Football Exposure Linked to Cognitive Decline & Inflammation in Players

Years of playing football may subtly alter cognitive function and emotional wellbeing later in life, with inflammation appearing to play a key role, according to two recently published studies. The findings underscore the need for ongoing research into the long-term neurological effects of repetitive head impacts, even those that don’t result in diagnosed concussions.

Cognitive Impacts Linked to Years on the Field

One analysis, published in JAMA Network Open, indicated that the duration of football play can adversely impact cognitive and neuropsychiatric function. Researchers evaluated data from nearly 4,000 former players, aged 40 and older, comparing their cognitive performance to a control group without a history of significant head trauma. The study assessed functions like memory, executive function, and depression levels.

Former players demonstrated poorer scores on several cognitive tests compared to the control group, including measures of memory and executive function. Notably, the number of years spent playing football was associated with increased difficulties in these areas. College-level players showed a greater risk of clinically significant cognitive and emotional issues compared to those who played only at the high school or youth level.

“These findings align with the idea that more repetitive head impacts over a long career can equate to greater risk of neurological impairment,” explains Robert Glatter, MD, an assistant professor at the Zucker School of Medicine at Hofstra/Northwell and emergency medicine physician at Lenox Hill Hospital, who was not involved in the study.

However, researchers caution that the study’s design, relying on self-reported data and a participant pool potentially biased towards those experiencing symptoms, limits broad generalizations. Further research is needed to account for factors like genetics, medical history, and socioeconomic status.

Inflammation as a Potential Pathway

A second study, published in Neurology, explored the biological mechanisms potentially linking football exposure to cognitive decline. Researchers investigated the role of inflammation and damage to white matter in the brain, specifically in the limbic region, which is crucial for memory. The research compared 170 former college or professional football players with a control group of individuals with no history of head trauma.

The study found that higher levels of inflammatory markers in the blood and cerebrospinal fluid were associated with structural changes in the limbic white matter. These changes, in turn, were linked to poorer memory performance among the former players. The association between inflammation and white matter damage appeared stronger in older participants.

Researchers suggest that inflammation may contribute to white matter damage by increasing fluid content within brain tissue and potentially disrupting the myelin sheath, which insulates nerve fibers. While the study doesn’t prove a direct causal link, it provides valuable insights into the potential biological pathways involved in long-term neurological consequences of repetitive head impacts.

“In this study, we see plausible biological processes – neuroimmune activation and axonal changes – mapped onto clinical complaints,” Glatter said. “If confirmed by further research, such findings could eventually lead to interventions that mitigate or even prevent long-term sequelae of RHI exposure.”

Understanding the Nuances of Risk

It’s essential to note that these studies do not suggest that all football players will inevitably experience cognitive decline. The findings highlight a potential increased risk, particularly with greater exposure to repetitive head impacts. The relationship between football and brain health is complex and likely influenced by a multitude of factors.

Melissa Shuman Paretsky, PhD, a clinical psychologist, emphasizes the need for rigorous research to accurately detect and diagnose chronic traumatic encephalopathy (CTE) during life, enabling the development of effective prevention and treatment strategies.

What Comes Next: Monitoring and Intervention

The researchers emphasize the importance of continued research to identify individuals at greatest risk and to develop interventions to protect brain health. Future studies should explore the role of individual risk factors, such as genetics and medical comorbidities, and investigate potential therapeutic targets, such as inflammation.

Clinicians should remain vigilant for symptoms of cognitive or emotional difficulties in former athletes and consider comprehensive neurological evaluations when appropriate. Recognizing the potential link between past head impacts and current symptoms can guide more informed management and support.

As Breton Asken, PhD, one of the study’s co-authors, notes, these findings can help “improve earlier detection and identify who is at greatest risk before too much brain change has occurred.”

For more information, Robert Glatter, MD, can be reached at [email protected].