A study of nearly 20,000 National Football League players has found they are four times more likely than the general population to die of neurodegenerative diseases, including ALS, dementia, and Parkinson’s disease.
The study, led by researchers at Boston University, Mass General Brigham, and the Concussion & CTE Foundation, is the largest of its kind to date of mortality in pro football players.
Although National Football League (NFL) players had lower chances of death from cancer and cardiovascular disease, which was attributed in part to their physical fitness, the researchers say this only highlights the athletes’ heightened risk of neurodegenerative disease.
Given their physical health, NFL players could be expected to also have better protection against diseases like dementia—but it appears that’s not the case.
Previous BU research has shown a high rate of chronic traumatic encephalopathy (CTE)—a neurodegenerative disease caused by repeated hits to the head that’s been tied to a range of symptoms—among deceased former NFL players whose brains were donated for research.
Related: Marigolds emerging as new plant-based protein source
The researchers found NFL players’ mortality rates for dementia were 3.8 times higher and 3.88 times higher for Parkinson’s.
Jesse Mez, a senior coauthor on the latest study and BU CTE Center codirector of clinical research, says a fourfold increase in dementia rates from a presumed environmental cause is immense—and brain bank studies indicate that CTE is the primary explanation.
The study included all current and former NFL players—19,824 athletes—who played at least one professional game and made their debut between 1960 and 2019.
Among the deceased NFL players, 178 had died of neurodegenerative disease, 106 of dementia, 39 from Parkinson’s disease, and 33 of amyotrophic lateral sclerosis (ALS).
They found those who died of neurodegenerative disease were older and had longer careers, starting and playing in more games.
Players who stayed in the NFL for more than five years had double the risk of dying of neurodegenerative disease than those who bounced out after just one to four seasons.
Related: New 3-in-1 Vaccine Protects Against Flu COVID RSV
Non-speed players—offensive and defensive linemen—had lower neurodegenerative and dementia mortality rates than those who took to the field in all other, or speed, positions.
NFL players in speed positions had twice the dementia rate of non-speed players, potentially related to greater cumulative g-force exposure, which has been associated with higher neurodegenerative disease risk.
Despite the grim rates of neurodegenerative disease death, the researchers did discover that NFL players had noticeably lower overall mortality than the general population.
Former and current pro players were less likely to die of cancer, cardiovascular disease, and a range of other causes.
They published the results of this study in eClinicalMedicine, an open access journal from The Lancet.