by Aine Fox
A potential cause of dementia thought to arise from blows to the head has, for the first time, been confirmed in a group of retired footballers, prompting calls for more research into a long-suspected issue in the sport.
The findings, from a small study of former players, suggest a possible link between playing football and developing such conditions later in life, researchers said.
The results provide a platform for a “pressing research question” on whether dementia is more common in footballers than the general population, said Dr Helen Ling, lead author of the UCL Queen Square Brain Bank study.
The brains of six of the 14 retired players involved in the research underwent autopsies and four were found to have chronic traumatic encephalopathy (CTE) pathology, while all six had signs of Alzheimer’s disease. CTE can cause dementia and, like Alzheimer’s, is characterised by a build-up of abnormal tau protein in the brain.
The rate of CTE detected in the footballers’ brains was greater than the 12% average found in a previous study which looked at 268 brains from the general population.
The results show more research is urgently needed in the area, Prof Huw Morris of UCL Institute of Neurology said, but he cautioned the risk for people who enjoy playing football in their spare time is likely to be low.
“We do not yet know exactly what causes CTE in footballers or how significant the risk is,” he said.
“Major head injuries in football are more commonly caused by player collisions rather than heading the ball.
“The average footballer heads the ball thousands of times throughout their career, but this seldom causes noticeable neurological symptoms.”
He added: “Of course, any kind of physical activity will be associated with health risks and benefits and it is well-established that playing sports can significantly improve physical and mental health.
"Of the risk to people who may step out for a kickabout in the near future he said: “the risk is extremely low”.
The ex-players involved in the study, 12 of whom eventually died of advanced dementia, all began playing football and heading the ball when they were children or teenagers and continued for an average of 26 years.
They were all referred to the Old Age Psychiatry Service in Swansea, Wales between 1980 and 2010.
Consultant psychiatrist Dr Don Williams, who ran the study from the Swansea service, said he was motivated to do so after being approached by a man whose footballer father had been diagnosed with dementia, and who wanted to know if headers could be the cause.
He said: “As a result I looked out for men with dementia and a history of playing soccer, followed them up, and where possible arranged for post-mortem studies to be carried out.
“The results suggest that heading the ball over many years, a form of repetitive sub-concussive head injury, can result in the development of CTE and dementia. Thus the original suggestion has been shown to be of merit and worthy of further investigation.”
The scientists acknowledged the size of the study was small, and appealed to people to remain open-minded when it comes to presenting themselves for research.
Prof Morris said: “I think people being involved in research is a good thing and would encourage people to consider that.”
Dr Ling said the research, published in the journal Acta Neuropathologica and funded by The Drake Foundation is important, but added more is needed for definitive results.
“Previous studies have shown that the risk of Alzheimer’s is increased in people with previous head injuries.
"On the other hand, the risk of dementia is also increased with age and we don’t know if these footballers would have developed Alzheimer’s disease anyway.”
“The most pressing research question is therefore to find out if dementia is more common in footballers than in the normal population.”