I have fond memories of family vacations at the beach... running around all day, and then checking out the "reverse swimsuit" in the bathroom mirror that evening. Burn, baby, burn. The following week as part of our grooming ritual my sister would pull impressive sheets of dead skin off my back. Groovy.
OK, so that probably wasn't the healthiest thing in the world. Many of us probably had similar experiences, and so the current conventional wisdom of applying sunscreen anytime we go outside seems to make sense. Sun exposure equals skin cancer, right? Well, it's not that simple.
There are many benefits of sun exposure. Vitamin D is the obvious one. Every cell in our body has a receptor for this hormone, and having optimal levels minimizes the risk of a whole host of health issues. Reducing sun exposure may lower the risk of melanoma, but it simultaneously raises the risk of many other forms of cancer that are much more common. Sun exposure increases nitric oxide production which relaxes blood vessels lowering blood pressure and improving immune function. And check this out - the mitochondria in our cells are sensitive to the infrared spectrum and use this light to enhance energy production. We're similar to plants in that way.
Now, take a look at the ingredient list of sunscreen, and consider the chemical shit-storm you are applying to your skin. Your skin is an organ... and a very important one. It keeps all the nasty environmental stuff away from your internals. Would you rub that lotion on your liver, heart, or lungs?
For the hour-a-day (or less) that most of us spend outside we are better served by not using sunscreen. Of course, for long days at the beach it's better to use sunscreen than burn, baby, burn, but choose one from EWG's list to minimize the toxic load. Or better yet, if you're old like me just cover up with a hat and shirt. You won't be Instagram worthy, but the ride home will be a lot more comfortable, and your skin will thank you.