- Experts from the University of Sheffield conducted three large-scale genetic analyzes
- They looked for a connection between motor neuron disease and exercise.
- Data for the study was obtained from UK Biobank, a DNA and health database
- Team cautioned that exercise does not cause progressive condition
- But it can hasten the onset of disease in people who are genetically predisposed.
One study found that for people with a genetic predisposition to the condition, the risk of motor neurone disease (MND) increased with regular strenuous exercise.
Researchers from the University of Sheffield conducted three large-scale genetic analyzes involving people who practiced different habitual levels of exercise.
They found that exercise alone does not cause MND, but it may hasten the onset of the condition in people with certain genetic profiles.
The findings support previous studies that have suggested the lifetime risk of MND – usually around 1 in 400 – is increased 5–6-fold among professional football players.
In recent years, various high-profile names from British sports have shared their experiences with MND.
These include Rob Burrows and Dodi Weir of rugby and Stephen Darby of football.
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One study found that for people with a genetic predisposition to the condition, the risk of motor neurone disease (MND) increased with regular strenuous exercise. Image: An artist’s impression of motor neurons that progressively fail in patients with MND
In recent years, various high-profile names from British sports have shared their experiences with MND. These include Rob Burrows and Dodi Weir of rugby and Stephen Darby of football. Image: Mr Weir claims the ball at the line-out during the Five Nations International between England and Scotland at Twickenham on February 1, 1997
Also known as amyotrophic lateral sclerosis and Lou Gehrig’s disease, MND is a disorder of the nerves in the brain and spinal cord that talk to the muscles of the body.
As the condition progresses, messages from the brain gradually stop reaching the muscles, which in turn become weak, stiff, and eventually useless.
In this way, MND rapidly affects a person’s ability to walk, talk, manipulate objects, eat, and even breathe. Most patients die within 2–4 years of diagnosis.
Experts have determined that about 10 percent of cases of MND are inherited, but the remainder are caused by complex genetic and environmental interactions.
The researchers hope their findings will help people who are at risk of developing MND make informed decisions about their exercise habits.
About 5,000 people are believed to live with MND in the United Kingdom.
‘Complex diseases such as MND are caused by interactions between genetics and the environment,’ explained Johnathan Cooper-Knock, a neurologist and paper author from the University of Sheffield.
‘We urgently need to understand this interaction in order to discover leading treatments and preventive strategies for this brutal and debilitating disease.
‘We suspected for some time that exercise was a risk factor for MND, but until now this link was considered controversial. This study confirms that repeated strenuous exercise increases the risk of MND in some people.
‘It is important to emphasize that we know that people who exercise vigorously do not develop MND. The sport has a large number of health benefits and most sportsmen and women do not develop MND.
‘The next step is to identify which individuals are particularly at risk of MND if they exercise frequently and intensively; And how much exercise increases that risk.’
In their study, Dr Cooper-Knock and his colleagues used data collected by the UK Biobank, a massive database that contains detailed genetic and health information on nearly half a million participants.
Part of the Biobank study included a questionnaire on physical activity levels – and 350,492 respondents were also asked whether, in the past four weeks, they had spent any time completing one of several forms of exercise.
Possible answers included ‘hard play’, ‘mild DIY’ or ‘heavy DIY’, ‘walking for pleasure’, ‘other exercises’ or ‘none of the above’.
The team divided the subjects into two groups based on whether they had recently spent 15 or more minutes in either strenuous sports or other exercise at least 2 days a week. A total of 124,842 persons met this criterion.
The team also analyzed a dataset of 460,376 participants who had done any type of strenuous exercise or heavy DIY in the past month, as well as exercise-independent movement recorded by an accelerometer study, which involved 91,084 individuals.
Also known as amyotrophic lateral sclerosis and Lou Gehrig’s disease, MND is a disorder of the nerves in the brain and spinal cord (left) that talk to the muscles (center) of the body. As the condition progresses, messages from the brain gradually stop reaching the muscles, which in turn become weak, stiff and eventually clumsy (right)
“This research goes towards uncovering the link between high levels of physical activity and the development of MND in certain genetically at-risk groups,” said paper author and neurologist Dame Pamela Shaw from Sheffield.
‘We studied the link using three different approaches and each indicated that regular strenuous exercise is a risk factor associated with MND.
‘Many of the more than 30 genes known to have MNDs alter expression levels during intense physical exercise.
‘Individuals who have mutations in the C9ORF72 gene – which accounts for 10 percent of MND cases – have an earlier age of disease onset if their lifestyle includes high levels of strenuous physical activity.
‘Most people who do strenuous exercise do not have motor neuron injury and more work is needed to pinpoint the exact genetic risk factors.
‘The ultimate aim is to identify …