The NFL would like everyone to just calm down about all the brain-melting that they help create every Sunday, at least until they can finish their own personal scientific study that will be totally fair and not at all biased.
The league's "committee on concussions"—the fact that you even have to form a committee on concussions should tell you something—is currently conducting a long-term study on the effects of head injuries on NFL players, and even though it won't be finished for several more years, some experts in the field are already calling it a load of bunk. Not only is the science itself dubious, but the man conducting the research is not exactly an impartial juror. The New York Times tears it down in today's paper:
Every independent expert in epidemiology and neurology contacted by The New York Times cited at least one of the following issues: that the study's paucity of subjects will leave it unable to find any statistically significant difference in dementia rates; that a study financed by the N.F.L. and run by its committee doctors cannot be considered trustworthy; and that Dr. Ira Casson, the league's primary voice in discrediting all outside evidence, should not personally be conducting all of the neurological examinations.
Casson is already on record as saying there is no evidence of a connection between the brain trauma experienced by NFL players and long-term health problems. Yet, he is the one doing the neurological examinations on former players that will make up the bulk of the study. It's easy to see why he might want the results to turn out a certain way. In fact, half the doctors working on the study are employed by the NFL. (Casson's response to his critics is essentially, "Hey, who's the doctor here?")
In addition, the study is only comparing NFL players to other (non-professional) football players, instead of comparing them to the general population, which means it will be harder to detect differences between the two groups. Finally, the NFL is gathering test subjects by sending letters and phone calls to former players who, as one neurologist helpfully points out, are highly unlikely to respond if their brains have already turned to mush.
I guess we'll never really know whether getting repeatedly hit in the head with blunt objects is bad for your health. Oh well.