And we have so much ethnic diversity in the US, that we must always make a recommendation (to those most at risk) that applies across the board. I’m not white. I don’t know how long it would take me to burn. I’m not dumb enough to have conducted that experiment, but I do know that I’ve been out in the Florida sun from 12pm to 2pm in August with no sunscreen on and haven’t burnt. I had just the slightest pinkening of the skin once in my life on my shoulders. But, as a woman, I’m told night and day that I must always wear a moisturizer (which I don’t think I need because my skin is not dry) with *at least* SPF 15. SPF is a multiplication factor. If you burn in 15 minutes, you can wear SPF 15 and be out in the sun for 225 minutes. So, someone like me should never need it, I say. Who needs all those chemicals?!
Given our genetic diversity, there is always a commonsense aspect to medical advice. Advice good for one group may be unnecessary for another.