A new study published by the National Institute for Occupational Safety and Health (NIOSH) found that National Football League (NFL) players may be at a higher risk of death associated with Alzheimer’s and other impairments of the brain and nervous system than the general U.S. population. These results are consistent with recent studies by other research institutions that suggest an increased risk of neurodegenerative disease among football players.

Neurodegenerative Causes of Death among Retired National Football League Players,” examined 3,439 NFL players who played at least five seasons between 1959-1988. The study relied on death certificate information for causes of death and at the time of analysis, only 10 percent of the participants had died. Of the 334 players who had died, Alzheimer’s, ALS and Parkinson’s Disease were listed for 17 of them.

“Multiple research studies have raised concerns about the longer-term health effects of recurring concussions,” said NIOSH Director John Howard, M.D. “Our analysis of NFL players’ mortality from neurodegenerative disorders may give insight into some of these questions.”

Athletes, including professional football players, generally have a better than average overall health status than the general U.S. population. However, death involving neurodegenerative causes among the retired players was three times higher than in the general U.S. population, and the risk for two major subcategories, Alzheimer’s and ALS, were four times higher. Of the 334 deceased former players, neurodegenerative causes were reported 17 times; it would be expected that in a group this size from the general population, neurodegenerative causes would have been reported only 5.2 times.

While the research findings do not establish a direct cause-effect relationship between football-related concussions and death from these neurodegenerative disorders, the findings do support current research that professional football players are at increased risk of death from these particular disorders.

“Although the study has its limitations,” said Everett Lehman, M.S., lead author “the research is significant in that it takes a look at a current issue that is of great concern to the professional football community surrounding brain disease and mortality.”

Other research suggests that chronic traumatic encephalopathy (CTE), a neurological disease that can occur years after exposure to repetitive concussive injuries and exhibits symptoms similar to Alzheimer’s disease and ALS in some individuals, has been identified in players who have sustained football-related concussions. The study points out that since CTE is a newly defined diagnosis, it is possible that some deaths attributed to Alzheimer’s disease or ALS on death certificates may actually have been related to CTE, though authors were not able to directly assess this in their study.