Does playing contact sports increase motor neurone disease chances?
There are many examples of footy players diagnosed with motor neurone disease, including Carl Webb this week. Which begs the question: what’s the link between the two, asks Dr Shyuan Ngo.
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On Wednesday came the news that former National Rugby League player Carl Webb had been diagnosed with early-onset motor neurone disease (MND).
Also known as amyotrophic lateral sclerosis (ALS) or Lou Gehrig’s disease, this disorder is an incurable neurological condition. It occurs when neurons in the brain and spinal cord degenerate, progressively paralysing the muscles that allow us to eat, walk, swallow and more.
There is no cure, and there is no effective treatment. The average life expectancy of a person with MND is 27 months – not even Two-and-a-half years – after diagnosis.
Webb is 38, and this is now his reality.
On average, two people are diagnosed with MND every day in Australia. Webb’s diagnosis made headlines because he is a well-known sporting figure. He represented Queensland in State of Origin, and played for club sides North Queensland Cowboys, the Brisbane Broncos and Parramatta Eels.
But he is not the only footballer to be diagnosed with this debilitating and ultimately fatal disease. Neale Daniher, a former AFL player and coach, has been living with MND for more than six years. There are many other examples, both here in Australia and overseas, of rugby league, rugby union and soccer players who have been diagnosed, and in some cases passed away, from MND.
Is this a pattern? Are footballers, and other people playing high-contact sports, more susceptible to developing MND, or do they just receive more publicity because of their prominence?
In 2018, a study published in the Journal of Neurology, Neurosurgery & Psychiatry that looked at the lifestyles of 1,557 adults diagnosed with MND in Ireland, Italy, and The Netherlands, reported that physical activity, in itself, was linked to an increased risk of MND. In the study, physical activity was measured using “Metabolic Equivalent of Task (MET) minutes”, which essentially equates to how much energy a person uses relative to their mass when doing physical activity, and relative to a set reference value of energy that is used when sitting quietly.
More recently, a 2019 review published in Global Spine Journal of 16 scientific studies found two factors that increased an athlete’s chance of developing MND. One was playing their sport professionally, and the other was being involved in a sport “prone to repetitive concussive head and cervical spinal trauma”. These two factors have an additive effect, that resulted in professional athletes involved in sports with a high risk of concussion or spinal injury even more at risk of developing MND.
But, it is more than just concussive head and cervical spinal trauma from sports. In a study using Danish national registries, it was found that any trauma requiring hospitalisation was linked to increased risk for MND.
Physical activity is important for our general health and wellbeing. It protects us from a number of common diseases, including heart disease and diabetes. So, we need to remember that what we are talking about here, is risk. An increase in risk does not mean that physical activity or playing sports at a professional level is necessarily the cause for MND.
MND is a complex disease with no single known cause. The current view in the field is that a person’s genetics and environmental exposures need to come together in a specific combination in order for MND to be triggered. This is most commonly referred to as the multistep hypothesis, where genetic make-up is the first step, and lifetime exposures make up the other steps.
What are the genes and/or combination of genes that cause MND? What are the other steps; is it maybe physical trauma, or something in our environment? To answer these questions, we need to do more research.
Researchers across Australia and the world are racing against time, looking for answers to unlock this disease. Researchers are working to discover what goes wrong and what causes neurons to die, so that they can develop treatments to stop the disease in its tracks. The number of clinical trials for MND is increasing.
It is not a matter of if we will find a treatment for MND. It is a matter of when. We all have hope that the “when” will be soon.
Dr Shyuan Ngo, Scott Sullivan MND Research Fellow at the Queensland Brain Institute and Group Leader at the Australian Institute for Bioengineering and Nanotechnology, The University of Queensland
Pine Rivers Rotary Club and MND & Me Foundation are holding a charity golf day to raise funds for the Queensland Brain Institute. To register or find out more, visit this website.
Originally published as Does playing contact sports increase motor neurone disease chances?