The authors concluded that incurring repeated head impacts in football between the ages of 10 and 12, a critical and sensitive window for brain development, may increase the risk of later-life cognitive impairment. During those early years, the brain is rapidly building connections between neurons.

“We have findings from former NFL players, so it can’t be generalizable to the rest of the football-playing public,” Stern said. “But it does suggest something that I think makes logical sense. The logic is you shouldn’t hurt your brain over and over and over again as a child.”

The top medical official for Pop Warner, the nation’s largest and oldest youth football organization, dismissed the study as “flawed.” Dr. Julian Bailes, chairman of its medical advisory committee and co-director of the Northshore Neurological Institute in Evanston, Illinois, told “Outside the Lines” that the sample is too small to draw any conclusions from, and that the results of NFL players cannot be compared to that of athletes who never made it to that level.

via ESPN