1. Research shows the most popular vitamin supplements aren't useful. This turns out to include D supplements.
2. This is strange because "People with low levels of vitamin D in their blood have significantly higher rates of virtually every disease and disorder you can think of"
3. One theory to explain this is that Vitamin D was acting as simply a marker for sun-exposure. This is put forth by Richard Weller.
4. To add evidence, Weller found that exposing people to sunlight for 30 minutes reduced blood pressure and increased nitric oxide levels.
5. Article dispells concerns about sun exposure by pointing that the type of skin cancer one is likely to get from the sun is actually very safe (carcinomas) as compared to melanoma (1-3% of cases).
6. Cites a study 30,000 Swedish sunbathing women and found greater health and decreased odds of dying from a melanoma.
7. Observes the counter-intuitive nature of sun-exposure being harmful to a species that evolved outdoors.
8. Questions the validity of SPF recommendations when they don't factor in race / skin-tone.
9. Observes an example of "common knowledge" being wrong with margarine which was wrongly perceived to be healthier than butter for a long time. Suggests the very thing may be happening here.
2. Regular safe sun exposure has many positive benefits and very few negatives (a very very small chance of getting a type of cancer that is normally deadly, but for reasons we don't fully understand, is much less deadly to people who get regular sun exposure).
3. Avoiding sun exposure entirely has many negative effects and will kill you.
4. Intermittent extreme sun exposure (the kind that causes sunburn) actually is terrible, and will lead to the bad skin cancers that will actually kill you.
5. Sunscreen may do more harm than good, both to people and the environment. It's certainly not a magic bullet.
6. Sun exposure needs (and risks) vary heavily by skin colour, and while it's good for everyone to get regular safe sun exposure, it's critical for people with darker skin.
In other words, if (like a lot of Americans) you take vitamin D supplements, avoid the sun most of the year, then slather on a ton of sunscreen for your once a year summer vacation, you're basically doing everything as wrong as you possibly can, and getting the worst of all worlds.
And apparently this is supported by new research, and most countries have already adopted it, with the main outlier being the US, primarily due to industry pressure/greed/inertia.
> then slather on a ton of sunscreen for your once a year summer vacation, you're basically doing everything as wrong as you possibly can, and getting the worst of all worlds.
Agreed but Sunscreen might still be better in that case. See point 4 (Intermittent extreme sun exposure (the kind that causes sunburn) actually is terrible). These people would be sure to get bad sunburn if they lay on the beach all day only 2 weeks out of the year.
Of course, even if unhealthy sun exposure + sunscreen is better than unhealthy sun exposure on its own, it doesn't mean it's better than avoiding the unhealthy sun exposure patterns at all.
I feel like there's a fair bit more to figure out here. A lot of us live far from the equator with jobs and hobbies that keep us indoors a lot. Observing that regular safe sun exposure is healthy is great, but I don't even like beaches. It's easy to criticise bad ideas (vitamin D supplements, tanning beds, etc.) but harder to figure out the best compromise.
As a general principle, 7 does not seem valid (consider the case of sugar consumption). Life expectancy has increased and causes of death have changed. Cancer is now a much greater issue, while diseases of malnutrition are rare in the developed world.
Given that melanoma is so rare, it might be valid in this particular case, but it absolutely makes sense that sun exposure could have a mixture of positive/negative effects in prehistoric times, but a different mix today.
Another factor that's relevant to some of us: as someone of Northern European descent living in the southern US, I'm not in the environment that selected for my pale skin (and my ancestors didn't wear t-shirts in February). This effect might go in the opposite direction for dark-skinned folks living in Northern Europe.
I have very light skin and red hair. My kids have mid range skin, and half their genes come from near the equator. I find it incredible that the pediatrician's recommendations for sun exposure and sunscreen are identical for them as they were for me. Especially since every person in my wife's family who lives far from the equator is vitamin D deficient.
The reduction of sun exposure is vicious -- for white people, especially pasty-white hackers like me, it can only take a few minutes to burn. So the medical community recommends we stay inside and lather up to stay pasty. And take a "pharmacopoeia" for the resulting depression, hypertension, cancer, reduced disease immunity...
But if I spend time outdoors year-round, my skin takes on an olive tone, my freckles get darker, and when summer comes around I can enjoy the sun without fear of burns. But that's free health care, and the medical industry makes money hand over fist with that pharmacopoeia.
I'm going to give the medical community the benefit of the doubt here, and particularly, the dermatological community. Skin cancer is something in their domain, and so of course it's a big deal for them, but I think they're missing the forest for the trees.
The other side of the argument is that you might not have visible burns, but you are still being exposed to high-energy radiation that will damage the DNA of skin cells, making you more prone to skin cancer. This risk can be somewhat mitigated by going for regular skin checks as you age. All things taken into consideration, I'm also in the "have fun in the sun" camp.
Prehistoric humans were under a hell of a lot more environmental and physical stress than we are. Being healthier, not dying later, is going to be the objective of evolutionary pressures during that time.
> 7 does not seem valid (consider the case of sugar consumption)
How much refined sugar do you think people were eating in the environment of evolutionary adaptation?
(Although, I agree that causes of death change as life expectancy changes, and things that didn't matter before start to matter now that the low-hanging fruit has been picked)
The issue is that people nowadays may live in a place with a lot more UV than their ancestors adapted to -- consider an Irish family that moved to Arizona, for example. The same principle of "more available than evolution prepared you for" seems also to apply.
I don't think "refined" matters, except so far as once you refine sugar, you can add it to all kinds of foods, driving consumption up. That's exactly my point--eating some fruits or honey is good for your health when every calorie is valuable. Eating tons of sugar when it's cheap and added to everything is bad for your health. Just because eating some sugar was helpful in the past doesn't imply that our bodies have evolved to process arbitrarily large amounts of sugar with no ill effects whatsoever.
To add some "anecdata" to the discussion, vitamin d supplements changed my life. I learned that my vitamin d levels were super low (7 ng/ml, when less than 20 ng/ml is deficient) from a routine blood test. Within a month of taking vitamin d, my afternoon fatigue went away, it became much easier to wake up in the morning, my energy levels generally increased, and my mysterious colds that I was getting every 1-2 weeks that winter stopped.
I strongly recommend getting your vitamin d levels checked!
Yes, I had low levels as well in the winter only, and supplements made a big difference in my mood in the winter (and I verified my levels were back to a normal zone).
So while these studies may be showing that vitamin D doesn't affect cancer, heart disease or strokes... that doesn't mean it's useless. YMMV.
"Most people can make enough vitamin D from being out in the sun daily for short periods with their forearms, hands or lower legs uncovered and without sunscreen
...
you should be careful not to burn in the sun, so take care to cover up or protect your skin with sunscreen before your skin starts to turn red or burn.
People with dark skin ... will need to spend longer in the sun to produce the same amount of vitamin D as someone with lighter skin."[0]
First of all, thanks, your summary is literally better than the article itself :-)
P.1 is not correct (it correctly reflects the article contents, but not factually correct). Research mentioned states vit. D supplements doesn't seem to reduce risks of cancers, and cardiovascular diseases - which doesn't mean they aren't useful.
5 is not quite right. According to the article, your melanoma risk does rise with sun exposure, but for some reason that is not explained, you are substantially less likely to die from it if you have more sun exposure. The article does not clarify how much the incidence increases though, and whether it offsets the 8-fold decrease in mortality.
I thought the article mentioned early on that the issue are sunburns. If for example you are a pastry, white person usually hacking indoors and then you suddenly go on vacation in the Caribbean and are in the sun without protection or adjustment period, that's a problem. If on the other hand you get a reasonable amount of sunlight year around that's what supposedly leads to better health outcome.
With regard to sunbathing in Sweden, it sounds like the study was originally designed to track many variables for possible influence on blood clots. Tanning behavior ended up having a high correlation with lower all-cause mortality. I haven't looked into whether they controlled for variables like socioeconomic situations that allow for more suntanning, though that seems likely before publishing such a conclusion. What seems less likely to have been controlled when just looking for contributors to blood clots, would have been whether the subjects' skin tanned easily.
Many light-skinned people do not easily tan at all, and even complain that their skin seems to go straight from white to red. In Sweden, there are many people who do tan easily in spite of having very light skin. It seems like that could very easily have been a confounding factor. The genes that make you bun easily or tan easily seem like they would have a significant effect on ones decision on whether to sunbathe or not. Likewise, I can imagine that those genes could also affect all-death mortality rates.
personally I used to burn pretty easily (light skin, freckles) When I was much younger and spent most my time indoors. However I took up multiple outdoor activities and after quite some time in the sun it’s rare for me to burn even after hours in the sun with no sunscreen, and if I do burn it heals fairly rapidly.
So outside genes there may be some sort of adaptation going on.
True. Another thing to consider is that regardless of the health effects, sun exposure ages your skin; sometimes dramatically so.
A compromise would be to use sunscreen on your face and neck (since they don't produce that much vitamin D anyway, if I'm remembering a study correctly), but leave the rest of your body uncovered. Perhaps add sunscreen to your hands too.
It usually goes as "Vitamin D is not useful for healthy individuals" which is a nice example of circular reasoning (probably because they get enough sun exposure or have good levels of Vit. D from other sources)
Oh yeah and tests checking Vitamin D's effects on things it was never claimed to help, like "found no impact on cancer, heart disease, or stroke." (Maybe cancer, but still)
You will still get some Vit D through sun even with sunscreen on
> Yes, but skin cancer kills surprisingly few people: less than 3 per 100,000 in the U.S. each year.
Tell that to people in Australia or some other country directly below the Ozone layer hole
But the news that production of NO is more important than Vit D is certainly interesting
Yep and that's a UV index of 13 [Extreme] even whilst cloudy.
Australia and New Zealand have the highest melanoma rates in the world. We thus have a paranoia of "taking care not to burn", during office hours when UV is most intense.
The problem here is that UVB levels, required for vitamin D synthesis, decrease dramatically before 9am and after 6pm, whereas UVA does not. The best option for vitamin D synthesis is short sun exposure around midday.
That's a misconception, if I remember correctly. The ozone layer is over Antarctica. UV levels here (Australia) are high because the air is quite dry and clean (so I have heard). During summer (i.e. now) the UV index reaches 13 daily.
That's literally the first time I see that visualisation. Check this out:
Does the Antarctic Ozone Hole ever come over Australia?
No. The ozone hole has only ever been observed to be well south of the Australian mainland and Tasmania. In fact, during springtime, when the hole is in existence, ozone levels over southern Australian cities are at their highest.
It surprises me that people believe that margarine, a concentrate of vegetable raffinates fats, is healthier then butter.
I believed it was common knowledge how bad margarine is for our body... at least in Italy, where we always use olive oil of butter - I don’t know anybody that would prefer margarine here!
1. Research shows the most popular vitamin supplements aren't useful. This turns out to include D supplements.
2. This is strange because "People with low levels of vitamin D in their blood have significantly higher rates of virtually every disease and disorder you can think of"
3. One theory to explain this is that Vitamin D was acting as simply a marker for sun-exposure. This is put forth by Richard Weller.
4. To add evidence, Weller found that exposing people to sunlight for 30 minutes reduced blood pressure and increased nitric oxide levels.
5. Article dispells concerns about sun exposure by pointing that the type of skin cancer one is likely to get from the sun is actually very safe (carcinomas) as compared to melanoma (1-3% of cases).
6. Cites a study 30,000 Swedish sunbathing women and found greater health and decreased odds of dying from a melanoma.
7. Observes the counter-intuitive nature of sun-exposure being harmful to a species that evolved outdoors.
8. Questions the validity of SPF recommendations when they don't factor in race / skin-tone.
9. Observes an example of "common knowledge" being wrong with margarine which was wrongly perceived to be healthier than butter for a long time. Suggests the very thing may be happening here.