Why footballers are more at risk of Parkinson’s and dementia

BarcelonaFew televised images are more distressing than that of a football player lying on the turf after being hit in the head on a defensive tackle. And there is none more euphoric than a header that goes on the scoreboard in the last minutes of the match. Although football is played predominantly with the feet, the head plays a very important role. Now, a retrospective study by the Hospital Clínic de Barcelona warns of the serious consequences that repeated blows can cause in professional footballers decades after retiring, which can start with a sleep disorder and, in some cases, lead to in a neurodegenerative disease such as dementia. According to the authors, having played football cannot be considered a risk factor as such, at least for the time being, for these pathologies based only on the results of their study, but they do warn that the proportion of ex-football players affected by any of both diseases is significant with respect to the general population and this line of research requires deeper analyses.

The research was based on information from 228 men, six of whom had played association football between the 1960s and 1970s, and was published in the journal Journal of Neurology. All of them have been treated at the Clinic’s Sleep Disorders center between March 1994 and March 2022. The hypothesis of the Catalan researchers was that playing football professionally is a factor that contributes to the predisposition to suffer from a sleep disorder they are in the REM phase, which is associated with poor rest in people over 50 years old and in which the affected person moves abruptly during sleep because they suffer from nightmares in which they feel attacked or chased and have to run away. In some cases they may scream, cry or kick and punch and therefore there is no muscle relaxation.

In this nearly 30-year study period, 338 people were diagnosed with REM sleep disorder at the Clinic, 228 of whom were men, and one-third developed a neurodegenerative disease after a 7-year follow-up period. The neurologist at the Hospital Clínic and coordinator of the study, Àlex Iranzo, has explained that behavior disorder during REM sleep is the anteroom and the first manifestation of neurodegenerative diseases such as Parkinson’s or dementia with Lewy bodies, in which an accumulation of deposits of the alpha-synuclein protein is observed (how and why they are overproduced is not yet known). The correlation is striking: 25% of people with disturbed REM sleep suffer from dementia within five years; after 10 years, the figure increases to 75%. And one of the causes of this sleep disorder is associated with craniocerebral trauma, in which there is a progressive neuronal loss.

Higher percentage than the rest of the population

Soccer players have a 50% chance of sustaining at least one concussion over the course of a decade’s career, either through collisions with other players or against the goal post or the ball itself. Therefore, the researchers wanted to identify how many of these patients who came to the clinic for a REM sleep disorder had been professional soccer players. “Our hypothesis is simple: we associate having played football professionally and receiving repeated blows to the head with the development of REM disorder and dementia,” sums up Iranzo. Of the 228 men treated at the Clinic, six had played federated football between the ages of 18 and 36 and had an average career of 13 years. “Two had played in the First Division, two in the Second and two in the Third. Three were forwards, two defenders and one was a goalkeeper. Half of them suffered a concussion during a match,” the neurologist explains.

At the time of diagnosis, all retired soccer players in the study group (six) had biomarkers of neurodegenerative diseases: five ended up developing Parkinson’s (three), and two, dementia with Lewy bodies, four years after diagnosis of the disorder. they are REM and 44 since they retired from football. Comparing this data with the rest of the group (in which none turned out to have been footballers) and the general population (in which 0.062% had been footballers between the 1960s and 1970s), the researchers found that the percentage of professional soccer players who have REM sleep disorder is higher than the general population. “This would explain why in football and other contact sports professional athletes can end up developing different types of neurodegenerative diseases a few decades after retiring”, points out Àlex Iranzo, who adds that “statistically” it is a viable association, if well it must be possible to validate with more studies.

The neurological impact on players of contact sports (football, clear, but also hockey or rugby) has been studied more and more and the highest exponent is boxing, from which a specific pathology was identified, which is pugilistic dementia. A few weeks ago the magazine The Lancet published a study in which it was found that footballers are more likely to develop neurodegenerative diseases than the rest of the population after analyzing 6,007 Swedish footballers who played between the years 1924 and 2019. Specifically, it noted that 537 were diagnosed with a dementia, 9%. The control group (non-football players) was 56,168 people and 3,485 received a similar diagnosis, that is, 6.2%. Also in 2019, a study with Scottish players revealed that former footballers had a 3.4 times higher risk of dying from neurodegenerative diseases than the rest of the population. These two studies are “two sides of the same coin,” according to Iranzo.

Limit hitting on minors

The specialist in sports medicine at the Gil Rodas Clinic has remarked that all these studies on contact sports corroborate the need to apply preventive measures to reduce blows to the head. “We are dealing with a possible risk factor for neurodegenerative diseases, which is trauma. Every weekend, athletes suffer blows to the head, but in the past we have greatly minimized these injuries,” he says. At the moment, there is no standardized protocol by the bodies beyond stopping the game for three minutes to assess the injury and decide whether to remove the player from the field of play. “Before both the player and the coach wanted to continue playing, but now there is more awareness. We have the challenge of teaching the clubs andstaff of the significance of these strikes, they must understand it,” says Rodas.

For example, he says, it would be positive if the player did not return to the field until six days after the hit. In this gradual recovery, it is necessary to wait 24 hours and, if there are no symptoms, start from the second day with only aerobic exercise (such as cycling) and gradually increase the physical activity. The expert also positively evaluates initiatives such as those already applied by the English football federation to limit minors head-butting during training.