Summary: A multi-institutional team reviewed medical and mortality records spanning six decades and found that former National Football League (NFL) players have markedly higher rates of death from neurodegenerative diseases than the general population. Although NFL veterans show lower overall mortality, they are about four times more likely to die from neurodegenerative conditions—including dementia and Parkinson’s disease—than comparable members of the public. The findings reveal a robust dose-response relationship between years played and brain-related mortality and introduce a new epidemiological concept explaining why this elevated risk is especially striking.
Key Facts
- Fourfold increase in neurodegenerative mortality: Across official causes of death analyzed, NFL veterans had a standardized neurodegenerative mortality ratio of 3.94. This includes a 3.80-fold increase for all-cause dementia and a 3.88-fold increase for Parkinson’s disease.
- STARS effect explained: The researchers describe a Selection Through Athletic Resilience Survivor (STARS) effect: the genetic, medical, behavioral, and socioeconomic advantages that help athletes reach and remain in the NFL also tend to protect them from many common causes of death. The presence of these advantages makes the higher brain disease rates more notable.
- Elevated risk likely underestimated: Because NFL players generally have lower rates of cancer, cardiovascular disease, and suicide—reflecting the STARS effect—the observed fourfold neurodegenerative increase may understate the true neurological harm associated with repetitive head impact exposure.
- Young deaths disproportionately affected: Players who died before age 60 showed more than a 12-fold increase in neurodegenerative mortality compared to age-matched peers in the general population.
- Career dose-response: A clear relationship between career length and risk was observed: players with careers of five seasons or more faced nearly double the neurodegenerative mortality risk compared with players who played one to four seasons, consistent with prior work on chronic traumatic encephalopathy (CTE).
- Comparable to major environmental hazards: Investigators note that the scale of increased dementia risk associated with playing professional football exceeds that of known neurotoxic environmental exposures, such as heavy lead, which historically raised dementia risk by two- to threefold.
Source: Mass General Brigham
A collaborative study from Mass General Brigham, Boston University, and the Concussion & CTE Foundation analyzed a cohort of 19,824 NFL players who appeared in at least one regular- or postseason game from 1960 through 2019. Using National Death Index records and standardized mortality comparisons, the investigators quantified the association between repetitive head impact (RHI) exposure in professional football and subsequent neurodegenerative mortality.
Results are published in eClinicalMedicine.
“This is the clearest population-level evidence we have that NFL players die from neurodegenerative disease at measurably higher rates,” said co-senior author Daniel Daneshvar, MD, PhD, Chair of Physical Medicine and Rehabilitation at Mass General Brigham and Harvard Medical School. “Across every cause of death we examined, NFL players experienced increased dementia and Parkinson’s mortality three to four times above expectation.”
Although age remains the strongest general risk factor for neurodegenerative illness, evidence increasingly links repetitive head impacts to higher incidence. In this comprehensive retrospective cohort, players had lower all-cause mortality overall (reflecting the STARS effect) but substantially raised neurodegenerative mortality. After simulations accounting for competing causes of death, the excess neurodegenerative risk remained approximately threefold.
The risk was particularly striking among younger decedents: those who died before 60 had a more than 12-fold elevation in neurodegenerative mortality. Career length produced a dose-response trend, with five-plus season players showing nearly double the risk of those who played one to four seasons. The pattern aligns with clinical and neuropathological evidence pointing to chronic traumatic encephalopathy (CTE) as a major underlying process.
“A fourfold increase in dementia from an environmental exposure is substantial,” said co-senior author Jesse Mez, MD, MS. “By comparison, historical heavy lead exposure raised dementia risk two- to threefold. These findings place repetitive brain trauma in professional football among the more consequential public health threats to long-term cognitive health.”
Despite the elevated brain-related mortality, NFL players were less likely than the general population to die from cancer, cardiovascular disease, and suicide—reinforcing that this cohort is, overall, healthier but uniquely vulnerable to neurodegenerative outcomes. The STARS effect helps explain why the observed brain disease burden stands out against otherwise favorable health indicators.
Players concerned about memory, cognition, or other neurological symptoms are advised to seek evaluation from clinicians experienced in neurodegenerative disease. Many treatable conditions—such as sleep apnea, nutritional deficiencies, mood disorders, and other medical issues—can produce symptoms that mimic dementia or Parkinson’s and can be managed to improve quality of life. Identifying and addressing modifiable risk factors, optimizing sleep and vascular health, and accessing specialist care can support brain health.
Authorship: Daniel H. Daneshvar, Jesse Mez, Adam J. White, Ann C. McKee, Charlotte B. Luster, Bobak Abdolmohammadi, Brenna Finegan, Michael J. Mastrodicasa, Christopher J. Nowinski, Evan D. Feigel, Eric J. Connors, Craig Rovito, Ross D. Zafonte, Michael L. Alosco, and others.
Disclosures: Study authors disclosed relationships with organizations including the Player Advocacy Committee for the NFL Concussion Settlement, the NFL Players Association (NFLPA) and affiliated programs, World Rugby, World Wrestling Entertainment (WWE), All Elite Wrestling (AEW), and the Professional Footballers’ Association. Full disclosures are reported in the published paper.
Funding: National Institute of Neurological Disorders and Stroke (U54NS115266; U01NS086659), National Institute on Aging (P30AG13846; P30AG072978), and the Maloney/Carpenter Trauma-Related Neurodegenerative Disease Research Fund.
Key Questions Answered
A: The STARS effect explains this paradox. Players who reach the NFL generally have genetic, behavioral, and socioeconomic advantages that reduce many common causes of death. Those protections do not appear to extend to the brain when repetitive head impacts accumulate over years of play, so elevated neurodegenerative mortality is seen despite otherwise favorable health profiles.
A: Investigators note that heavy lead exposure historically increased dementia risk two- to threefold; this study finds a nearly fourfold increase in neurodegenerative mortality associated with NFL play, highlighting the scale of harm linked to cumulative brain trauma in this population.
A: Yes. Past exposures can’t be reversed, but many treatable conditions can mimic or worsen neurodegenerative symptoms. Seek evaluation from specialists in neurodegenerative disease, address sleep and cardiovascular health, treat mood or metabolic issues, and work with clinicians to manage modifiable risk factors to support cognitive function and quality of life.
Editorial Notes
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full by the reporting team.
- Additional context was added by staff to clarify findings and implications.
About this CTE and neurology research news
Author: Tim Sullivan
Source: Mass General Brigham
Contact: Tim Sullivan – Mass General Brigham
Image credit: Neuroscience News
Original research: “Neurodegenerative Mortality Among National Football League Players,” eClinicalMedicine. DOI: 10.1016/j.eclinm.2026.104051. Open access.
Abstract
Neurodegenerative Mortality Among National Football League Players
Background
Prior research links repetitive head impact (RHI) exposure to increased neurodegenerative mortality. This study addressed earlier methodological limitations by analyzing a much larger, fully enumerated cohort of NFL players to quantify the relationship between RHI exposure and neurodegenerative death.
Methods
Researchers conducted a population-based retrospective cohort study of all NFL players who debuted from 1960 to 2019 and played at least one official game. National Death Index records (1979–2023) were matched to player data. Standardized mortality ratios (SMRs) compared observed deaths to an age-, sex-, race-, and calendar-year–standardized general population. Sensitivity analyses and cause-specific hazard simulations evaluated the effect of competing risks.
Findings
Among 19,824 athletes contributing 518,833 person-years (mean follow-up 26.2 years), 1,994 had died. Players showed lower all-cause mortality (SMR = 0.70; 95% CI: 0.67–0.74) but substantially higher neurodegenerative mortality (SMR = 3.94; 95% CI: 3.38–4.56). Specific increases included amyotrophic lateral sclerosis (SMR = 4.55), all-cause dementia (SMR = 3.80), and Parkinson’s disease (SMR = 3.88). After accounting for competing risks, a residual neurodegenerative SMR of 3.04 remained (95% CI: 2.63–3.50).
Interpretation
Neurodegenerative mortality in NFL players was nearly four times higher than in the general population and remained about threefold higher after adjusting for competing risks. These results strengthen evidence that repetitive head impact exposure in professional football contributes to increased neurodegenerative death and cannot be explained solely by differential survivorship.
Funding
This work was supported by the National Institute of Neurological Disorders and Stroke (U54NS115266; U01NS086659), the National Institute on Aging (P30AG13846; P30AG072978), and the Maloney/Carpenter Trauma-Related Neurodegenerative Disease Research Fund.