Coinciding with Super Bowl week, the journal Neurology just came out with a study by Boston University researchers that looked at retired professional football players, comparing the cognitive functioning of players who had started tackle football before age 12 with others who hadn't. Here is a summary of the findings, encapsulated in an accompanying editorial published in the same issue:

Forty-two former NFL players were studied, of whom half had been exposed to tackle football before age 12 and half had not. The mean age of the study participants was 52, and the total number of concussions was similar between the groups. Neuropsychological testing was conducted to measure executive function, memory and intelligence, domains commonly affected not only in mild traumatic brain injury but also in late-life dementia. Results indicated the players exposed to football before age 12 had greater impairment on all measures compared to the players who began to play football at age 12 or later.

The study was small and didn't do similar comparisons for former players whose football careers ended after high school. Still, a few other sentences from the editorial might give some parents pause about whether their kid should be going out for the team.

Football has the highest injury rate among team sports, and given that 70 percent of all football players in the United States are under the age of 14 and that every child 9-12 can be exposed to 240 head impacts during a single football season, a better understanding of neurobehavioral sequelae among children who play football is urgently needed.

Dunno. While waiting for those studies to be conducted, do you really want your kid taking 240 head bangs each fall (estimated upper bound is 585 hits)? Not just love taps either: "head impacts per season that parallel the magnitudes experienced by high school and collegiate football players." What about track and field?