Even amateur athletes can suffer from a degenerative brain disease linked to repeated blows to the head, a study suggests.
Researchers at Boston University found that 63 of 156 brains of athletes under the age of 30 tested had chronic traumatic encephalopathy (CTE).
Of these, 45 — or 71 percent — came from amateur players competing at the youth, high school, or college level.
Players competed in sports such as American football, ice hockey and soccer, they said.
Scientists added that they had likely diagnosed the first US case of the condition in a female athlete, linking it to a 28-year-old collegiate soccer player who was not named. It comes after an Australian woman became the first female professional athlete to be diagnosed with the disease last month.
The scan above shows the brain of a healthy 27-year-old (left) and that of a person with CTE (right). These were presented by Dr. Ann McKee, a neurologist at Boston University, as she presented the results of a separate study
CTE is a serious disease caused by repetitive blows to the head – for example from a ball – that cause a buildup of tau proteins in the brain.
These are believed to interfere with communication between neurons, leading to memory problems – such as difficulty remembering recent events – and emotional problems – such as depression or anxiety.
About six percent of Americans are believed to have the disease, but the diagnosis cannot be made until a person dies and the brain tissue can be analyzed.
For the paper, scientists analyzed 156 brains stored in the university’s UNITE brain bank — the world’s largest tissue repository — all donated between 2008 and 2022.
They only looked at the brains of athletes under the age of 30 to prevent age-related degeneration from interfering with the results.
The fatalities were not related to CTE, in which athletes died by suicide – one of the most common causes of death under the age of 30 – or by drug overdose.
In the study, donors were between the ages of 17 and 29, with an average age of 22.
Most played American football – 60 percent of the total – while many also played football – 15 percent – and ice hockey – 10 percent. Several had played amateur wrestling, rugby and professional wrestling.
Overall, 40 percent of the athletes in the study were diagnosed with CTE after testing.
But the scientists cautioned that their sample was not nationally representative and that it was likely that actual CTE rates among players were much lower. Estimates suggest that six percent of all Americans have the condition, while many are completely unaware of it.
Of the 48 donors diagnosed with CTE who played football, 37 were amateur players, while 11 played for the National Football League (NFL).
The position they played in made no difference to their chances of being diagnosed, researchers found.
But those who played longer – or an extra 2.8 years – were at greater risk.
Eleven of the brains evaluated in the study were female, of which only one — a 28-year-old female athlete — showed signs of CTE.
Dr. Ann McKee, the neurologist who led the study, told CNN: “It is fairly well recognized that CTE is a risk for elite athletes, especially football players.
‘But it does show that CTE can start in very young athletes who only play amateur sports.’
She added: ‘This study clearly shows that the pathology of CTE starts early.
‘The fact that more than 40 percent of young contact and collision athletes in the brain bank have CTE is remarkable.’
The article was published in the magazine JAMA neurology.