The Couch Potato Enigma: Unraveling the Mystery of Motor Neurone Disease
Have you ever wondered why some people, despite leading active lives, still fall victim to Motor Neurone Disease (MND)? Professor Dame Pamela Shaw, a renowned neurologist, has been studying this very question for years, and her findings might just surprise you.
"I've encountered thousands of MND patients, and an intriguing pattern emerged: almost none of them led a sedentary lifestyle. In fact, many were professional athletes or highly active individuals. This observation has sparked my curiosity, and I'm determined to uncover the reasons behind it," says Professor Shaw.
But here's where it gets controversial... Professor Shaw and her team at the Sheffield Institute for Translational Neuroscience (SITraN) believe that it's not just about being active; it's about the interplay between an individual's genetic makeup and their lifestyle choices.
"We think it's a delicate balance. While most athletes don't develop MND, those with a specific genetic predisposition, particularly a mutation in the C9orf72 gene (known as the C9 gene), might be at a higher risk if they engage in strenuous exercise," she explains.
To support this theory, Professor Shaw and her colleague, Professor Johnathan Cooper Knock, have made significant strides in understanding the disease's causes. They discovered that individuals with the C9 gene mutation who engage in intense physical activity are more likely to develop MND at an earlier age.
"Imagine having the genetic makeup that predisposes you to MND. If you lead a sedentary life, your motor neurons might remain undamaged. However, if you're an athlete or a marathon runner with the same genetic makeup, you're putting stress on your motor system. If your body's stress response isn't robust enough, over time, this could lead to the gradual deterioration of motor neurons," Professor Shaw elaborates.
And this is the part most people miss... Professor Shaw shares a compelling case study of identical twins, both with the C9orf72 gene change. One twin, an avid gym-goer and triathlete, developed MND in his 30s and passed away. His twin brother, on the other hand, led a sedentary life with no exercise and remained unaffected 12 years later.
At SITraN, Professor Shaw and her team have conducted innovative experiments with fruit flies, further supporting their theory. "We've found that exercise interacts with their genetic makeup too. When we force fruit flies with the human C9 gene to exercise vigorously, their lifespan, motor strength, and climbing speed decrease, which is the opposite of what happens with healthy exercise in humans," she explains.
Professor Shaw's theories have also been corroborated by studies in other countries. For instance, a study in Sweden found that elite cross-country skiers who competed in the Vasaloppet race multiple times had a significantly increased risk of developing MND compared to those who trained and participated only once.
Another intriguing study from the American military showed a four-fold increase in the risk of developing motor neurone disease (known as ALS in the US) among military personnel. Professor Shaw believes this presents an opportunity to delve deeper into the genetic and environmental factors contributing to this risk.
"I suspect it's linked to the heavy physical training they undergo," she says.
However, Professor Shaw is quick to clarify that their research doesn't discourage healthy exercise. "We don't want to deter people from engaging in protective physical activities. It's not just about going for a gentle run; it's about pushing your body to its limits," she emphasizes.
The path to finding a cure for MND or alleviating its devastating symptoms lies in understanding its causes, and Professor Shaw and her colleagues at SITraN are making remarkable progress in this field.
So, what do you think? Is there a delicate balance between genetics and lifestyle choices when it comes to MND? Share your thoughts and let's spark a conversation in the comments below!
