The NFL continues to research the impact of concussions on brain injury, but the researchers have ties to the NFL which raises questions about the validity of the data.
"For nearly two decades, the NFL ran a series of scientific experiments. The league formed its own research arm and published 16 papers about football and head injuries. The central conclusion -- that NFL players don't get brain damage -- led to public criticism, Congressional hearings and, in 2009, the abandonment of the project.
"But the NFL hasn't abandoned the science of concussions. Over the past three and a half years, the league has transformed itself into one of the largest funders of brain research in the United States, allowing it to maintain a powerful role in science that could affect millions of people and, not incidentally, the bottom line of America's richest and most popular sport."--Steve Fainaru and Mark Fainaru-Wada, ESPN