People who start tackle football at a young age or play longer than 11 years may have less white matter in their brains, potentially leading to poor impulse control and thinking problems, researchers report.
The degenerative brain disease known as CTE, or chronic traumatic encephalopathy, has become a specter that haunts football.
“Just because you’re not diagnosed with CTE doesn’t mean there isn’t something structurally damaged in the brain.”
One-time stars — like the late NFL defensemen Irv Cross and Dave Duerson and Hall of Fame center Mike Webster — all once celebrated for their boasted exploits on the field, later found themselves doomed to far less glamorous retirements and stayed with them for years increasingly declining brain health, plagued by forgetfulness, dysfunctional thinking and poorly regulated emotions.
Now the new study is in brain communication suggests that the repeated blows to the head players suffer on the road to fame and glory may have a greater impact on their brain than previously known, regardless of whether someone has CTE or not.
“Just because you’re not diagnosed with CTE doesn’t mean there isn’t something structurally damaged in the brain,” says neuropathologist Thor D. Stein, associate professor of pathology and laboratory medicine at Boston University’s Chobanian & Avedisian School of Medicine.
“White matter damage may explain why soccer players are more likely to develop cognitive and behavioral problems later in life, even without CTE.”
Damage to the “wiring” of the brain
White matter is the brain’s wiring, made up of axons, or nerve fibers, that connect its billions of cells. It makes up about half of the human brain volume – without it our cells (the gray matter) could not communicate with each other.
“A lot of neuroscience and degenerative studies focus on the neurons or cells themselves, but more and more people are realizing that the connections can be damaged,” says Stein, director of the Neuropathology Core at the Alzheimer’s Disease Research Center and a resident neurologist at two Department of Health systems Veterans Affairs in the Boston area. “The cell itself may look okay, but its connection is not intact – and that’s what we wanted to look at in this study.”
To study the effects of repeated blows to the head on these connections, the researchers analyzed the brains of 205 amateur and professional soccer players. All had requested that their brains be donated to the BU-hosted UNITE Brain Bank, which contains more than 1,200 brains, upon their deaths. A majority of former players – 75.9% – were reported to be functionally impaired, and the researchers found that many (but not all) also had CTE.
“There is a cumulative risk – the more you play, the more your risk increases.”
For the study, Stein and his colleagues divided into two groups that worked blinded or independently. One group performed a pathological examination of the brain, examining samples through microscopes and dissecting white matter tissues to test for protein levels. The second group analyzed medical records and asked family members about symptoms.
Stein was part of the pathology team. He focused his efforts on studying myelin, a membrane of lipids and proteins that encases and strengthens the brain’s wiring—like the plastic wrap around an insulated wire. Using biochemical tests called immunoassays, he measured the levels of two myelin proteins, myelin-associated glycoprotein (MAG) and proteolipid protein 1 (PLP).
“How many of these proteins are present is an indicator of the integrity of the white matter,” says Stein. Less myelin, less efficient connections between brain cells.
The researchers targeted the frontal lobe, the part of the brain that controls many executive functions, from memory and attention to planning and self-control. It is also at the forefront of soccer hits and concussions.
They found that the more years someone played football, the less PLP they had; those who played longer than 11 years had lower PLP and MAG than those with shorter careers. They also discovered that donors who started playing tackle football earlier had lower PLP levels. Stein suspects that young, developing brains are particularly susceptible to damage from repeated soccer hits.
“Perhaps young people play at a young age, their connections could be particularly vulnerable to damage,” he says. “We found that if you started at a younger age, you tended to have fewer of these white matter-associated proteins decades later in life.”
The former players likely struggled to plan their days, control their emotions and understand the consequences of their actions while they were alive, Stein says.
“In our study, we found that in those over 50, lower white matter readings were associated with an impaired ability to perform normal activities of daily living, such as paying bills, shopping and cooking, as well as with more impulsive behavior. “
Great of Youth Tackle Football
The latest study should allow researchers to give families closure – by explaining what caused their loved ones’ dwindling brain health. The research could also provide a basis for helping future patients.
“These results suggest that existing tests that measure white matter injury throughout life, including imaging and blood tests, may help clarify possible causes of behavioral and cognition changes in ex-contact athletes,” says lead author Michael L. Alosco , an Associate Professor of Neurology at the Chobanian & Avedisian School of Medicine.
“We can also use these tests to better understand how repeated hits to the head in soccer and other sports lead to long-term white matter injuries.”
Stein hopes the work will also help people better assess the risks of playing soccer and other contact sports.
“There is a cumulative risk – the more you play, the more your risk increases,” says Stein, who supports the Concussion Legacy Foundation’s Flag Football Under 14 campaign. “One message we’re trying to get across is that you don’t have to be playing tackle football at a very young age – if you can shave just a little bit off those accumulated years of playing, you can have a really big impact on brain health.” This study is further proof of that.”
Funding for the study came from the National Institute on Aging, National Institute of Neurological Disorders and Stroke, NIA BU Alzheimer’s Disease Research Center, Department of Veterans Affairs, Veterans Health Administration, Nick and Lynn Buoniconti Foundation, and BU Clinical and translational science institute.
Source: Boston University