The Truth Behind Sunscreen and SPF
How do you balance the benefits of being outside with the negative consequences?
The answer is simple: be outside as much as possible and limit skin damage from the sun. It’s not difficult: wear a hat and use some sunscreen. Make sure the sunscreen is broad spectrum, it will say it on the label. An SPF 15 used right blocks 93% of the skin burning rays. An SPF 30 blocks around 97%. An SPF 40 stops 97.5 and going to a 50 adds just 0.5% more. The message here is that an SPF 15 used correctly is really good enough for most people for daily care. If you're surfing, go higher but realize that using it correctly is a lot more important than some crazy SPF number.
People will try to make this complicated. Sunscreens make you vitamin D deficient. Just dumb and not supported by real world evidence. What makes you vitamin D deficient is a poor diet and not getting outside. Sunscreens are endocrine disruptors. Another piece of misinformation. Under extreme levels, in test tubes, sunscreens have an effect, but the levels required are 1000’s of times higher than ever happen in the real world. The one exception is benzophenone where the difference between the test tube stuff and actual use is only 100 times. So, no reason to use benzophenone and guess what, almost no sunscreen brand does at this point.
You have also probably heard that soy can be an endocrine disruptor. Same deal, soy naturally contains small amounts of chemicals called phytoestrogens so in theory, they are endocrine disruptors. By the way, nuts, seeds, broccoli, lots of grains, apples and many other really healthy foods contain phytoestrogens. The basic problem with all this sort of nonsense is that people take a laboratory finding and try to apply it to the real world when it makes no sense. It’s a goofy example, but take cells like the ones they use in these experiments and put them in pure water and they burst. Conclusions: water is lethal, never ever go swimming or you will explode. This is not to say such experiments, properly understood, can have real meaning, but they need to be understood. Instead, what happens is these bits of information are taken out of context as clickbait and well meaning readers become obsessed and anxious as do all the other people in whatever social media bubble they exist in. Eventually, completely irrelevant things become “true” and people get hurt.
So, bottom line, you wanna be healthier for longer, don’t be stupid. And you don’t need other people telling you what is stupid, you pretty much know it. Drinking so much your brain literally does not work can't be good. Driving when you’re really tired is not smart and getting so much sun, your skin turns red and hurts is clearly a bad idea.