The number of young people who play American football decreased from 2008 to 2016 according to the Aspen Institute, a research center. There are many reasons for this decrease. But some parents, such as businessman Mark Cuban, will not let their children play the sport because of concern about brain injuries. A recent study seems to support some of these concerns. It gives more evidence that too much American football is seriously damaging the brains of players. Scientists at the Brain Bank are studying a kind of brain injury known as Chronic Traumatic Encephalopathy. The Brain Bank is a center at Boston University in Massachusetts where brains and other tissue are stored and studied. Chronic Traumatic Encephalopathy, or CTE, is caused by collisions that push the brain around inside the skull. In a recent study, the scientists at the Brain Bank found high levels of CTE in dead football players.