Today’s news media are abuzz with reports, and the blogosphere with opinion, about a new phone survey on dementia commissioned by the National Football League. Conducted by the University of Michigan's Institute for Social Research, the survey at this point is neither peer reviewed nor published, but apparently was leaked to The New York Times. According to the Times story, the survey indicates that diagnoses of Alzheimer disease or other memory disorders among 1,063 retired NFL players greatly exceeded the rate expected for their age groups in the general population—by up to 19-fold among men in their forties and fifties and by fivefold among players older than 50. Despite the technical limitations of the study, it represents an acknowledgement by the league that there is a connection.

The survey comes in the wake of pressure from scientific studies and media reports that has been building over the past two to three years. The cumulative evidence, together with some high-profile individual cases, highlighted the need to study the possible risk of long-term neurologic consequences from repeated blows to the head and to institute protective measures. The Alzforum has covered the topic in the news and with a Live Discussion that was attended by, among others, Ira Casson, co-chairman of the NFL’s concussions committee (search for Casson in transcript). Casson in the past has downplayed evidence linking football and dementia. The NFL is conducting its own study; today’s NYT story notes that Dr. Casson is conducting all neurologic examinations in this study.

Newspapers, television stations, and blogs across the country picked up the NYT report. A story in the Baltimore Sun notes that ARF advisor Peter Davies, a leading pathologist in the field of neurodegenerative diseases, played a role in swaying the NFL’s concussion committee to rethink its stance after viewing slides with Bennet Omalu and Julian Bailes, two of the physician-researchers who study the issue (see prior ARF related news story). A story on NBC Miami mentions local NFL players who are deciding to donate their brains and spinal cords to a research program at Boston University’s Center for the Study of Traumatic Encephalopathy (see ARF related news story; LA Times story). And coaches and team doctors outside of professional football are taking sports concussions more seriously, too. On September 15, National Public Radio broadcast a report about schools instituting concussion management programs.—Gabrielle Strobel.


  1. I offer my comments with the caveat that I have not seen the study and the study has not been peer reviewed. However, the findings as
    reported by The New York Times are not surprising, and are completely
    congruous with our observations at the Boston University Center for
    the Study of Traumatic Encephalopathy. The brains of all seven NFL
    players that we have examined have had a distinctive, widespread tau
    neurofibrillary degeneration distributed throughout the cerebral
    cortex, deep nuclei, and brainstem. The neurofibrillary degeneration
    found in the NFL players is identical in all respects to the pattern
    of tau neurofibrillary degeneration seen in retired boxers, commonly
    known as dementia pugilistica or, more recently, chronic traumatic
    encephalopathy (CTE).

    This pattern of tau degeneration in CTE is
    unique and entirely distinct from that found in Alzheimer disease,
    other tauopathies, or normal aging. Furthermore, we have found this
    strikingly abnormal tau deposition in every brain from a former NFL
    player that we have had the opportunity to examine despite his
    relatively young age at death (mean = 46 years). So the observation
    that memory loss or cognitive impairment is found more frequently in
    retired NFL athletes is entirely what we would expect given our
    neuropathological findings, and we will also not be surprised if we
    find the same tau neurofibrillary neurodegeneration in the brains of
    individuals who suffer repeated mild head injury in association with
    military service, motor vehicle crashes, or accidental falls.

    Currently, CTE can only be diagnosed at autopsy; very little is known
    about its clinical course, and there is no method of early detection
    by neuroimaging or biomarker assay. This report, combined with our
    observations, underscores the need for comprehensive longitudinal
    assessment of athletes and other individuals who suffer mild head
    injury so that we may find a potential therapy for early intervention,
    and reduce, or entirely prevent, this devastating disorder.

  2. I offer my comment with the caveats expressed by my colleague Dr. Ann McKee. From the perspective of someone involved in the research and who also has been exposed to similar trauma as the players in the study, the findings are not surprising, but at the same time very alarming. I was most surprised by the fact that less than 2 percent of the under 50 group had been diagnosed with memory-related diseases. Due to the evolution of the way the game has been played and the “bigger, stronger, faster” nature of modern players, I believe that the current generation of athletes, despite the new concussion awareness of the last few years, is experiencing more brain trauma than any previous generation. Considering that every brain Dr. McKee has analyzed, professional or college, has had tau degeneration, with a mean age of 46, I expect more and more players will continue to show clinical symptoms early and be diagnosed with these disorders before the age of 50. Although a risk factor of 19 times versus the normal population seems astronomical, I wouldn't be surprised to see it get worse.

  3. The concept of mechanical injury being responsible for Alzheimer’s is consistent with the hyponatremia hypothesis I left on the Hypothesis Factory a while ago. In my hyponatremia hypothesis, repeated osmotic swelling of the brain rather than impact to the skull causes mechanical injury.

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Webinar Citations

  1. Sports Concussions, Dementia, and APOE Genotyping: What Can Scientists Tell the Public? What’s Up for Research?

News Citations

  1. Butting Heads—Autopsies Fuel Debate on Football and Neurodegeneration
  2. Research Brief: Athletes’ Brains to Help Map Concussion Effects

Other Citations

  1. Peter Davies

External Citations

  1. Times story
  2. Baltimore Sun
  3. story on NBC Miami
  4. LA Times story
  5. report

Further Reading