In Copenhagen in 1932, at the Second International Congress of Light—which sounds like some sort of Illuminati gathering—a bunch of physicists got drunk and created arbitrary divisions within ultraviolet light. You’ve almost certainly seen these arbitrary divisions before: they’re called UVA and UVB, and maybe your dermatologist explained them to you roughly like this:This is not exactly true, but a perfectly fine simplification for our purposes.
The FDA allows any sunscreen that has an SPF of 15 or higher that also passes its broad-spectrum test to say that it “decreases the risk of skin cancer . . . caused by the sun.” What’s the evidence for that claim?It’s kind of embarrassing to admit this, but so far there appears to have been onlyrandomized controlled trial that tested whether sunscreen could reduce the risk of skin cancer, and that trial was mostly focused on non-melanoma skin cancers.
What about melanoma? Again, the evidence here is . . . less than ideal. The only randomized controlled trial on melanoma in adults was actually a continuation of the trial we just talked about. Both this trial and a couple of cohort studies suggest that sunscreen does have a protective effect. Data on melanoma rates reveals a bit of a paradox: even though lots of white people throughout the world use sunscreen, melanoma rates have not gone down or even stayed flat. In fact, over the past thirty years,One explanation could be that people enjoy tanning and burning the living crap out of themselves more than they used to, so even though they use sunscreen, they also expose themselves tomore sun than they used to.
But there’s another hypothesis. It was advanced by a Belgian epidemiologist named Philippe Autier, and although it’s supported by two randomized controlled trials he’s helped conduct, it remains controversial. Autier believes that sunscreen use among white people who like to sunbathe actuallytotal UV exposure, which could lead to melanoma. His thinking goes like this: White people like to intentionally expose themselves to the sun to get a tan, but they don’t like to burn.
Health Health Latest News, Health Health Headlines
Similar News:You can also read news stories similar to this one that we have collected from other news sources.
Source: TheStarPhoenix - 🏆 253. / 63 Read more »