Bubba Smith, the All-Pro defensive end in the N.F.L. who went on to a second career as a movie actor, had chronic traumatic encephalopathy, the degenerative brain disease linked to repeated head trauma, when he died in 2011.
The findings were confirmed by researchers affiliated with the Department of Veterans Affairs, Boston University and the Concussion Legacy Foundation, and released on Tuesday morning with the permission of the executor of Smith’s estate.
Smith is the 90th former N.F.L. player found to have had C.