“It’s concerning because it was such a change,” said Dr. Ann McKee of Boston University, the study’s lead researcher.
“Childrens’ brains are rapidly developing between eight and 12 years old. They’re laying down new networks, they’re pruning the different connections. They’re sort of enhancing their brain,” McKee said.
The study also showed that for each year earlier kids begin playing football, their symptoms will progressively show up about two and a half years sooner.