which health problem did he suffer from?
dementia
John Mackey (American football)
Several years after retiring from the NFL, Mackey began to suffer from symptoms of dementia. 
what is achelousaurus? It is a genus of centrosaurine ceratopsid dinosaur. describe its social behavior? They were herding animals, due to the large number of known bone beds containing multiple members of the same ceratopsian species. where did it get its name? It is named after a Greek mythological figure. who named it? Scott D. Sampson who is he? He is a Canadian paleontologist and science communicator. did he join any institute or university? Yes, at the New York College of Osteopathic Medicine on Long Island. mention a few of his works? He hosted "Dinosaur Planet", and published a book. where was he born? Vancouver, British Columbia. name a few famous sportspeople from the aforementioned island? Jim Brown, Julius Erving, John Mackey, Whitey Ford, Nick Drahos, and Carl Yastrzemski. what sports did the third person played? football did the third person have any highest authority in any association? He was the first president of the National Football League Players Association.
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John Mackey (American football) [SEP] Post-career health problems
Several years after retiring from the NFL, Mackey began to suffer from symptoms of dementia. In one notorious incident at an airport checkpoint, Mackey refused to remove his Super Bowl and Hall of Fame rings at the metal detector. When a guard insisted he take them off, Mackey bolted through the checkpoint. It took four guards to subdue him. “I'm just so thankful they didn't shoot him because they had no idea about his mental condition,'' His wife Sylvia said after the incident. “They easily could have mistaken him for being a bomb-toting terrorist.” His condition eventually worsened, and his family was forced to put him into a full-time assisted living facility.