Its like everyone's arguing we should optimally live in darkness. As if 1. Humans didnt evolve living outdoors, 2. Everyone ages at the same rate 3. If they did, no one would ever get MM again. Like many things across the universe, too much of a good thing becomes bad. And "too much" varies considerably from one individual to the next. And no one in their 80s who avoided exposure to the sun is without wrinkles.