Nothing beats that thrilling moment when a soccer player rushes towards the ball, jumps high to head it, and sends it into the net, scoring a goal that ignites the enthusiasm of the fans in the stands.
However, behind this joyous scene lies a worrying scientific reality: repeatedly heading the ball can leave cumulative effects on the brain, which may appear after decades in the form of neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and motor neuron disease, according to the BBC.
About a century ago, medical circles began to realize the potential dangers that violent sports could cause to the brain.
## Brain diseases
In 1928, American pathologist Harrison Martland published a study in which he referred to what was known among boxers as “punch-drunk,” a condition characterized by staggering and mental confusion suffered by those who are subjected to repeated blows to the head.
Later, this condition was classified under the name “dementia pugilistica,” a disease associated with boxers who suffered repeated brain injuries.
Over time, it became clear that the problem was not limited to boxing. In 2002, English footballer Jeff Astle died at the age of 59 after suffering from early dementia, while American football star Mike Webster died at the age of 50 as a result of similar cognitive decline.
Examinations revealed that both players suffered from chronic traumatic encephalopathy (CTE), the modern diagnosis that replaced the term “dementia pugilistica.”
Other prominent cases have reinforced concerns, including the suicide of former Chicago Bears player David Duerson in 2011 after struggling with depression, where an analysis of his brain revealed that he also had chronic traumatic encephalopathy.
Consultant neurologist at the University of Glasgow, Willie Stewart, confirmed that this disease is “exclusively linked to a history of repeated head injuries,” noting that its hallmark is the abnormal deposition of “tau” protein in the brain.
## Risk of contact sports
At Boston University, Ann McKee and her colleagues analyzed the brains of 376 former NFL players in 2023 and found that more than 91% of them had chronic traumatic encephalopathy.
Although this percentage may reflect bias in the sample, it reveals the extent of the risk inherent in sports that rely on physical contact.
A large-scale study conducted by Stewart in 2019 on about 8,000 former Scottish football players also showed that these players are 5 times more likely to develop Alzheimer’s, 4 times more likely to develop motor neuron disease, and twice as likely to develop Parkinson’s disease compared to the general population.
The study explained that defenders are the most at risk, while the risk for goalkeepers does not differ much from the general population.
