Professional soccer players are more predisposed to developing REM sleep disorders, the first manifestation of neurodegenerative diseases such as Parkinson's or dementia, according to a study by the Hospital Clínic-Idibaps. Repeated blows to the head can cause neuronal loss and the appearance of protein deposits responsible for neurodegenerative pathologies.
The study carried out in Barcelona, published in the Journal of Neurology, confirms the results of previous research on Scottish and Swedish football. In the latter case, it is concluded that professional soccer players are 1.5 times more likely to develop a neurodegenerative disease compared to population controls.
A team of researchers led by the neurologist Álex Iranzo analyzed the characteristics of the 338 people (228 men) treated at the Clínic's center for sleep disorders between 1994 and 2022. 34% of the men developed a neurodegenerative disease after 7 years.
Six of the men (2.63%) had been professional soccer players for an average of 14 years, between the ages of 18 and 36. From the time of their retirement to the diagnosis of REM sleep disorder, 40 years elapsed.
The study group has been compared with a control group of 228 individuals of the same age without any professional soccer player, and with the general population, in which 0.062% appear as professional soccer players.
Thus, the researchers detail that the percentage of soccer players in the group of REM sleep disorders (prelude to neurodegenerative diseases) is higher (2.63%) than in the control group (0%) and than in the soccer players among the general population (0.062%).
All six soccer players in the study group had disease biomarkers related to alpha-synuclein deposits, and five went on to develop Parkinson's or Lewy body dementia four years after REM sleep diagnosis and 44 years after retirement.
"The professional practice of soccer would not be the cause or a risk factor, but an association that still needs to be explained and still needs to be replicated with other investigations," explained Iranzo, who has included genetic and environmental factors, among others, among the possible causes. .
Although the association between neurodegenerative diseases and head injuries leads researchers to speculate that "in the retired soccer players in the study group, exposure to these repeated blows to the head may be one of the contributing factors." REM sleep disorder and then dementia.
Educating in fair play, implementing more important penalties or carrying out exercises to strengthen the neck muscles that reduce the impact on the head are some of Iranzo's recommendations to avoid repeated blows or their consequences.
According to Gil Rodas, head of the Sports Medicine unit at the Clínic and Sant Joan de Déu, sports institutions are increasingly aware that head injuries are a risk factor for neurodegenerative disease. A prevention that is reflected in initiatives such as that of the English Federation to limit headbutts in children's training sessions.
“More studies are needed to determine that with preventive strategies you reduce the magnitude of the problem, and this will take years, but it is good that the institutions have seen that it is an important issue. High-level sport also has to take care of the health of the athletes”, stated Dr. Roda.
