A new study that included 6,007 male soccer players who played in the Swedish top division between 1924 and 2019 suggests they were 1.5 times more likely to develop neurodegenerative diseases compared to population controls.
Elite soccer players had a higher risk of developing Alzheimer’s disease and other dementias, but their risk of motor neurone disease (including ALS) was not increased , and their risk of Parkinson’s disease was lower compared to men. controls.
Unlike field players, goalkeepers (goalkeepers) did not have an increased risk of dementia, supporting the hypothesis that mild impacts to the head when heading the ball could explain the increased risk in field players.
Elite male soccer players were 1.5 times more likely to develop neurodegenerative diseases compared to population controls, according to an observational study published in the journal The Lancet Public Health .
Among male footballers playing in the Swedish top division, 9% (537 of 6,007) were diagnosed with a neurodegenerative disease, compared to 6% (3,485 of 56,168) of population controls.
The footballers were both amateurs and professionals. Sweden was a prominent footballing nation during the 20th century and many of the top division players competed at the highest international level. However, due to ideals of sportsmanship and amateurism, football clubs in Sweden were not allowed to pay salaries to their footballers until the late 1960s.
In recent years, there has been growing concern about exposure to head trauma in football and whether it may lead to an increased risk of neurodegenerative diseases later in life. A previous study from Scotland suggested that footballers were 3.5 times more likely to develop neurodegenerative diseases. Following this evidence, certain football associations implemented measures to reduce heading in younger age groups and training environments.
Peter Ueda, assistant professor at Karolinska Institutet, Sweden, says: "While the increased risk in our study is slightly lower than in the previous study from Scotland, it confirms that elite footballers have a higher risk of neurodegenerative disease later in life. life. “As there are growing calls within sport to take greater steps to protect brain health, our study adds to the limited evidence base and can be used to guide decisions about how to manage these risks.”
The study used Sweden’s national health registries to search for records of neurodegenerative diseases (diagnoses, deaths or use of prescription dementia drugs) in 6,007 male soccer players who had played in the Swedish top division between 1924 and 2019. It compared the players’ risk of neurodegenerative disease with population controls, who were people matched with soccer players according to sex, age and region of residence. The analysis broke down the risk of different neurodegenerative conditions, including Alzheimer’s disease and other dementias, motor neurone disease, and Parkinson’s disease. He also compared the risks between outfield players and goalkeepers.
Overall, soccer players had a 1.5-fold increased risk of neurodegenerative disease compared to controls. 9% (537 of 6,007) of soccer players compared to 6% (3,485 of 56,168) of controls were diagnosed with a neurodegenerative disease.
The authors note that although 9% of the soccer players and 6% of the controls were diagnosed with a neurodegenerative disease during their study, most participants were still alive at the end of data collection, so it is The lifetime risk of developing a neurodegenerative disease for both groups is likely to be higher.
The risk of neurodegenerative disease was 1.5 times higher for field players compared to controls, but was not significantly higher for goalkeepers compared to controls. Consequently, in a direct comparison, field players had a 1.4 times higher risk of neurodegenerative disease compared to goalkeepers. See Table 3 for more details comparing results between outfield players, goalkeepers, and population controls.
Peter Ueda adds: “Importantly, our findings suggest that goalkeepers do not have the same increased risk of neurodegenerative diseases as field 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 hypothesized that repetitive mild head trauma sustained when heading the ball is the reason why soccer players are at higher risk, and it could be that the difference in risk of neurodegenerative diseases between these two types of players support this theory.”
Soccer players had a 1.6 times higher risk of Alzheimer’s disease and other dementias compared to controls: 8% (491 of 6,007) of soccer players were diagnosed with the condition compared to 5% (2,889 of 56 168) of the controls.
No significant increased risk was observed for American football players compared to controls for motor neurone disease, which includes ALS. The risk of Parkinson’s disease was lower among soccer players (see Table 2 for more details). Overall mortality was slightly lower among soccer players compared to the control group (40% vs. 42%).
Björn Pasternak, senior researcher at Karolinska Institutet, says: “The lower overall mortality we observed among football players indicates that their general health was better than that of the general population, probably because they maintain good physical fitness by playing football frequently. . Physical activity is associated with a lower risk of dementia, so it could be hypothesized that the potential risks of head impacts are offset to some extent by good physical condition. "Good physical fitness may also be the reason behind the lower risk of Parkinson’s disease."
The authors discuss some limitations of their study. The generalizability of the findings to footballers playing today is uncertain. Since neurodegenerative disease typically occurs later in life, most of the players in the study who were old enough to have developed one of these conditions played elite soccer in the mid-20th century. Since then, football has changed in many ways that may affect the risk of neurodegenerative diseases. It may be that switching from leather to synthetic balls (which do not absorb water and become heavier), having more rigorous training and better equipment, or switching to a style of play associated with less head trauma may have reduced the risk. On the other hand, the risk could be greater among soccer players who today train and play more intensely from an early age. The study also analyzed only elite male soccer players,
Final message In this nationwide cohort study, male soccer players who had played in the Swedish top division had an increased risk of neurodegenerative disease compared to general population controls. The increased risk was seen for Alzheimer’s disease and other dementias (but not other types of neurodegenerative diseases) and among field players, but not goalkeepers. Although our study confirms that former elite football players have a higher risk of neurodegenerative disease, the association was smaller in our study than that observed in a previous Scottish study and was only observed for Alzheimer’s disease and other types of dementia, but not for the motor neuron. disease or Parkinson’s disease. |
This study was funded by Karolinska Institutet (The Strategic Research Area in the Epidemiology Program), the Swedish Research Council for Sports Science, the Folksam Research Foundation, the Hedberg Foundation, Neurofonden, the Åhlen Foundation. It was carried out by researchers from the Karolinska Institutet.
