4 ms·

No, because they have a demonstrable mechanism from pre-established science: UV radiation damages DNA, which causes cancer. Their product absorbs or scatters U

No, because they have a demonstrable mechanism from pre-established science: UV radiation damages DNA, which causes cancer. Their product absorbs or scatters UV radiation. This is the same as the teeth flossing skeptics: observational studies suggesting a paradox are interesting, but they actually need to unearth convincing alternative models with at least as much support as the dominant one for why they're right.

deleted 4y ago
[deleted]
taeric 4y ago
This feels wrong, too. You are presenting one option as a settled thing because it has a proposed mechanism. I agree that just dropping a seemingly safe belief should take effort. I have no problem challenging them on a regular basis, though. Especially with more than just arguments and thought experiments. More observational studies can almost certainly only be a good thing.
- dsizzle 4y ago
  GP didn't say that the science of sun exposure is "settled." Also, that UV damages DNA and causes cancer isn't simply a "proposed" mechanism, it's been tested many times. I would say pure "observation" per se has little value -- for it to be scientifically valid it needs to seek explanations.
  - taeric 4y ago
    Observational studies are certainly science. Any claim against that is going to be hard to defend. The mechanism isn't really at question. But just as sun exposure can kill grass, so to can lack of sun. We know that humans don't do photosynthesis, but it seems reasonable to ask if we do get other benefits. Note. Is reasonable to ask and study. Is not reasonable to just assume the conclusion.
    - dsizzle 4y ago
      By "observational" studies I realize you probably just meant studies where they don't manipulate a variable (which, while less than ideal, it is indeed science), whereas I was making a more philosophical point, a la Popper https://www.goodreads.com/quotes/778918-the-belief-that-science-proceeds-from-observation-to-theory-is https://www.goodreads.com/quotes/778918-the-belief-that-scie...
      - taeric 4y ago
        Ah, makes sense. You are correct in what I was referencing. To your point, I would expect most observational studies to be done with the expection of validating understood mechanisms.
dsizzle 4y ago
The article did describe some mechanisms, for instance the skin uses UV to make nitric oxide, which is known to lower blood pressure. That said, I'm not sure why this would be better than just taking nitric oxide. The same question comes up for vitamin D, and it's noted that supplements don't seem to help there -- with no explanation for that. So I would agree that the explanations for the pro-sunlight case are weaker.
- JohnBooty 4y ago
  That said, I'm not sure why this would be better than just taking nitric oxide One might do well to start with the assumption that "taking XYZ orally" is not as effective as producing it naturally. The digestive system involves a pit of acid and a diverse, poorly-understood, and variable biome. It is an extremely fraught and indirect way to introduce substances into the body. Obviously many things can be introduced this way, but the list of those that can't is probably longer than the list of things that can.
  - iostream24 4y ago
    Not to mention that one of the premises of the article was that vitamin d levels were a marker, not some singular responsible agent.
    - dsizzle 4y ago
      The conclusion that vitamin D levels are an effect not a cause came from exploring the mechanisms. And yes, it may turn out that NO similarly is a marker. It's ironic that the author didn't consider that getting sunlight may similarly be the side effect of the true cause of the stated benefits (being active?).
      - lr4444lr 4y ago
        It may be, but NO itself is also very much a vasodilator, and used therapeutically for that.
  - 4y ago
ivan_gammel 4y ago
> No, because they have a demonstrable mechanism from pre-established science: UV radiation damages DNA, which causes cancer. Their product absorbs or scatters UV radiation. As mentioned in article, but also some general knowledge in physics is that interaction of radiation with the matter is probabilistic. It is not like every quantum of UV radiation will always damage DNA, which always result in cancer. There's some "conversion funnel" that depends on a number of parameters, and the actual probability of cancer in the end could indeed be lower than probability of the negative consequences of low sun exposure. Even if physical mechanism of diseases is established, it does not mean we should always avoid the risk by disabling it by some expensive means. Sometimes it is low enough to accept it or mitigate (e.g. by efficient cancer treatment).

deleted 4y ago

[deleted]

taeric 4y ago

This feels wrong, too. You are presenting one option as a settled thing because it has a proposed mechanism. I agree that just dropping a seemingly safe belief should take effort. I have no problem challenging them on a regular basis, though. Especially with more than just arguments and thought experiments. More observational studies can almost certainly only be a good thing.

dsizzle 4y ago
GP didn't say that the science of sun exposure is "settled." Also, that UV damages DNA and causes cancer isn't simply a "proposed" mechanism, it's been tested many times. I would say pure "observation" per se has little value -- for it to be scientifically valid it needs to seek explanations.
- taeric 4y ago
  Observational studies are certainly science. Any claim against that is going to be hard to defend. The mechanism isn't really at question. But just as sun exposure can kill grass, so to can lack of sun. We know that humans don't do photosynthesis, but it seems reasonable to ask if we do get other benefits. Note. Is reasonable to ask and study. Is not reasonable to just assume the conclusion.
  - dsizzle 4y ago
    By "observational" studies I realize you probably just meant studies where they don't manipulate a variable (which, while less than ideal, it is indeed science), whereas I was making a more philosophical point, a la Popper https://www.goodreads.com/quotes/778918-the-belief-that-science-proceeds-from-observation-to-theory-is https://www.goodreads.com/quotes/778918-the-belief-that-scie...
    - taeric 4y ago
      Ah, makes sense. You are correct in what I was referencing. To your point, I would expect most observational studies to be done with the expection of validating understood mechanisms.

dsizzle 4y ago

The article did describe some mechanisms, for instance the skin uses UV to make nitric oxide, which is known to lower blood pressure. That said, I'm not sure why this would be better than just taking nitric oxide. The same question comes up for vitamin D, and it's noted that supplements don't seem to help there -- with no explanation for that. So I would agree that the explanations for the pro-sunlight case are weaker.

JohnBooty 4y ago
That said, I'm not sure why this would be better than just taking nitric oxide One might do well to start with the assumption that "taking XYZ orally" is not as effective as producing it naturally. The digestive system involves a pit of acid and a diverse, poorly-understood, and variable biome. It is an extremely fraught and indirect way to introduce substances into the body. Obviously many things can be introduced this way, but the list of those that can't is probably longer than the list of things that can.
- iostream24 4y ago
  Not to mention that one of the premises of the article was that vitamin d levels were a marker, not some singular responsible agent.
  - dsizzle 4y ago
    The conclusion that vitamin D levels are an effect not a cause came from exploring the mechanisms. And yes, it may turn out that NO similarly is a marker. It's ironic that the author didn't consider that getting sunlight may similarly be the side effect of the true cause of the stated benefits (being active?).
    - lr4444lr 4y ago
      It may be, but NO itself is also very much a vasodilator, and used therapeutically for that.
- 4y ago

ivan_gammel 4y ago

> No, because they have a demonstrable mechanism from pre-established science: UV radiation damages DNA, which causes cancer. Their product absorbs or scatters UV radiation. As mentioned in article, but also some general knowledge in physics is that interaction of radiation with the matter is probabilistic. It is not like every quantum of UV radiation will always damage DNA, which always result in cancer. There's some "conversion funnel" that depends on a number of parameters, and the actual probability of cancer in the end could indeed be lower than probability of the negative consequences of low sun exposure. Even if physical mechanism of diseases is established, it does not mean we should always avoid the risk by disabling it by some expensive means. Sometimes it is low enough to accept it or mitigate (e.g. by efficient cancer treatment).