Northwestern University Jul 11 2025 In recent years, some scientists and advocates have warned that playing contact sports like football and hockey may increase the risk of brain diseases like Alzheimer's disease or chronic traumatic encephalopathy (CTE) due to a buildup of a specific protein in the brain. But a new Northwestern Medicine study of 174 donated brains, including some from former high school and college football players, pumps the brakes on that theory.  The long and short of it is