Elite male footballers are more likely to develop dementia, says study in The Lancet Public Health
Elite male footballers were 1.5 times more likely to develop a neurodegenerative disease when compared to population controls, according to an observational study published in The Lancet Public Health.
Among male footballers playing in the Swedish top division, 9 per cent (537 out of 6,007) were diagnosed with neurodegenerative disease, compared to 6 per cent (3,485 out of 56,168) population controls.
The footballers played at both amateur and professional levels. Many of the players from Sweden’s top division were competing at the highest international level. However, due to ideals of sportsmanship and amateurism, footballers were not employed on salaries until the late 1960s.
Lead author Peter Ueda, an assistant professor at Karolinska Institutet in Stockholm, said: ‘While the risk increase in our study is slightly smaller than in the previous study from Scotland, it confirms that elite footballers have a greater risk of neurogenerative disease later in life. As there are growing calls from within the sport for greater measures to protect brain health, our study adds to the limited evidence-base and can be used to guide decisions on how to manage these risks.'
The study used Sweden’s national health registers to look for records of neurodegenerative disease (diagnoses, deaths, or use of prescription drugs for dementia) in 6,007 male football players who had played in the Swedish top division from 1924 to 2019. It compared players’ risk of neurodegenerative disease with population controls, who were people matched with football players according to sex, age, and region of residence. The analysis broke down the risk for different neurogenerative conditions, including Alzheimer’s and other dementias, motor neurone disease, and Parkinson’s disease. It also compared the risks between outfield players and goalkeepers.
Overall, football players had a 1.5 times increased risk of neurogenerative disease compared to controls. Nine per cent (537 out of 6,007) of football players compared to 6 per cent (3,485 out of 56,168) of controls were diagnosed with neurodegenerative disease.
As there are growing calls from within the sport for greater measures to protect brain health, our study adds to the limited evidence-base and can be used to guide decisions on how to manage these risks [Peter Ueda]Lifetime risks could rise
The authors caution that although 9 per cent of football players and 6 per cent of controls were diagnosed with neurodegenerative disease during their study, most participants were still alive at the end of data collection, so the lifetime risk of developing neurodegenerative disease for both groups are likely to be higher.
The risk of neurodegenerative disease was 1.5 times higher for outfield players compared to controls but was not significantly higher for goalkeepers compared to controls. Accordingly, in a direct comparison, outfield players had a 1.4 times higher risk of neurodegenerative disease compared to goalkeepers.
Dr Ueda added: ‘Importantly, our findings suggest that goalkeepers don’t have the same increased risk of neurodegenerative disease as outfield players. Goalkeepers rarely head the ball, unlike outfield players, but are exposed to similar environments and lifestyles during their football careers and perhaps also after retirement. It has been hypothesised that repetitive mild head trauma sustained through heading the ball is the reason football players are at increased risk, and it could be that the difference in neurodegenerative disease risk between these two types of players supports this theory.’
Football players had a 1.6 increased risk of Alzheimer’s disease and other dementias compared to controls – with 8 per cent (491 out of 6,007) of footballers being diagnosed with the condition compared to 5 per cent (2,889 out of 56,168) of controls.
There was no significant risk increase for football players versus controls observed for motor neurone disease, which includes ALS (amyotrophic lateral sclerosis).
The risk of Parkinson’s disease was lower among football players. Overall mortality was slightly lower among footballers compared to the control group (40 per cent versus 42 per cent).
Physical activity is associated with a lower risk of dementia, so it could be hypothesised that the potential risks from head impacts are being somewhat offset by having good physical fitness [Björn Pasternak]
Some risks may be offset by good fitness levels
Co-author Björn Pasternak, a senior researcher at Karolinska Institutet, said: ‘The lower overall mortality we observed among footballers indicates that their overall health was better than the general population, likely because of maintaining good physical fitness from frequently playing football.
'Physical activity is associated with a lower risk of dementia, so it could be hypothesised that the potential risks from head impacts are being somewhat offset by having good physical fitness. Good physical fitness may also be the reason behind the lower risk of Parkinson’s disease.’
Some limitations
The authors acknowledge that their study had some limitations and say the findings’ generalisability to footballers playing today is uncertain. As neurodegenerative disease usually occurs later in life, most of those in the study who were old enough to have developed one of these conditions played elite football during the mid-20th century. Since then, football has changed in ways that reduce the risk of neurodegenerative disease: for example, switching from leather to synthetic balls (that do not soak up water and become heavier), having more rigorous training and better equipment, or switching towards a playing style that is associated with less head trauma.
On the other hand, the risk might be higher among footballers today who train and play more intensely from a young age. As the study only looked at male elite footballers, its generalisability to female elite players and to male and female amateur and youth players is uncertain.
Factfile
There have been growing concerns about exposure to head trauma in football in recent years and whether it can lead to increased risk of neurodegenerative disease later in life. A study conducted in Scotland suggested that footballers were 3.5 times more likely to develop neurodegenerative disease. See: https://www.nejm.org/doi/full/10.1056/NEJMoa1908483
Following this evidence, certain footballing associations implemented measures to reduce heading in younger age groups and training settings. UEFA (Union of European Football Associations) and the British football federations updated their guidelines to reduce exposure to heading among youth players. Limits for the number of headers that involve higher forces, such as those following a long pass or from corners kicks, were later introduced for adult amateur players and professional players in England.
To see the full version of the article – titled Neurodegenerative disease among male elite football (soccer) players in Sweden: a cohort study – visit: https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(23)00027-0/fulltext
Author: Ian A McMillan
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