Retired rugby players who have suffered multiple concussions have biological differences that may make them more prone to developing motor neurone disease (MND) and other conditions, scientists have said.
Researchers discovered that players who have had five or more concussions during their careers have higher levels of certain proteins in their blood that are linked to conditions including MND and Alzheimer’s disease.
Scientists hope the discovery could one day lead to a “toolkit” to monitor former players.
The study comes after it emerged that former All Blacks player Norm Hewitt died aged 55 with MND.
Leeds Rhinos star Rob Burrow died last month at the age of 41 after a four-and-a-half-year battle with the disease.
The new research set out to examine differences in specific biomarkers between UK-based retired rugby players with a history of concussion and a group of athletes who had not suffered head trauma around seven years after they had retired from sport.
Researchers, led by academics from Durham University, looked for biomarkers in the blood linked to MND, Alzheimer’s disease and chronic traumatic encephalopathy (CTE).
Information on 30 retired male athletes – including both rugby league and rugby union players – who suffered more than five concussions during their careers was compared to data on 26 retired sportsmen who had no history of concussion. All of the sportsmen were taking part in the UK Rugby Health project.
Significantly higher levels of specific proteins called serum t-tau and tau-p181, which play a role in the development of Alzheimer’s and MND, were found in the group who had suffered concussions compared to the healthy control group, according to the study, which has been published in the International Journal of Molecular Sciences.
Rugby players who had been concussed in their career also had lower levels of a so-called retinoid transport protein called RBP-4, which plays a role in the development and functioning of the brain.
Academics said that if blood can be tested and monitored for these specific proteins, it may be possible to diagnose athletes early for neurodegenerative diseases and provide early interventions.
The researchers are trying to secure funding to carry out a follow up study with the players.
Senior author on the study, Professor Paul Chazot, from Durham University’s department of biosciences, said: “The long-term effects of concussions on rugby players, football players, boxers as well as retired military personnel is a major concern, because of the link to neurodegenerative diseases.
“This study gives us the beginnings of a biomarker toolbox to periodically monitor the brain health of retired contact sportspeople, particularly those with a history of concussion during their career.
“It will also pave the way for the introduction of the necessary interventions to minimise the development of future neurodegenerative disease. We have a range of interventions currently in advanced stages of development.”
Co-author, Dr Karen Hind, honorary fellow at the Wolfson Research Institute for Health and Wellbeing at Durham University, initiated the UK Rugby Health study. She added: “This is a crucial development in the field and we’re calling for sustained efforts to define the pathways leading to concussion-induced neurodegenerative diseases.
“Thanks to the research team and all who took part in this important study. Despite the lack of external funding, the UK Rugby Health project continues to make significant contributions to the field.”
Commenting on the study, former Welsh international rugby player Alix Popham, who has been diagnosed with probable chronic traumatic encephalopathy and early onset dementia, called for more to be done to protect rugby players.
Popham, co-founder of charity Head For Change, said: “This is more evidence that big changes need to happen to protect current rugby players.”
Jessica Lee, director of research at My Name’5 Doddie Foundation, added: “The Durham University study has identified potential biomarkers (measurable proteins in blood) elevated in rugby players who suffered concussions.
“These results are preliminary, and the sample size is small, so it’s important to approach results with caution. However, it will be interesting, with further research, to understand if these biomarkers correlate with disease outcomes.
“As part of our Catalysing a Cure research strategy, My Name’5 Doddie Foundation funds numerous research projects with the hope of identifying new targets for future MND treatments – including the investigation of links between sport and MND – and ongoing support from the public in funding this research is essential in our efforts to one day find a cure for this devastating disease.”
Dr Amanda Heslegrave, senior research fellow at UCL’s UKDRI Fluid Biomarker Laboratory, said: “The long-term effects of repeated concussions like those that can be suffered during a sporting career are an area of important research for public health.
“This paper aims to further this research by measuring proteins that are indicative of brain health or injury in blood in retired sportsmen who suffered repeated concussions during their career.
“The sample sizes here are very small – and made smaller when you look at the sub analyses so I do think we need to exercise caution when interpreting results and I would want to see a much bigger study before I would want to draw any conclusions.”
Dr Brian Dickie, from the MND Association, said: “This is a small but intriguing study which raises very pertinent questions about whether there are long-lasting effects associated with repeated concussion, but these preliminary findings will need to be followed up with larger studies in more representative populations.”
