According to a new study from the Boston University CTE Center, every year someone plays tackle football, their risk of developing chronic traumatic encephalopathy (CTE) rises by 30%. Additionally, for every 2.6 years of play, the risk of developing CTE doubles, as bu.edu reports.
The researchers studied 266 deceased former amateur and professional football players, and unlike previous studies, included dozens of brains of former football players who had not suffered CTE, allowing a basis for comparison.
The Daily Mail explained, “CTE sufferers have clumps of tau protein built up in the frontal lobe, which controls emotional expression and judgment (similar to dementia.) This interrupts normal functioning and blood flow in the brain, disrupting and killing nerve cells. By stage 3 … the tau deposits expand from the frontal lobe (at the top) to the temporal lobe (on the sides). This affects the amygdala and the hippocampus, which controls emotion and memory … Symptoms of the degenerative disease don’t typically become evident until years after the head traumas were sustained.”
Lead author Jesse Mez, director of BU’s Alzheimer’s Disease Center Clinical Core, stated, “While we don’t yet know the absolute risk of developing CTE among American football players, we now can quantify that each year of play increases the odds of developing CTE by 30 percent. We hope that these findings will guide players, family members, and physicians in making informed decisions regarding play.”
The study’s corresponding author, Ann McKee, director of the BU CTE Center and chief of neuropathology at VA Boston Healthcare System, added, “This study is a testament to the hundreds of families who have donated their loved one’s brain…. It is only because of this support that we can confidently estimate the strength of the relationship between duration of [football] play and risk of CTE.”
The researchers included other variables in their study, as bu.edu reports, including, “total number of concussions, football positions played, a person’s age at first exposure to tackle football, their participation in other contact sports, their race, and the presence of other diseases.” Bu.edu added, “They found no associations between these other variables and CTE risk or severity,” but noted that players with a CTE diagnosis had their odds double of getting CTE for every additional 5.3 years of football they played. Bu.edu explained, “Those who played tackle football fewer than 4.5 years were 10 times less likely to develop CTE than those who played longer, although several men who played four years or fewer were diagnosed with CTE, including three whose only contact sport was football. Those who sustained the longest careers, playing more than 14.5 years, were 10 times more likely to develop CTE than those who played fewer years.”
A 2017 study of American football brain injuries diagnosed CTE in 99% of post-mortem exams of former NFL players’ brains. The study’s findings stated, “CTE was neuropathologically diagnosed in 177 players across all levels of play (87%), including 110 of 111 former National Football League players (99%).” Additionally, “The median age at death for participants with mild CTE pathology (stages I and II) was 44 years (IQR, 29-64 years) and for participants with severe CTE pathology (stages III and IV) was 71 years (IQR, 64-79 years). The most common cause of death for participants with mild CTE pathology was suicide (12 [27%]) and for those with severe CTE pathology was neurodegenerative.”
Players in the NFL have an average career of 3.3 years.