MNDF response to links between rugby and MND

Over the last couple of weeks, many of you may have seen articles in the press and on social media claiming that rugby can cause MND. My Name’5 Doddie Foundation would like to clarify a few points regarding this.

Much of this coverage, while well-intentioned, may have missed or not made clear, key points regarding existing studies and data, leading to inaccurate headlines and stories which may have caused alarm.

MND research is complex, and this is no exception. Therefore, in typical straight-talking Doddie fashion, we’d like to give you some clarity on the research landscape involving rugby and MND to date, along with what we’re doing to better understand any potential connections. 

Small Studies and Unreliable Data:

Some published studies have suggested that there’s a correlation between playing elite-level rugby and a higher likelihood of developing MND. Because MND is an uncommon disease, one downfall of these studies to date has been small sample sizes, meaning that the data is not very reliable. 

Following the release of a 2022 study linking elite-level Scottish rugby to MND, we issued a statement welcoming the research, but urging caution when drawing conclusions from the data due to the very small number of people with MND in the study. We called for further investigation into this potential link in the form of larger studies.

Correlation Doesn’t Always Mean Causation:

These studies have also not provided evidence of causation (i.e. that it’s specifically rugby causing MND). Therefore, if there is a correlation between playing elite-level rugby and developing MND, it could be caused by other factors associated with, but not exclusive to rugby. We will explore some of these other factors in more detail below: 

Head Trauma: 

One suggested link between rugby and MND is the head trauma that some rugby players experience over the course of their career. The connection between head trauma and dementia (particularly chronic traumatic encephalopathy dementia) is well-documented – however MND is a separate disease and currently there is no robust evidence to suggest that head trauma also causes MND.

That said, My Name’5 Doddie Foundation (alongside MND Association and MND Scotland) are funding a further large-scale study in this field to generate better quality data to more accurately explore and understand the potential link between head trauma and MND.

Rugby is not the only elite sport that has been linked to higher rates of MND diagnosis versus that of the general public. Various sports, from football to long distance cross-country skiing have also been linked to MND. While football sees regular head impacts from headers, long distance cross-country skiing is not a sport associated with head trauma, which raises questions regarding the connection between head trauma and MND. As an example, outside of sport, older studies have indicated that military veterans, who are unlikely to suffer regular head trauma, are also more likely to develop MND than non-veterans. 

Strenuous Exercise: 

A suggested connection between MND and certain elite-level sports is whether strenuous physical exercise could be linked to the development of MND in people with a specific gene mutation. My Name’5 Doddie Foundation is supporting a study at the Sheffield Institute of Translational Neuroscience which is investigating this potential link further.

It is important to note that there is no evidence that taking part in exercise alone increases the risk of developing MND and the vast majority of people who take part in strenuous exercise will not go on to develop MND. In general, the benefits of taking part in exercise far outweigh any potential risk associated with developing the disease. 

If you’re interested in hearing more on the subject, Professor Kevin Talbot spoke with our patron, Jill Douglas, and Head of Medical Affairs, Sean McGrath, on the topic during an Ask the Expert session on ‘Identifying the Causes of MND’. This link will take you to the stage of the interview where sports and strenuous physical exercise are discussed.

In Conclusion:

While small-scale existing studies have suggested a correlation between MND and elite-level rugby, the data should be treated with caution as small sample sizes can lead to unreliable results and therefore larger scale studies need to be conducted to investigate the links further.

The risk of developing MND depends on a number of things including genetics, ageing and other factors we’re still figuring out. While we appreciate that it may sound alarming to read about potential connections between MND and strenuous physical exercise, please remember that the benefits of exercising vastly outweigh any potential risk of developing the disease. 

Everyone should enjoy their exercise and we’d like to remind you that there’s no evidence that taking part in exercise alone is enough to increase the risk of developing MND. Even with strenuous physical exercise (e.g. professional athletes, veterans), the great majority of people who take part in this will not develop MND.

My Name’5 Doddie Foundation is committed to funding research to unravel any potential links between sport, rugby, exercise and MND and we will always have the MND community at the heart of everything we do. We will continue to share information with our community and make it as understandable, accessible and relevant as possible. Thank you to our supporters for continuing to make this vital research possible, none of this would be possible without your incredible efforts.