Heading a soccer ball leads to brain damage, research shows

Researchers from the Radiological Society of North America (RSNA) analyzed the brain MRIs of 352 amateur soccer players, aged 18 to 53, both men and women. They discovered abnormalities in the white matter surrounding the brain, particularly in the frontal lobe, similar to CTE.

Chronic traumatic encephalopathy (CTE) is a progressive brain disease often associated with contact sports like boxing, MMA, or football, where athletes encounter repeated head trauma. People with early CTE can suffer memory issues, mood change, emotional instability, and behavioral problems like impulsivity or aggression. CTE has also been linked to depression and violence. The symptoms only get worse from there as the disease progresses: dementia, speech and vision issues, and Parkinson's-like symptoms with muscle motor control.

While taking hard knocks to the head isn't something you see normally in soccer, "headers" are.

The frontal lobe (forehead area) is the portion of the brain in which cognitive functions such as decision-making take place and memory resides. The forehead is what soccer players generally use for the most control when making a header shot or pass.

In the study, the 352 brain MRIs were compared to 77 non-collision athletes, such as runners, with a technique called diffusion MRI. dMRI focuses on the movement of water molecules within the tissues to detect subtle abnormalities like stroke, neurodegenerative diseases, and traumatic brain injuries (TBI) that are undetectable in traditional MRIs.

Most of the players in the study had never been diagnosed with TBI or concussion, highlighting the cumulative effect of sub-concussive impacts like headers.

Players more likely to head the ball showed abnormalities in the white matter adjacent to the sulci – the grooves in the outer layer of the brain, essential for maximizing the cortical surface area and to separate functional brain regions. White matter can be thought of as the communication highway for the central nervous system, transmitting signals to and from different parts of the brain and spinal cord.

"Our analysis showed that the white matter abnormalities represent a mechanism by which heading leads to worse cognitive performance," said Dr. Michael L. Lipton, professor of radiology at Columbia University Irving Medical Center in New York. Given the previous lack of serious head injuries to players, the study found a direct correlation between repetitive headers and poorer verbal learning performance, suggesting even seemingly benign impacts like a header can have a profound effect on the brain.

"...Repeated head impacts among healthy athletes [show] ... abnormalities occur in the locations most characteristic of CTE ... associated with a worsening ability to learn a cognitive task and could affect function in the future," said Dr. Lipton in an edited comment.

CTE – first described in 1949 by Dr. Macdonald Critchley and only solidified as a disease in the early 2000s by Dr. Bennet Omalu – has been disproportionately identified in athletes, particularly boxers and NFL players.

While there's not a lot to be done in boxing to mitigate head and "punch-drunk" brain trauma due to the nature of the pugilist, American football has long sought to reduce the risks. Players have been required to wear helmets since 1943, albeit leather-wrap helmets initially. By the 1950s, leather was traded for a more protective plastic helmet. Even with advancements in equipment, repeated head impacts have resulted in a wave of brain injuries among players.

A major hurdle in diagnosing CTE is that it can only be done postmortem, making research difficult.

NFL players like Aaron Hernandez, Frank Gifford and Junior Seau were diagnosed with CTE. Soccer players Jeff Astle and Scott Vermillion, hockey player Derek Boogaard, and WWE wrestler Chris Benoit were all diagnosed with CTE. All of which died in untimely and unfortunate circumstances, as is often linked with the symptoms of the disease.

In 2022, the National Football League (NFL) mandated the use of Guardian Caps – soft helmet covers that absorb and dissipate energy to reduce head injury – during preseason practice. And for the 2024 season, players are allowed to wear them during regular season games. Studies have shown the caps to reduce impact of collisions by 10% and 20% if both players in a collision are wearing them.

While the sight of bobblehead-looking Guardian Caps or Lionel Messi donning a helmet – not that there's been any suggestion of soccer adopting helmets – might be equally aesthetically off-putting, what price do you put on a healthy brain?

Source: Science Daily