I went on a tour of the Rawlings factory, as they supply helmets to a lot of college and high school teams. They're very, very concerned about the quality of their helmets but continue to emphasize there's no such thing as a concussion proof helmet. But they're also educating coaches and volunteers for youth footballs teams and sponsored a concussion app that helps coaches and non-medical personnel determine when a kid *might* have some concussion symptoms and thus, help trigger additional help. The evidence suggests that if a brain is allowed to heal, most of these long-term brain injuries can be avoided.
It's like a bruise. If you avoid hitting the soft tissue for a while, it heals. If you continue to hit it over and over again, it messes up that area. Now exchange muscle for brain matter, and you see the problems with repeated concussions.
There's also evidence that ALS (Lou Gehrig's disease) might have been caused by repeated brain trauma in Gehrig's case. Researchers pulled up game summaries of his playing time and found, over and over, that he did get "dinged" or knocked in the head numerous times. And, of course, he never took a day off to allow healing.
It's kinda sickening to think that the consecutive game streak that earned him fame and the nickname the Iron Man may have very well caused his death.