Higher ultraviolet light exposure is associated with lower mortality(sciencedirect.com)
sciencedirect.com
Higher ultraviolet light exposure is associated with lower mortality
https://www.sciencedirect.com/science/article/pii/S1353829224001564
54 comments
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.
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.
> 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.
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.
> Mental models of UV exposure are not always intuitive.
100%. On this front, the study notes something important that helps explain the lower overall mortality, which is that "Most melanoma is a disease of intermittent burning sun exposure, particularly in childhood."
In other words, skin cancer doesn't increase exponentially with total lifetime UV exposure, unlike say, regular alcohol use or smoking. It's much riskier to get burned repeatedly in early childhood than it is to have regular moderate levels of sun exposure long term while avoiding being burned.
100%. On this front, the study notes something important that helps explain the lower overall mortality, which is that "Most melanoma is a disease of intermittent burning sun exposure, particularly in childhood."
In other words, skin cancer doesn't increase exponentially with total lifetime UV exposure, unlike say, regular alcohol use or smoking. It's much riskier to get burned repeatedly in early childhood than it is to have regular moderate levels of sun exposure long term while avoiding being burned.
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 0.05°x.0.05° spatial resolution."
So, "Did you use a sunroom at least once?" and "How much solar radiation does where you live according to our model?"
"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 0.05°x.0.05° spatial resolution."
So, "Did you use a sunroom at least once?" and "How much solar radiation does where you live according to our model?"
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.
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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
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
Higher calorific intake is associated with lower mortality*
*Study conducted during the Great Famine
*Study conducted during the Great Famine
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.
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.
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.
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.
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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.
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.
> avoid crazy strong sunscreens
It's also known that sun exposure causes the vast majority of visible skin aging. So I choose to use overkill sunscreen on my face and neck to preserve my youth and balance that out by using no sunscreen on my legs. In the summer, running around in shorts, I should get plenty of sun. In the winter, I supplement vitamin D anyway
It's also known that sun exposure causes the vast majority of visible skin aging. So I choose to use overkill sunscreen on my face and neck to preserve my youth and balance that out by using no sunscreen on my legs. In the summer, running around in shorts, I should get plenty of sun. In the winter, I supplement vitamin D anyway
Vitamin D is one of those substances few in number that the human body should synthesize (at all / more of) but doesn't.
quick! go to publishing before they beat you there!
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."
So our body is best adapted to our natural environment where UV exposure is frequent. Scientists had their null hypothesis backwards.
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.
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.
Yes, do not take this study as true. But also, look at your priors.
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
[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
It’s a travesty that darker skinned people living in northern latitudes are being marketed sun screen. They need extra exposure to get sufficient vitamin D generation.
(This is one strong correlate for higher levels of obesity in these communities).
Can't they just tale vitamin D supplements? Why extra exposure?
Vitamin D is probably not the only benefit derived from sun exposure:
https://www.nature.com/articles/s41598-023-43653-2#:~:text=L....
https://www.nature.com/articles/s41598-023-43653-2#:~:text=L....
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.
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Imagine this was controlled not only for Vitamin D but for physical activity
[dupe]
Discussion: https://news.ycombinator.com/item?id=41301447
Discussion: https://news.ycombinator.com/item?id=41301447
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.
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.
So I think now we can now say that the Lindqvist 2016 paper wasn't just a fluke. This is a real finding.
Further discussion https://news.ycombinator.com/item?id=41301447
Is this more vitamin D evidence or is there something more going on?
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."
> 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.
That's entirely the opposite of adjusting the results for vitamin D levels. It's biasing the results by vitamin D levels.
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.
I was under the impression that recent consensus was that Vitamin D supplementation has much less positive health impact than sunlight exposure?
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.
Hi, do you happen to have to have some resources for someone interested in using red light therapy? Or even just a simple buying tip to get started. As someone with quite high myopia and a little bit of astigmatism thrown in, I'm at higher risk of myopic macular degeneration, so red light therapy might be extra useful!
I'm only seeing this now, sorry. First I'm not a doctor, so I can't give medical advice, certainly not if you believe you are already predisposed to something. I would say that there is no difference between the cheap and expensive devices, as long as they emit the correct wavelengths at the correct intensities. Since that's very low for targeting the eye (you are not trying to treat deeper joints/full body), you won't have to overspend. I think Prof Glen Jeffery mentioned a handheld red light in the 30 euro range for the morning treatment.
You can also look at (670/810 nm LED light strips to hang above your computer monitors and passively absorb some while starting at your monitor all day if you are getting an excess of blue light). I think that is another protocol though, but it might help.
I am sure though that it's more about consistency and treatment time (as in, you can't double the intensity to halve the treatment time). Furthermore, more is not better, it's more like an on/off switch after 2-3 minutes. You can do it every day, just like the solar spectrum is relatively higher in the required part of the spectrum at early morning sunrise every day.
But honestly, listen to Glen Jeffery, perhaps read /r/redlighttherapy
You can also look at (670/810 nm LED light strips to hang above your computer monitors and passively absorb some while starting at your monitor all day if you are getting an excess of blue light). I think that is another protocol though, but it might help.
I am sure though that it's more about consistency and treatment time (as in, you can't double the intensity to halve the treatment time). Furthermore, more is not better, it's more like an on/off switch after 2-3 minutes. You can do it every day, just like the solar spectrum is relatively higher in the required part of the spectrum at early morning sunrise every day.
But honestly, listen to Glen Jeffery, perhaps read /r/redlighttherapy
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.
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.
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.
"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.
> "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.
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.
[deleted]
That's an overly simplistic approach.
There are specific medical conditions that respond well to uv exposure (perhaps through mechanisms like apoptosis and changes to the immune system) that don't benefit much from vitamin D supplementation. I would be wary about assuming those benefits can be generalized or outweigh the known risks of uv exposure. People who spend more time outdoors likely have more physically active lives, are less exposed to VOCs and infections and there could be many demographic differences that are hard to control.
I wonder how ”moonbrah” Bryan Johnson will take this news
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
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
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.
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.
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.
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?
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.