This ingredient is an antioxidant which means it can remove free radicals from our body, something that can cause cancer. It is in fact naturally occurring in humans, to support the breakdown of fats cell. We can also obtain this from food such as wheat, avocado and dairy products.
It is found in sunscreen because of its ability to fight free radicals. It tends to be found in sunscreen for that reason, we get lots of free radicals from the sun!