My (I believe) great-grandfather was on the Yale football team during their famed flying wedge days and back when the leather helmets were their only protection

My (I believe) great-grandfather was on the Yale football team during their famed flying wedge days and back when the leather helmets were their only protection. As far as my memory of our family records can remember, he died in his early fifties / late forties of some brain related complications I can't recall at the moment. What I remember very well, however, is that the doctors of the day attributed the complications that caused his death to his time playing football on the Yale football team. I have no idea if the same conclusions would be drawn by doctors today today, but I thought it is an interesting anecdote to share nonetheless.