Transcript for Football Players at Greater Risk of Alzheimer's
Now, with football season here, a troubling now report tonight, we've long heard about the link between football, alzheimer's, lou gehrig's disease. Here's chris cuomo. Reporter: It is a sport derived from warfare, that is all about violence. Espn sports science says these crushing blows can be the force equivalent of a sledge hammer blow to the head. One study found the average player takes 900 to 1,500 head shots a season. We all know what happens out here on the football field. The pass is thrown, the player makes the catch, there are a couple of quick moves and then an explosive collision that makes the crowd go wild. But what we're learning about what happens to these players once they leave this field may be even more shocking. Today's study finds football players suffer a higher risk of death from brain-related diseases. There is a possibility that they might be at risk for develops degeneration later in life. Reporter: The rate of death varied dramatically by player's position. Quarterbacks and running backs, who play at higher speeds, were three times more likely to die from a disease from damage to the brain than less dynamic players such as linemen. The nfl announced today it is donating $30 million to fund research into brain injuries and other medical issues. But for all the research, the most pressing questions for families sending kids out on the field this fall is one without an answer, how can players be protected from the violence that is central to the game they play? Chcuomo, abc news, new york.
This transcript has been automatically generated and may not be 100% accurate.