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The health benefits of sunlight may outweigh the risk of skin cancer

economist.com

161–170 of 258 posts

Re: The health benefits of sunlight may outweigh the risk of skin cancer

#161

"The big picture is that the benefits of sunlight outweigh the risks—provided you don’t get sunburnt,” argues Richard Weller, a dermatologist at the University of Edinburg Also, Dr. Roger Seheult has some strong opinions on this as well. Considers sun exposure one of the pillars of health and avoiding the sun to be as dangerous as smoking.

That does seem to be the case. The Lindqvist study specifically said that sun avoidance was as bad as smoking iirc. Sun exposure has been one of my main activities for over 10 years. The evidence is now overwhelming.

Re: The health benefits of sunlight may outweigh the risk of skin cancer

#163
post #157

Earlier quoted context omitted.

Slathering oneself in mud if you need to endure harsh sun exposure is the most common answer I’ve seen to this question. Otherwise, I agree with your comment, the “best practice” of avoiding sun exposure is as unintuitive as the grain-heavy food pyramid.

That food pyramid hasn't been recommended in 20 years.

That’s my point.

Re: The health benefits of sunlight may outweigh the risk of skin cancer

#164
post #131

Earlier quoted context omitted.

time of day and UV index is the most important thing, right? That is how you can accurately assess the “risk” of being exposed in direct sunlight. Example: would you put on sunscreen when playing volleyball at the beach at 4:30pm, if the UV index at that time is 2 (UVI scale)? That seems completely unnecessary imo. And many people are vitamin d deficient anyway, so the minor sun exposure would certainly do more good.…

How reliable are UV indexes? Genuine question. The iOS weather app is far from 100% reliable and I wonder the margin of error regarding the UV index number it provides.

On cloudless days it it very accurate because on those days UV strength depends almost entirely on the solar altitude, which can be calculated very accurately from the location, the date and the time.

A sibling comment mentions the ozone layer, but I severely doubt it varies enough to be a source of inaccuracy.

Re: The health benefits of sunlight may outweigh the risk of skin cancer

#165
post #103

> A study published last year, for instance, examined medical data from 360,000 light-skinned Brits and found that greater exposure to UV radiation—either from living in Britain’s sunnier southern bits rather than the darker north, or from regularly using sunbeds—was correlated with either a 12% and 15% lower risk, respectively, of dying, even when the raised risk of skin cancer was taken into account. Emphasis on “m…

Sun good Science is good, but restraining all decisions behind FUTON biased double-blind longitudinal meta-analysis is not only unreasonably cognitiviely expensive, but not even the greatest idea. When making decisions to personally guide your life, you can also base them on values, heuristics, paternal advice, common wisdom, etc... It's obvious that the ideal amount of sunlight is somewhere between 0 and 100% of the…

Yeah, I agree. This always seemed pretty obvious to me but it was also obvious that it's nuanced and can be highly variable depending on skin type, medical history, locale, lifestyle and preferences.

But when it comes to things which are very probably "mostly beneficial for most people most of the time - but (obviously) not always beneficial for all the people all the time", there's a reluctance to say anything unless you've got study data to fully support everything you say into "the nines". But the world is full of things that are hard, expensive or impossible to study experimentally with that kind of rigor.

Re: The health benefits of sunlight may outweigh the risk of skin cancer

#166

dunno man, just had melanoma removed from my ear and if it had moved to my lymph nodes I had a 50% chance of dying within 5 years. thankfully it didn't but it was caused by sun damage incurred in my youth. I'll be wearing sunscreen and mostly avoiding direct sunlight.

There are studies that show that regular sun exposure is correlated with both lower incidence of and lower mortality from melanoma.

So as long as you're not getting sum burns, sun exposure is actually better for you.

In some decades we'll look at the whole sun avoidance policy as those doctors prescribing cigarettes a century ago.

Re: The health benefits of sunlight may outweigh the risk of skin cancer

#167
post #131

Earlier quoted context omitted.

time of day and UV index is the most important thing, right? That is how you can accurately assess the “risk” of being exposed in direct sunlight. Example: would you put on sunscreen when playing volleyball at the beach at 4:30pm, if the UV index at that time is 2 (UVI scale)? That seems completely unnecessary imo. And many people are vitamin d deficient anyway, so the minor sun exposure would certainly do more good.…

How reliable are UV indexes? Genuine question. The iOS weather app is far from 100% reliable and I wonder the margin of error regarding the UV index number it provides.

I am in a unique position to confirm that they are a load of bunk. I have solar urticaria and develop hives in response to UV exposure, directly proportional to how much UV is getting through. I’ve developed hives in minutes while the UV index was supposedly only 4 and gone for relatively too long without erupting in hives the next day even when the UV index was supposedly 10.

Re: The health benefits of sunlight may outweigh the risk of skin cancer

#168

It’s tempting to see things like this and think “well of course it does, because that’s how we evolved”. But I think that might just be post-rationalization? At the very least, I think the argument _doesn’t_ hold for periodic famine, extreme temperatures, most disease, etc even though we also evolved with those things. Is there any guiding principle that separates the things-we-evolved-with-that-are-good vs the -that…

Exactly - as if evolution cared enough about keeping us healthy after childbearing age. It's hard to state "yeah we've evolved to live like that, of course it's good for us" because clearly keeping us alive after the age of 40 really wasn't _that_ necessary for human survival. There's a lot of perfectly natural stuff that hurts us, including sunlight. Most cancers will only occur in the latter half of our lives, wher…

> because clearly keeping us alive after the age of 40 really wasn't _that_ necessary for human survival.

That's a very common misconception. Being alive after 40 is quite necessary if you are a member of a gregarious species that (bar exceptions) always lives in community. And it's not only about the survival of your own genes, it's about the survival of the genes of the whole community.

Re: The health benefits of sunlight may outweigh the risk of skin cancer

#169

Earlier quoted context omitted.

Since I was a little kid I was always skeptical of slathering something all over my body just to go outside. Just thought…how did people survive before this stuff if we really need it so bad.

People didn't used to expose themselves to as much direct sun and covered themselves with a lot more clothes. Traditional clothing in arid sunny areas typically covers everything, look at people in the middle east today. I live in a very sunny desert area and it's kind of funny when people assume people from here would be "more tanned". We stay in the shade, the sun will kill you! Anyone working outside is wearing wi…

People in greece/israel/italy/etc don't cover themselves much and they have very long lives.

Re: The health benefits of sunlight may outweigh the risk of skin cancer

#170
I think people should be highly skeptical of articles like this, even without knowing anything about the subject in question. No byline/author. No citations/links to the studies in question. Confirmation of preconceived notions that people would like to be true (e.g. the sun as a wellness remedy instead of damaging to skin), including unfounded "just so" stories and claims about evolution, diabetes, and other unrelated topics. Named individuals seem to "specialize" in sunlight as a wellness remedy (seems like a big red flag to me). No actual physical theory as to how it could be true (more vitamin D reduces death by up to 50%? how? your body only needs so much vitamin D and it's not actually all that much).

And sure enough, if you look up any details on the studies in question, they are highly questionable. Vastly different populations studied with very weak controls. For example, sunscreen use -- both chemical and physical, i.e. hats -- was not controlled for. Seems like a big problem since that's the primary claim being made! And it seems like such an obvious thing. It makes one wonder why it was omitted.

The facts of the "status quo" of sun exposure dangers, on the other hand, have quite a lot more going for them, both in terms of study quality and in terms of physical explanation/interpretation. UV radiation physically damages DNA, even when you don't burn. Tanning is a response to skin cell damage, so any additional melanin production in your skin is indication that your DNA is being damaged. Damaged DNA means when your cells reproduce, they reproduce the damage and/or otherwise mutate. If that damage or mutation happens to be cancerous, then you have a big problem. Tanning, contrary to what people seem to think, doesn't inoculate you against skin cancer or damage. It merely helps absorb a higher percentage of UV radiation -- meaning your skin is still getting damaged, just at a slightly lower rate (a helpful, though marginal, evolutionary advantage).

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