Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Time to sunburn

deepnote.com

Post reply on HN
Print view View original

81–90 of 121 posts

Re: Time to sunburn

#81

Post by gojomo »

wahern wrote: post #74
gojomo wrote: post #59

Earlier quoted context omitted.

But, after 50+ years of rising sunscreen use, there's essentially no data showing more sunscreen use reduces skin cancer. Sunscreen definitely prevents sunburns, and almost certainly delays visible skin aging/weathering. Those may be enough benefits for some people. But the people/populations using more sunscreen are also having more skin cancer. Some theories compatible with these observations are: • While preventin…

> But, after 50+ years of rising sunscreen use, there's essentially no data showing more sunscreen use reduces skin cancer. 50% reduction in melanoma: https://pubmed.ncbi.nlm.nih.gov/21135266/ 40% reduction in squamous cell carcinoma: https://pubmed.ncbi.nlm.nih.gov/10475183/ See, generally, https://www.skincancer.org/skin-cancer-information/skin-canc... Perhaps you were thinking of basal cell carcinoma, the most com…

Melanomas are the skin cancer of primary concern.

Your "50% reduction in melanoma" link is interesting, but pretty small & low-powered - and followup comments (such as https://ascopubs.org/doi/10.1200/JCO.2011.35.5727) highlight potential major problems in study design. For example:

• Study wasn't originally designed to detect effect on melanomas - that endpoint was added later. (This, alone, suggests possible p-hacking.)

• Instructions thus didn't even direct sunscreen application to the areas melanomas most often occur. Yet, at followup both control & intervention groups had a disproportionate number of melanomas in exactly the areas where application had been directed (and most applied, by self-reports, in both groups). As the commenters note, this is actually consistent with the theory that sunscreen encourages overexposure moreso than it protects.

• Small changes in arbitrary study choices - like to what extent back/leg melanomas were considered (when those areas weren't part of the encouraged sunscreen-application area), or whether a 1, 2, or 4 year exclusion of early events applied – remove the claim of 'significance', suggesting a very fragile result.

If the protective relationship of sunscreen were real, it'd have lots of studies with robust results. Or, the massive increases in recent decades in SPF factors, sunscreen purchasing/use, and sun-avoidance messaging and practice would've reduced melanoma rates. Instead, melanoma rates keep going up. To me, that's far more powerful evidence than a repurposed study with 11 more melanomas (but fewer invasive ones!) in a slightly-less-sunscreen-using control group.

The squamous study is also murky, though not as much. Its abstract notes, "There were no significant differences in the incidence of first new skin cancers between groups randomly assigned daily sunscreen and no daily sunscreen (basal-cell carcinoma 2588 vs 2509 per 100,000; rate ratio 1.03 [95% CI 0.73-1.46]; squamous-cell carcinoma 876 vs 996 per 100,000; rate ratio 0.88 [0.50-1.56])." The same number of people got new skin cancers in both groups! It's only the secondary count of tumours where the control group had more. I'm unsure that's an important protective effect.

But going back, I really should have said: "no data showing more sunscreen reduces deadly skin cancers". There's a reasonable amount of evidence sunscreen reduces various kinds of mild skin-tumours, much like the obvious-to-the-naked-eye effectiveness against sunburns.

But for melanomas/death-by-skin-cancer – the top worry of most sunscreen users – any effect is either very weak, non-existent, or possibly even inverse.

Re: Time to sunburn

#82

Post by mywittyname »

I think you're API key might be out of requests. I'm getting this error, no matter what location I put in, even though the Location block correctly returns the coordinates for whatever city I put in.

    Exception                                 
    Traceback (most recent call last)
     in 
          7 location_response = requests.get(f'https://api.opencagedata.com/geocode/v1/json?key={OPENCAGEDATA_API_KEY}&q={Location}&no_annotations=1&limit=1')
          8 if not location_response.ok:
    ----> 9     raise Exception('Location not found')
         10 
         11 location_json = location_response.json()

    Exception: Location not found

Re: Time to sunburn

#83

Post by hawski »

simonsarris wrote: post #31
jeremyw wrote: post #21

Consider removing omega-6 seed oils from your diet. Like many others who have tried it, I now have a normal tan response, where in the past I burned in a heartbeat. Note: you do need to wait a few months for the fatty acid composition of your skin to turn over.

Same: I suspect a good omega 3 ratio greatly reduces skin damage with sun. Anecdotally it's worked for me and my wife when we started eating a lot more eggs/red meat and less O-6 products. We haven't used sunscreen in a few years now because of it. There are some studies that suggest this is true, such as: https://pubmed.ncbi.nlm.nih.gov/7561154/ (note: N = 13) And Oregon State "Essential Fatty Acids and Skin Health"…

But aren't eggs themselves overall much more an O-6 source than O-3?

Re: Time to sunburn

#84

Post by mrfusion »

hprotagonist wrote: post #33

I _hate_ sunscreen. It's unpleasant to wear. I always do, but it's not my favorite part of summer by far. This year i am experimenting with rashguards and big stupid floppy hats.

I got a water based one which doesn’t feel bad but then I’m not sure if it stays in when I sweat.

Re: Time to sunburn

#85

Post by ReptileMan »

qmmmur wrote: post #27
version_five wrote: post #7

Earlier quoted context omitted.

That was the first thing I wondered too. My skin is Type I or lighter going by the chart. But my neck and arms and face are much darker from a life spend outside. It says I can only go outside for seven minutes without sunscreen, which i believe if i was at the beach, but I know I can go outside much longer than that in a t-shirt without any burn.

You are repeatedly damaging your skin which is why it's darker.

You are repeatedly damaging your muscles and tendons in the gym which is why they become bigger, stronger and denser. So where does that leave us?

Re: Time to sunburn

#86

Post by ReptileMan »

hprotagonist wrote: post #33

I _hate_ sunscreen. It's unpleasant to wear. I always do, but it's not my favorite part of summer by far. This year i am experimenting with rashguards and big stupid floppy hats.

Unless you are a field worker, fisherman, truck driver or some other similar professions, I think you can ignore the sunscreen. You are very rarely forced to be exposed to the harshest sun for prolonged periods of time.

Re: Time to sunburn

#88

Post by JadeNB »

A minor suggestion: the image for the Fitzpatrick skin type labels them "Type 1", "Type 2", etc., but the selector labels them "Type I", "Type II", etc.
Post reply on HN