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Comment by atombender | Hacker News Reader

The idea of a "base tan" that is protective against sunburns and skin cancer has found to be a myth [1], unfortunately. It has no protective effect, and may be counterproductive, since it gives you more confidence to go out in the sun without sunscreen protection.

[1] https://www.scientificamerican.com/article/fact-or-fiction-a...

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Sun exposure may have a range of other beneficial effects:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5086738/

In the end, I think it's flatly obvious that too much or too little (as anyone who lives in northern latitudes can tell you) sun exposure is bad for you. There's an ideal range somewhere.

Sure. I was only addressing the suggestion that a "base tan" is protective.

The data in the article you linked doesn't agree with you - it says a base tan gives an SPF of 2, and gives the example that that means if you would normally burn in 10 minutes, it will now take 2x the time (20 minutes) to burn. Doubling the burn time is hardly "no protective effect".

While it is “something” regarding cancer risk, it’s way closer to nothing than to regard this as any kind of useful protection.

Bear in mind this was after only two weeks of exposure, on people with pale skin with simulated sun exposure trying to mimic a very northern latitude (London). They also only used UVA and UVB rays, omitting the infra-red spectrum.

The sensible advice is generally to spend a few months gradually increasing your unprotected sun exposure, then towards the end of the summer may be able to hang out unprotected in the morning/midday sun for an hour or two without burning. Of course everyone's mileage is going to vary here, as is their tolerance for risk vs reward of sun exposure.

Tan already means DNA damage, AKA increased cancer risk. Just because you won’t necessarily be burned, it doesn’t mean, it’s not bad for you. So it’s definitely not that simple.

Right, it's a trade-off. The benefits of vitamin D, infrared spectrum light on the immune system, and blue light on hormone signaling likely outweigh some increased skin cancer risk if you are smart about your exposure patterns.

There is some evidence than sun exposure decreases your risk for many other cancers moreso than it increases your risk of skin cancer, although exposure patterns and other factors are going to be very important here. And obviously there's a lot more than just cancer that a healthy body and immune system is protecting you from.

You need to be on the sun minimal time to maximise these benefits. It happens earlier than getting for example a tan.

citation needed

First of all, funny that this is the first comment for which you need citation. Second, a simple Google search can help you.

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