Football and dementia: former players over five times more likely to die of Alzheimer’s, says landmark study
Former professional football (soccer) players are over 3.5-times more like to die due to dementia, and over 5-times more likely to die due to Alzheimer’s disease, than the general population, according to a new landmark study.
The study, Football’s InfluencE on Lifelong health and Dementia risk (FIELD), is centered at Glasgow University (UK) and supported by The Football Association and The Professional Footballers’ Association.
Published today in The New England Journal of Medicine, the retrospective cohort study compared mortality from neurodegenerative disease among 7676 former professional soccer players with that among 23,028 controls from the general population. The sample group was taken from men who played professional football in Scotland between 1900 and 1976, and controls were matched to the players based on sex, age and degree of social deprivation. Causes of death were determined from death certificates, and data on medications dispensed for the treatment of dementia in the two cohorts were also compared.
Retrospective epidemiological analysis demonstrated that a history of playing professional football correlated with a higher risk of dying with neurodegenerative disease – mortality with neurodegenerative disease listed as the primary cause was 1.7% among former soccer players and 0.5% among controls – but this varied according to subtype:
- Mortality with neurodegenerative disease was highest among those with Alzheimer’s disease (hazard ratio [former players vs. controls], 5.07; 95% CI, 2.92 to 8.82; P<0.001)
- Mortality with Parkinson’s disease showed had a two-times higher risk in ex-players versus controls (hazard ratio, 2.15; 95% CI, 1.17 to 3.96; P=0.01)
In addition, the FIELD results showed that dementia-related medications were prescribed more frequently to former players than to controls.
However, the study also notes that mortality from ischemic heart disease was lower in former players than in controls, as was mortality from lung cancer. There was also no significant evidence to suggest that ex-players developed dementia at an earlier age than controls, nor that ex-players who died with dementia died earlier than the control population with dementia.
“This study raises important concerns about neurodegenerative disease in former professional footballers,” commented Neil Pearce, Professor of Epidemiology at London School of Hygiene and Tropical Medicine (UK). “This does not provide definitive evidence, but it does strongly indicate that neurodegenerative disease may be more common in this group.
“As usual, we need further studies that address these issues from different scientific perspectives. The London School of Hygiene and Tropical Medicine is just starting a study of cognitive function in former professional footballers, funded by The Drake Foundation. The study – HEADING – is being conducted in collaboration with Queen Mary University of London (UK), and the Institute of Occupational Medicine (UK), and is being done with the support of The Football Association and The Professional Footballers’ Association.
“Recruitment has just commenced for this new study, which will provide important further evidence to complement the findings that have just been announced from Scotland. In particular, it will inform us as to whether any increased risks of dementia can be identified at an earlier age, using standard tests for cognitive function, which may indicate a tendency to subsequently develop dementia.”
Lauren Pulling, Programme Manager at The Drake Foundation, commented: “These are landmark findings from the FIELD study, which further highlight the previously suspected link between a history of playing professional football and risk of neurodegenerative disease. This is the largest study of its kind, and these retrospective cohort results send a strong message that further research is needed and that sporting protocols may need to adapt in order to support our players.
“We anticipate the results from concurrent studies, which will all help to paint a full picture of the link between football and dementia, including HEADING, which will examine cognitive function in former professional footballers. We must also remember the numerous benefits of taking part in sport, such as improved cardiovascular and respiratory health, which are both also highlighted in FIELD’s results.”
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Source: Mackay DF, Russell ER, Stewart K, MacLean JA, Pell JP, Stewart W. Neurodegenerative disease mortality among former professional soccer players. N. Engl. J. Med. doi:10.1056/NEJMoa1908483 (Epub ahead of print) (2019).