Is brain damage an inevitable consequence of American football, an avoidable risk of it, or neither? An editorial published yesterday in the medical journal BMJ poses those provocative questions. Chad Asplund, director of sports medicine at Georgia Regents University, and Thomas Best, professor and chair of sports medicine at Ohio State University, offer an overview of the unresolved connection between playing football and chronic traumatic encephalopathy, a type of gradually worsening brain damage caused by repeated mild brain injuries or concussions. The big question is whether playing football causes chronic traumatic encephalopathy or whether some people who play football already at higher risk for developing it. The Football Players Health Study at Harvard University hopes to provide a solid answer to that and other health issues that affect professional football players.