[49531]

> • Known carcinogens commonly used in sunscreens, or present as contaminants, are actually causing increased rates of skin cancer.

I am curious to see a citation for this claim.

> Generally, large population studies show positive effects of moderate sun exposure on many health outcomes, including overall longevity, heart disease, and non-skin cancers. Meanwhile, Vitamin D supplementation studies have usually not found that such supplementation alone reverses the correlations of many diseases with low Vitamin D. Thus, Vitamin D may not be the only mechanism by which sun's benefits are achieved.

I am also curious to see these studies, and wonder if they control for other variables like physical activity.

I think it's an incorrect framework to say that you have to choose between skin cancer and heart disease, you can avoid both through different lifestyle choices.

[baumandm]

Here's a recent HN discussion of a study that found benzene in 27% of tested sunscreen samples: https://news.ycombinator.com/item?id=27292387

[gojomo]

Many intentional functional ingredients in sunscreens are known carcinogens and absorbed at levels beyond any safety testing:

https://www.webmd.com/skin-problems-and-treatments/news/2020...

Contamination of sunscreens with common dangerous byproducts of industrial processes like benzene is common:

https://www.washingtonpost.com/lifestyle/wellness/benzene-su...

By comparison, shade contains no carcinogens.

Sun exposure correlated with longer life (even while also being correlated with more cancer deaths!):

https://www.health.harvard.edu/blog/heres-something-unexpect...

An earlier broad survey also finding natural sun exposure decreasing all-cause mortality (but not use of tanning beds, despite similar effects on Vitamin D production, again suggesting D-supplements alone don't replicate the sun):

https://cebp.aacrjournals.org/content/20/4/582

I'd agree, it is hard to disentangle these correlations with things like general levels of outdoor activity and socializing.

But even so: if people who are healthy for other reasons tend to spend more time outside in sun, maybe it'd be a good idea to join them, & perhaps absorb their other habits as well, rather than live in fear of the sun? (Maybe even the sun is damaging on many levels, but the other benefits of activities inherently done more under the sun offset those effects, even if just via mood/optimism?)

I'd say instead that it's an incorrect framework to embrace an illusion of total control "through different lifestyle choices" without tradeoffs. Every activity has a mix of risks and benefits. Certain vigorous activities with a higher risk of accidental death may deliver other fitness and social benefits. If an extra 5 hours of sun every week doubles melanoma death risk, but reduces cardio/cancer death risk just 1%, that sun would still be a net-mortality benefit.

Such tradeoffs are real & everywhere. Trying to engineer both benefits – "can I do everything other healthy people do usually do outdoors indoors? can I find the least-dangerous sunscreen? will vitamin D supplments, perhaps with a bunch of other diet changes, simulate the sun's benefits?" – also includes costs, in research time, psychological focus, neurotic behaviors, etc, for diminishing returns.