At Least 1 in 4 Former N.F.L. Players End Up With C.T.E.: What New Research Means for Athlete Brain Safety

A landmark study published in The BMJ has put a stark number on what many sports families and medical professionals have long feared. Researchers examining former N.F.L. players found that at least 24.5%—or nearly 1 in 4—had Chronic Traumatic Encephalopathy (C.T.E.) at their time of death.

As reported by The New York Times, scientists analyzed every former N.F.L. player who passed away between 2016 and 2021—878 individuals in total. Out of that complete group, 215 cases were pathologically confirmed to have C.T.E.

Because hundreds of brains in that group were never donated or examined post-mortem, experts emphasize that 24.5% is actually a conservative baseline. The real number is likely much higher.

The Biggest Risk Factor Isn’t What Most People Think

When people think of head injuries in sports, they usually picture violent, highlight-reel concussions. But researchers from Mass General Brigham, Boston University, and the UNITE Brain Bank discovered that the single biggest predictor of C.T.E. isn’t just documented concussions.

It is cumulative force—the total buildup of thousands of small, repeated hits (subconcussive impacts) to the head over years of playing tackle football.

These repetitive hits add up long before an athlete ever reaches the pros. That means risk management has to start much earlier than college or the N.F.L.

What Is C.T.E. and What Are the Warning Signs?

C.T.E. is a progressive brain disease linked to repetitive head trauma. Right now, it can only be definitively diagnosed after death through brain tissue analysis. Over time, repeated hits cause abnormal proteins called tau to build up in the brain, blocking normal nerve communication and changing how a person thinks, feels, and behaves.

Common Symptoms of Long-Term Brain Trauma Include:

• Cognitive decline: Memory loss, executive function breakdown, confusion, and difficulty focusing or planning.

• Mood and behavioral changes: Severe mood swings, sudden irritability, impulsivity, depression, and substance dependency.

• Neurological signs: Chronic headaches, motor skill issues, paranoia, and severe personality shifts.

Health experts in the study pointed out that this level of neurological risk is practically unheard of in modern workplaces. Yet because C.T.E. stems directly from physical exposure, it is also preventable.

How We Protect Athletes at Every Level

You don’t have to give up sports to protect your brain, but we do need to change how we handle head impacts.

At Concussion Management of New York, we specialize in comprehensive concussion protocols, baseline testing, and post-injury care for athletes of all ages across New York. Reducing the long-term risk of neurodegenerative disease starts with smart, proactive decisions today.

Key Steps for Parents, Coaches, and Players to Improve Safety and Prevention:

• Stop playing through hits: Never let an athlete return to the field with a suspected head injury or after taking a hard, non-concussive hit that leaves them dazed.

• Cut down contact during practice: Limit full-contact drills during team practices to dramatically reduce an athlete’s career hit count.

• Follow proper recovery protocols: Allow the brain full physiological recovery time after any head trauma under the supervision of trained concussion specialists.

If you or a loved one are concerned about lingering post-concussion symptoms or the long-term effects of athletic head injuries, our clinical team is here to help.

Study Details & Medical Reference

• Publication: The BMJ (published online August 25, 2026)
• Lead Author: Dr. Daniel Daneshvar, Chief of Brain Injury Rehabilitation at Spaulding Rehabilitation Hospital and Associate Professor at Harvard Medical School
• Research Institutions: Mass General Brigham, Boston University, and the UNITE Brain Bank
• Study Population: Post-mortem brain analyses of 878 former N.F.L. players who passed away between 2016 and 2021