Vigorous exercise may be linked to a heightened risk of developing motor neurone disease, a new study suggests.
The disease, also called amyotrophic lateral sclerosis, or ALS, is sometimes known as the ‘Athlete’s curse’ because it affects a disproportionate number of sports people.
ALS, which impacts two in 100,000 people in Britain, is a progressive, fatal neurodegenerative disease for which there is currently no treatment. Last month Stephen Hawking, the theoretical physicist, died from a rare version of the condition.
To try and find out what might cause the illness, researchers compared the lifestyles of 1,557 ALS patients in Europe with 2,922 healthy people.
They discovered that people with ALS were more likely to have engaged in intensive exercise. People who exercised the most were 26 per cent more likely to develop than those were were the least active.
“We observed a linear association, which means that the risk appeared to increase with each increase in exercise level,” said lead author Professor Leonard van den Berg, from the Department of Neurology, atUniversity Medical Center, Utrecht, The Netherlands.
“Overall, physical activity has been demonstrated to be protective against many diseases, including cardiovascular disease, diabetes, and a variety of cancers.
“Decreasing the risk of these common conditions may be a trade-off with increasing the risk of a relatively rare disease such as ALS.”
The researchers concluded that while exercise is not likely to be a major factor in the development of ALS, this level of increased risk might be important in those who are genetically predisposed.
Commenting on the study, British experts said it was important to balance out the potential danger of vigorous activity with evidence that regular exercise protects against a range of conditions.
Prof Tara Spires-Jones, Deputy Director of the Centre for Discovery Brain Sciences at the University of Edinburgh, said: “This study is important as it is part of a large effort to understand the causes of ALS in order to develop effective treatments and preventions for this devastating disease.
“It is important to keep in mind that ALS is a relatively rare disease affecting around 2 in every 100,000 people and that physical activity protects us from much more common diseases including Alzheimer’s, heart disease, diabetes and cancer, which together affect more than 10 million people in the UK today.”
Dr Jemeen Sreedharan, van Geest Postdoctoral Fellow in Neurodegeneration, Institute of Psychiatry, Psychology & Neuroscience at King’s College London, added: “The overall benefits of exercise to general physical and mental health probably outweigh any increased risk of ALS due to physical activity.”
Nick Cole, Head of Research at the Motor Neurone Disease Associationadded: “Put in context, it is a small increased risk and one of multiple factors, from genetic to environmental, likely to be needed in a combination to develop MND.
“Given that exercise has been shown to offer significant protection against many diseases it would not be advisable to adopt a sedentary lifestyle in order to avoid a very small increased risk of developing MND.”
The research published online in the Journal of Neurology Neurosurgery & Psychiatry.