Researchers from the University of Glasgow, Boston University and the University of Sydney examined the brain tissue from 31 former rugby players to assess their risk of developing chronic traumatic encephalopathy (CTE).
CTE is a degenerative brain condition which has been shown to be, at least in part, a result of exposure to repeated head impacts and head injuries. It has been detected following postmortem examination of the brains of former contact sports participants, including football, American football, boxing and rugby.
The study looked at the results of detailed postmortem brain examinations of 31 former amateur and elite rugby union players whose brains were donated for research purposes to one of three leading centers in the UK, United States, and Australia.
CTE was found in around two thirds (68 per cent) of the brains examined, and in both amateur and elite players.
The risk of CTE pathology was also associated with the length of a rugby player’s career, with each addition year of play adding 14 per cent to the risk of CTE.
A player’s position did not appear to influence the risk of developing the condition, according to the study.
The average rugby career length in the study was around 18 years, with an equal number of forwards and backs. Three-quarters (74 per cent) of those surveyed played rugby exclusively as amateurs, while the remainder reached elite level.
Rugby union is known to have a high risk of mild traumatic brain injury (concussion), with injury rates highest in the professional game.
Former England hooker Steve Thompson revealed in 2020 that he could not remember winning the World Cup with England in 2003 after being diagnosed with dementia.
He is among a string of ex-players seeking damages from world rugby's governing body, claiming that he suffered permanent brain damage as a result of playing the game.
Professor Willie Stewart, consultant neuropathologist and lead author of the study, said: “In this study, we have combined the experience and expertise of three leading international brain banks to look at CTE in former rugby players.
“These results provide new evidence regarding the association between rugby union participation and CTE. Specifically, our data show risk is linked to length of rugby career, with every extra year of play increasing risk. Based on this it is imperative that the sport's regulators reduce exposure to repeated head impacts in match play and in training to reduce risk of this otherwise preventable contact sport related neurodegenerative disease.”
Ann McKee, director of Boston University's CTE Center and UNITE brain bank, and co-author of the study, said: “CTE is a preventable disease; there is an urgent need to reduce not only the number of head impacts, but the strength of those impacts, in rugby as well as the other contact sports, in order to protect and prevent CTE in these players.”
Prof Tara Spires-Jones, President of the British Neuroscience Association, said the study “adds to the existing literature indicating that playing contact sports increases the risk of neurodegenerative diseases in elite players”.
“While this current study did show some people who played amateur rugby had brain pathology, the strongest data linking contact sports to neurodegeneration still come from professional or elite players. Brain injury, such as those that can occur in contact sports, are associated with an increased risk of dementias later in life, however, physical activity generally is associated with lower risk of dementias. So while it is a good idea to protect your brain by avoiding head injury, it is also very important to exercise.”
The study was published in the journal Acta Neuropathologica on Tuesday.