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

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).

Sure but you should also be highly skeptical of people telling you that sunscreen is always required to go outside. A lot of the studies are funded by sunscreen companies which stand to make a lot of money.

> Tanning is a response to skin cell damage

I don't think this is true in any meaningful sense. Damage is part of life. Your body repairs minor damage and it is usually a good thing to trigger the repair pathways once in a while. This is also the basis for exercise - your muscles and tendons are damaged when you work out, but they get rebuilt stronger. Your DNA is also repaired, and turning repair pathways on can sometimes improve tissue quality/collagen production or get rid of imperfections - this is the basis of microneedling and cosmetic techniques, some of which involve light exposure. UV therapy is also a treatment for psoriasis (skin inflammation).

If any amount of sunlight is bad, ask yourself why melanoma typically occurs on the trunk region (in men) or legs (women) rather than say the face or arms. Those are regions that are normally hidden, but are then suddenly exposed when you go shirtless/at the beach.

The most dangerous thing is to go straight from non-exposure to high exposure. But if you gradually increase exposure, the body has many ways of dealing with non-overwhelming amounts of damage. Damage can in fact trigger repair which is often beneficial, as this article alludes to.

Most importantly, the more beneficial UV rays (UVB) for vitamin D production are weaker than the more harmful ones (UVA), so any sunscreen or glass that "blocks UV" necessarily blocks all UVB before you get close to blocking all UVA. Nothing can actually block 100% of UVA. But let's say you slather sunscreen on every time you go out. Now imagine one day you forget it or run out of it or for whatever emergency reason can't apply it. Now your pale unready skin is exposed to a large dose which could actually do more damage than your body is ready to repair.

The best time to get UVB is actually around solar noon. So, depending on your skin type, the best thing to do is to expose yourself to sunlight for short amounts of time (start with 1 minute if you want) without sunscreen before applying sunscreen. Then gradually increase the non-sunscreen time as your skin turns up repair pathways (and you get tanner).