More studies coming out of the University of North Carolina Hospital are confirming what many already suspected: a career in the NFL can lead to long-term cognitive problems, probably caused by years of repeated concussions and other brain injuries while on the field. The Study of Retired Athletes at UNC has found that any athlete who suffers three or more concussions during their tenure on a professional team is five times more likely to suffer from cognitive problems as they age and three times more likely to suffer from permanent concussion.

NFL player Jimmie Giles was in the game for many years before retiring to run a financial business and enjoy the money and fame that came with being a successful professional athlete. But the man, 55, suffers from a variety of serious health problems, including arthritis, joint problems, and cognitive issues. Giles said that he had to shut down his business in 2007 because he couldn’t concentrate on his work and sometimes forgot where he was or what he was doing. Giles said he had at least a dozen concussions during his football career and that he would never had played at all had he known the long-term health consequences of the game.

All in all, 62 percent of all retired football players say that they felt mentally worse off than other people their age who were not professional athletes. And almost half say that they wouldn’t choose the same career path if they had known the mental and physical consequences of playing football long-term.