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There's No Such Thing as a Safe Tan (theconversation.com)
H. Peter Soyer, Professor of Dermatology, and Katie Lee, Research assistant at The University of Queensland, write: There's a lot to be said for sunshine -- both good and bad. It's our main source of vitamin D, which is essential for bone and muscle health. Populations with higher levels of sun exposure also have better blood pressure and mood levels, and fewer autoimmune diseases such as multiple sclerosis. On the other hand, excess UV exposure is estimated to contribute to 95% of melanomas and 99% of non-melanoma skin cancers. These skin cancers account for a whopping 80% of all new cancers each year in Australia.
Like any medicine, the dose counts. And in Australia, particularly in the summer, our dose of UV is so high that even short incidental exposures -- like while you hang out the washing or walk from your carpark into the shops -- adds up to huge lifetime doses. Fortunately, when it comes to tanning, the advice is clear: don't. A UV dose that's high enough to induce a tan is already much higher than the dose needed for vitamin D production. A four-year-long study of 1,113 people in Nambour, Queensland, found no difference in vitamin D levels between sunscreen users and sunscreen avoiders. Further reading: Is Sunscreen the New Margarine?
Like any medicine, the dose counts. And in Australia, particularly in the summer, our dose of UV is so high that even short incidental exposures -- like while you hang out the washing or walk from your carpark into the shops -- adds up to huge lifetime doses. Fortunately, when it comes to tanning, the advice is clear: don't. A UV dose that's high enough to induce a tan is already much higher than the dose needed for vitamin D production. A four-year-long study of 1,113 people in Nambour, Queensland, found no difference in vitamin D levels between sunscreen users and sunscreen avoiders. Further reading: Is Sunscreen the New Margarine?
From what I can tell, about 15,600 Americans die from skin cancer each year. That puts it at a little less than half your risk of dying in a car accident. So rather than turning vampire and avoiding sunlight as much as you can, just employ safe practices. Just like you buckle your seat belt when riding in a car, use sunscreen when going outdoors. Or put another way, if you're going to freak out about this and avoid going into sunlight, you should be doubly-freaked out about riding in a car.
The incidence of historical melanoma should be considered. Highly considered. As humans, historically we spent a very large amount of time working outdoors in the sunlight. Yet when we do so today, we get cancer? Wait, then what has changed? Why would evolution deselect a protective measure like this? Is it evolution or is it something else?
Diet? Pollutants? Stress? Alternative radiation exposure (radio transmissions, microwaves, CRTs)?
What is the reason, not the result, what is the cause, not the symptom. We cannot simply avoid sunlight for the rest of our lives, we need it. In the words of idiots: nerd harder, science guys!
Is how we survived the 10's of thousands of years as hunter/gatherers without skin cancer eradicating us.
Sorry, teleporters just kill you and then make a copy. A perfect, soul-less copy.
I agree this is the right way to be thinking about this. You need to look at the evolutionary background of homo sapiens and consider that whenever you are evaluating what is healthy and what is not.
The problem I see is that it is a system with many complex inputs. Controlled experiments are impossible in most cases. But you can tease out usable conclusions nonetheless.
In the case of sunlight/UV it is pretty clear you need it within some range. Both zero exposure and high exposure (say naked in Death Valley in July with no shade) can be pretty easily be shown to be unhealthy.
But the real problem are variables that are often totally ignored in reports like this. Is the body's Vitamin A store/supply important? What about K2? What about many other micro nutrients or for that matter the condition of the immune system that suppresses cancer cells being generated all the time in the body?
There is a big difference (besides genetics) between a bushman who eats wild game to survive (including most of the animal) and other high-nutrient sources and the surfer dude that scarfs down fast-food burgers and fries and HFCS sodas before heading to the beach.
So when I read something like "THE ADVICE IS CLEAR: DON'T" without considering what a thousand generations of humans survived and flourished on what I actually see is an "authority" with very incomplete view of things and whose advice on anything but the obvious can be disregarded.
Yes, but tan as an attractive trait is relatively new, really only coming to be in the mid 1900's.
In most of the world, lighter skin is more fashionable. Go shopping in Asia or Latin America, and you will see shelves full of skin lightening products.
Even in America, tanning is done more for fashion than beauty. The point of fashion is not to attract a mate, but to signal status. A woman carries an LV handbag to raise her status among other women, not because men find it attractive. If anything, a man will think that she is either self absorbed and high maintenance, or that she already has a rich husband/boyfriend. Likewise, when men describe what they find attractive in a woman, "a good tan" is generally not mentioned.
"So Lindqvist decided to look at overall mortality rates, and the results were shocking. Over the 20 years of the study, sun avoiders were twice as likely to die as sun worshippers.
There are not many daily lifestyle choices that double your risk of dying. In a 2016 study published in the Journal of Internal Medicine, Lindqvist’s team put it in perspective: “Avoidance of sun exposure is a risk factor of a similar magnitude as smoking, in terms of life expectancy.”"
And also:
"Melanoma, the deadly type of skin cancer, is much rarer, accounting for only 1 to 3 percent of new skin cancers. And perplexingly, outdoor workers have half the melanoma rate of indoor workers. Tanned people have lower rates in general. “The risk factor for melanoma appears to be intermittent sunshine and sunburn, especially when you’re young,” says Weller. “But there’s evidence that long-term sun exposure associates with less melanoma.”"
So regardless of whether you believe sun is bad for your or not, I rather think saying "the advice is clear" is so abjectly wrong, you should probably take everything else that's said with a huge grain of salt. There is almost never completely clear advice when it comes to things like thins.