The Scottish study’s findings echo those of previous studies of other former professional athletes, and come at a pivotal time for Big Sport, writes Dylan Cleaver.
The risk of neurodegenerative disease could be twice as high for rugby players – and many times higher for specific conditions – than the general population.
The startling findings come from a study into former Scotland international rugby players and has been published online today in the Journal of Neurology Neurosurgery & Psychiatry.
It found the risk of dementia – a blanket term that covers conditions such as Alzheimer’s disease, Lewy body dementia (LBD) and chronic traumatic encephalopathy (CTE) – was twice as high in the rugby population, while exposure to Parkinson’s disease was three times higher. Instances of motor neurone disease (MND) were a massive 15 times higher.
One of Scotland’s favourite rugby sons, Doddie Weir, is a high-profile advocate for MND research and has been living with the disease for six years.
The study included 412 Scottish former international male rugby players for whom full health and field position data were available, and who were aged at least 30 by the end of 2020.
The players were matched for age, sex and socioeconomic status with 1,236 members of the public.
The study showed that former rugby players were older when they died, reaching an average of nearly 79 compared with just over 76 in the comparison group.
The position the players took on the field, or whether they were forwards or backs, had no bearing on the results.
The authors, including renowned neuroscientist Dr Willie Stewart, said information was not available on rugby career length, on individual histories of head impacts, or on other potential risk factors for dementia.
The study was relatively large and long term, however, and the findings echo those of previous studies of former professional soccer players and former American footballers, say the researchers.
“Notably, in contrast to data from the NFL and soccer, our cohort of rugby players largely comprises amateur athletes, although participating at an elite, international level. In this respect, it is the first demonstration that high neurodegenerative disease risk is not a phenomenon exclusive to professional athletes,” they say.
The study preempts a similar study conducted in New Zealand. That study, led by New Zealand Rugby chief scientist Ken Quarrie and involving the University of Auckland and the Department of Statistics, is in the process of peer review.
It is understood that it will also indicate elevated rates of neurodegenerative disease among former rugby players, although not at rates as stark as the Scotland study.
In recent years there have been several reports into former players suffering from or dying with early onset dementia, including Carl Hayman, who is among a group of former professional rugby players suing rugby governing bodies for failing to properly warn of the risks associated with repetitive head impacts.
“The finding of death from a neurodegenerative disease being greater in former rugby players than a general population group, based on analysis of hospital and prescription data, despite no data on rugby career length or history of concussion, does again raise the question, why is there a greater risk of brain disease in former rugby players?” says AUT Professor Patria Hume, world leading sports injury biomechanist.
“The evidence that exposure to collision sports is associated with increased rates of morbidity and death from neurodegenerative diseases is continuing to accumulate.”
Dr Helen Murray, research fellow at the Centre for Brain Research at Auckland University, says the findings demonstrate that CTE is not the only risk condition for contact-sport athletes.
“Former contact-sport athletes should be monitored for all types of dementia. Every type of dementia is devastating,” says Murray, a national ice hockey rep. “This study is valuable for us in New Zealand due to the popularity of rugby and other contact sports. The findings of this study emphasise the importance of developing strategies to reduce exposure to head impacts in training and games and to be cautious in our approach to head injury management and return to play.”
The findings come at a pivotal time for Big Sport, on the eve of the 6th International Consensus Conference on Concussion in Sport.
The group, whose consensus statement on concussion has shaped the policies, protocols and attitudes of major sports organisations around the world as regards to the handling of concussion, has been criticised for its watery conclusions to the vexed topic.
A concussion advocacy group, Repercussion, which launched a website this week, has submitted a white paper to the conference.
The group includes well-known names in the neuroscience and brain health field, including New Zealanders Hume, AUT colleague Alice Theadom and Doug King. Also in the group is Stephen Casper, a neuroscience historian whose Twitter account @TheNeuroTimes has often been critical of sport’s reluctance to fully understand and own its occupational risks.
There's a tension at the heart of sport between the war for competitive advantage and the necessity of keeping perspective about risk. Our history shows in global sport, time and time again, that competitive advantage becomes the overwhelming. immediate ethic. Its costs are high.
— Stephen T Casper (@TheNeuroTimes) October 4, 2022
The paper “expresses concern that patient, caregiver, researcher, and provider knowledge like ours remains excluded from a consensus process that has yielded five previous consensus positions on the definition, diagnosis, management, and treatment of concussive injuries. We submit that the consensus process since its inception in 2001 has historically downplayed the detrimental effects of repetitive head impacts in sports.”
It writes that the “wait and see” approach taken by the Consensus Group in the face of mounting evidence of a causal relationship between repetitive head injuries, whether concussive or subconcussive, and neurodegenerative diseases, is no longer fit for purpose.
Its recommendations include:
- Provide guidelines that are patient-first not sport-first;
- Develop criteria to aid clinicians and athletes regarding decisions about retirement from sport;
- Clearly articulate to all stakeholders available evidence for any relationship for a causal link between repetitive head impacts and remote neurodegenerative disease;
- Clearly warn that failure to mitigate repetitive head impact exposures could have repercussions.
The Concussion in Sport Group (CISG) has long been accused of operating for the benefit of Big Sport because so many of its members are paid consultants or advisers to sporting organisations. Repercussion notes that all conflicts of interest should be declared “from the outset and [include explanation as to] how they will be managed”.
CISG is also in the spotlight due to the embarrassment this year of having its chairman Paul McCrory resign following a plagiarism scandal.
McCrory has consulted to many sports, including AFL, and has consistently played down the link between concussion and neurodegenerative diseases, labelling the CTE crisis in the NFL as “hoo-hah”.
He is currently being investigated by Australian health authorities.