Why sports stars who head the ball are much more likely to die of Alzheimer’s, Parkinson’s and motor neurone disease

“The best way of telling whether somebody might have CTE is to ask them the question ‘have you ever played football?’ or ‘have you ever played rugby?’ Because if you’re a professional footballer and you have dementia, then your chances of having CTE in your brain are very high,” says Stewart.

Since 2008, Ann McKee, a professor of neurology and pathology at Boston University School of Medicine, has been inviting former athletes to participate in research studies to learn how to diagnose and treat CTE. In 2023, McKee and colleagues analysed the donated brains of 376 former National Football League (NFL) players, and found a whopping 91.7% had CTE.

Heading the ball is also linked to other degenerative brain conditions

This cohort included former Philadelphia Eagles quarterback Rick Arrington, who played for the team between 1970-73, and former Kansas City Chiefs defender Ed Lothamer, who played in the very first Super Bowl. This does not represent the true risk of developing CTE amongst American football players, as people who suspect they may have the condition may be more likely to donate their brain to science. However for context the prevalence of CTE in the general population is thought to be less than 1%. McKee has also diagnosed CTE in former baseball players, cyclists and ice hockey stars. In all cases the common denominator was repeated knocks to the head.

However, it isn’t just CTE. Heading the ball is also linked to other degenerative brain conditions too. As part of the ongoing Football’s InfluencE on Lifelong health and Dementia risk (Field) study that he is running, in 2019, Stewart and his team examined the health records of nearly 8,000 Scottish former professional football players and compared them to 23,000 members of the general population.