Heading Soccer Balls Can Induce Subtle Brain Changes Without Concussion or Symptoms

Recent research conducted by the University of Sydney reveals that heading a soccer ball can cause subtle alterations in brain structure and chemistry, even in the absence of any immediate symptoms or cognitive impairment. This groundbreaking study, published in the journal Sports Medicine—Open, is the first randomized controlled trial to utilize Magnetic Resonance Imaging (MRI) to assess the effects of heading on soccer players.

The study involved 15 male adult soccer players who performed heading drills where each player headed a ball 20 times in rapid succession, with the ball launched at a consistent speed from a machine. Their brain, blood, and cognitive functions were then evaluated immediately afterward, with comparisons made to a control condition involving kicking instead of heading. MRI scans detected minor but measurable changes, including altered brain chemistry in motor-control areas and decreased electrical conductivity across white matter regions. Blood tests revealed elevated levels of GFAP and NFL proteins—biomarkers associated with brain injury and dementia risk—although these levels remained within lower ranges observed in other brain conditions.

Importantly, the participants did not show any loss of cognitive function following heading, suggesting that the effects are microstructural and subclinical. The findings imply that even routine, symptom-free heading in soccer may lead to micro-level disruptions within the brain, raising concerns about the long-term implications of repetitive impacts.

Dr. Nathan Delang, lead researcher, emphasized that while the study does not prove causation of dementia, the elevation of these biomarkers indicates subtle cellular disturbances. Ongoing research aims to determine whether such changes accumulate over time and what impact they may have on long-term brain health.

Several countries such as the United States and the United Kingdom are considering or have implemented restrictions on heading, especially for young players. Australia has not yet adopted a formal ban but is actively discussing safety measures. Researchers like Dr. Danielle McCartney advocate for cautious approaches and further studies to understand the potential cumulative effects of heading, with a focus on protective interventions such as nutrition and cannabinoids.

Ultimately, this research underscores the need for continued investigation into how repeated head impacts influence brain health, even without overt symptoms. It calls for sports organizations and players to consider the risks of frequent heading and to explore safer practices to preserve cognitive well-being in athletes.