satellites, considering cloud and aerosol
| thickness (Murakami, 2010). These measurements are available at
| a 0.05degx.0.05deg spatial resolution._"
|
| So, "Did you use a sunroom at least once?" and "How much solar
| radiation does where you live according to our model?"
| mint2 wrote:
| Glad this was pointed out - 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 sun 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.
| xattt wrote:
| > 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.
|
| I observed a group of people going into a theme park at 5 PM
| and slopping on a thick layer of sunscreen. Sundown was ~8
| PM. Local UV index is essentially 0 at that time of the day.
|
| Mental models of UV exposure are not always intuitive.
| noncoml wrote:
| Higher calorific intake is associated with lower mortality*
|
| *Study conducted during the Great Famine
| hnlmorg wrote:
| While I get your point, I think it's a rather uncharitable
| way of putting it.
|
| A lot of the world is in lower UV continents like the UK.
| It's not like it's a statistical outlier like the great
| famine. So this research can have benefits to a lot of other
| people in other counties too.
| noncoml wrote:
| You are absolutely right about the research part.
|
| I guess I was surprised that it made it to the news, as it
| seems expected to me. If they would reach the opposite
| conclusion however, now that's newsworthy.
| arcticbull wrote:
| I mean, they would be the ones I'd expect to be the most
| sensitive to the negative impacts of UV radiation, right? The
| acute effects of UV tend to be worse on people who are (a)
| lighter skinned and (b) get less exposure in general.
|
| I would actually expect the biggest positive impacts would be
| to darker-skinned people who live in higher latitudes with more
| time spent inside (as melanin protects you from the UV
| radiation, so you see higher rates of, e.g. vitamin D
| insufficiency).
|
| There's three major pathways for health benefits from sun
| exposure.
|
| 1. UVB radiation stimulates the synthesis of vitamin D3.
|
| 2. UVA radiation stimulates the release of nitric oxide. This
| reduces your blood pressure and improves markers of
| cardiovascular health.
|
| 3. You're outside getting physical activity.
|
| [edit] Also note that melanoma survival rates are much better
| for people who get more time in the sun.
|
| [1] https://academic.oup.com/jnci/article/97/3/195/2544082
| jmward01 wrote:
| In his TED talk Weller points out that latitude correlates with
| heart disease well. This study gets to clear out a lot of
| variables by sticking to the UK though so it is really valuable
| in testing the potential of UV without having to deal with as
| many social/environmental/etc etc factors. It would have been
| nice if the paper mentioned the world data that shows
| correlation between cardio vascular disease and latitude to
| help put this study into better perspective. To sum it all up:
| There is a world trend but the data is a bit messy. This study
| took a smaller chunk of the world and the results support the
| world trend and the data is much cleaner.
| prbl2 wrote:
| This is an interesting finding. But, a reminder that this is
| epidemiological data. It is nearly impossible to "adjust" for all
| confounding variables in epidemiological studies. For example,
| you may expect a health user-bias among people who use solariums,
| sunlamps, or have high vitamin-D levels, and health at baseline
| might be effected by random fluctuations not accounting for all
| variance. I would look for evidence of randomized trials before
| taking this as the truth.
| marcosdumay wrote:
| How well fundamented is the opposite belief, that seems to be
| held as true by nearly everybody? I know the link to skin
| cancer is well established, but I don't know of any broad study
| about all causes of mortality.
|
| Yes, do not take this study as true. But also, look at your
| priors.
| arcticbull wrote:
| UV causes skin cancer - but the majority of them (10:1) are
| basal cell and squamous cell carcinomas. These have a 99-100%
| 5-year survival. While UV exposure can increase the risk of
| melanomas, it makes you less likely to die from them [1]. The
| UVA-mediated release of nitric oxide from the skin improves
| your cardiovascular health and you are far more likely to die
| of CVD than skin cancers, especially if you screen for them.
| Early stage melanomas have a 99.6% 5-year survival.
|
| [1] https://academic.oup.com/jnci/article/97/3/195/2544082
|
| Also note there is very limited evidence for the health
| benefits of vitamin D supplementation, especially if you're
| anywhere close to a normal level.
|
| [2] https://www.nature.com/articles/s41574-021-00593-z
| tannhaeuser wrote:
| As usual, correlation != causation. In this case, higher exposure
| to sunlight may just follow generally from more physical
| activity, and correlate with a healthier lifestyle. Asking the
| statistics champs here if such effects have been taken into
| consideration?
| ChrisArchitect wrote:
| [dupe]
|
| Discussion: https://news.ycombinator.com/item?id=41301447
| Havoc wrote:
| This smells like BS...or rather misdirection.
|
| If I go on a hike...and the health benefits of doing so are real,
| but I do incur a minor health negative from potential skin cancer
| from higher UV exposure.
|
| ...then I've still got a positive correlation between lower
| mortality and UV...even thought that's linking the wrong
| variables
| sokoloff wrote:
| Further, there's a selection bias in that those who choose to
| go on a hike today are not among the least healthy to start
| with, even if the hike itself didn't change anything.
| cpncrunch wrote:
| That doesn't explain the sunbed result. Also, Lundqvist did
| control for exercise in their 2016 study which gave the same
| result.
|
| The evidence base has been building for a long time, and I
| changed my own behavior over 10 years ago to get more UV. Not
| sure why you seem to feel the need to call it bs before even
| looking at the evidence.
| fimdomeio wrote:
| I have a very unscientific feeling that the scientific consensus
| will probably one day end up being something like:
|
| sun is good for you in moderation, the amount that is ok depends
| on your skin color, how tanned you get, in which part of the
| world you are and how often you are outside. Avoid too much sun
| and avoid sun burns and also avoid crazy strong sunscreens that
| block the benefits of getting sunlight. The lifestyle that some
| people have of spending the whole year inside in an office and
| that spending their all vacations roasting at the beach is very
| unhealthy because body does not have time to adapt.
| Unearned5161 wrote:
| quick! go to publishing before they beat you there!
| PaulKeeble wrote:
| This is the same thing as Vitamin D is good for health. Exposure
| to the sun is correlated with good health, the problem is the
| direction is the other way around healthy people are outside and
| in the sun more, hence they have higher Vitamin D levels.
| schappim wrote:
| I would have thought that exercise was the primary contributing
| factor, but the study isolated the effects of UV exposure by
| using independent UV measures, adjusting for confounders like
| exercise, employing a negative control outcome, and using
| directed acyclic graphs to identify and account for potential
| confounders.
| rich_sasha wrote:
| They do adjust for area wealth / deprivation etc. Even then I
| wonder if the "UV radiation" is just proxy for living up North
| and in cities, both of which lead to less solar irradiation and
| generally poorer health outcomes. E.g. healthcare coverage,
| unemployment, access to education etc. all get worse along a
| north-south axis.
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