BRAIN DAMAGE IN FOOTBALL PLAYERS is real say Scientists who are dissecting Dead Pro Football Players Brains.

http://www.motherjones.com/media/2014/10/80-percent-former-football-players-traumatic-brain-injury

Yesterday, the country's leading investigators of sports-related brain injuries released what could be their most shocking finding yet: Of the 79 deceased NFL players examined, 76 showed evidence of chronic traumatic encephalopathy, or CTE. The researchers at the Boston University CTE Center have examined, in total, the brains of 128 people who played football at all levels—from high school to the pros—and 101 showed evidence of CTE. The numbers buttress a growing body of evidence that suggests that playing football at any level can lead to grave health consequences.
In case you haven't been following the story, here's how CTE works: When the brain is subjected to repeated trauma—from the severe (and rare) concussion-causing hits to the repetitive, smaller impacts a lineman might absorb thousands of times in his career—its tissue starts to deteriorate. That causes the buildup of abnormal tau proteins, which interfere with a whole host of critical brain functions. In the short term, it can lead to memory loss and impaired judgment; in the long term, it can lead to severe depression and dementia. Ex-players describe its symptoms as crushing, and in many cases, the pain, unpredictable outbursts of rage, and memory loss becomes too much to bear.