The football players were both amateur and professional. Sweden was a prominent football nation during the 20th century and many of the players from the top division were competing 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 football players until the late 1960s.

In recent years, there have been growing concerns about exposure to head trauma in football (soccer) and whether it can lead to increased risk of neurodegenerative disease later in life. A previous study from Scotland suggested that footballers were 3.5 times more likely to develop neurodegenerative disease. Following this evidence, certain footballing associations implemented measures to reduce heading in younger age groups and training settings.

Peter Ueda, assistant professor at Karolinska Institutet, Sweden, says, “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.”

https://scienceblog.com/536992/elite-football-players-are-more-likely-to-develop-dementia/