New JAMA Study Confirms Dose-Response Link Between Years of Football and Late-Life Cognitive Decline

A new JAMA study finds a dose-response link between years of American football and late-life cognitive decline. Discover how career length impacts brain health.

By: AXL Media

Published: Feb 27, 2026, 1:14 PM EST

Source: The information in this article was sourced from JAMA Network Open

Quantifying the Neurological Cost of the Gridiron

The long-term health implications of American football have come into sharper focus with the release of a comprehensive peer-reviewed study led by Michael L. Alosco, PhD, of Boston University. The research, published in JAMA Network Open, provides robust evidence that participation in the sport is significantly associated with worse cognitive and neuropsychiatric outcomes as players age. By analyzing a broad cohort of former athletes, the study aims to move beyond anecdotal evidence to establish a scientific framework for assessing the neurological risks inherent in contact sports.

A Clear Dose-Response Relationship

The most striking finding of the research is the "dose-response" association regarding the duration of a player’s career. The data suggests that the risk of developing cognitive impairments—such as memory loss and executive dysfunction—increases incrementally with every additional year of play. This relationship underscores that the cumulative impact of repetitive head strikes, rather than a single isolated concussion, may be the primary driver of late-life neurological decline. Clinicians can now use this "years of play" metric as a more accurate predictor of a patient's future symptom profile.

Level of Play as a Risk Multiplier

In addition to the length of a career, the study highlights that the intensity and level of competition significantly influence neuropsychiatric function. Former professional and collegiate players exhibited more pronounced deficits compared to those who only participated at the high school level. This suggests that the increased speed, force, and frequency of collisions at elite levels of the sport act as a catalyst for more severe brain trauma. The findings provide critical context for researchers attempting to differentiate between the standard aging process and sport-related neurodegeneration.