What causes MND is the question that so many of us want to know. For the majority of people with MND we know that it is caused by a combination of many environmental, genetic and lifestyle factors, that gradually tip the balance towards someone developing MND. In the very first talk of the 2016 International Symposium on ALS/MND Joel Vermeulen from The Institute of Risk Assessment Sciences at Utrecht University in The Netherlands gave us an update on research underway to understand the environmental and lifestyle contributions to why people develop MND.
What do we know already?
He began by talking about what we know already about environmental exposures linked to MND. So far, there’s only one factor that we definitely know is linked to the cause of MND – and that is that people who have smoked are at a slightly increased risk of developing MND. There are many other factors that have been identified as possible factors MND but the evidence so far is inconclusive. (You can see more about the causes of MND on our website). However, commenting on this he said “the field is moving and I was happy to see so many abstracts at this meeting on this topic”.
Why don’t we know more?
So he asked the question that many of you reading this blog may be asking too – why we don’t know more about what environmental factors are linked to MND? He explained that there are two main reasons for this – the design of the studies and the methods available to conduct this type of research. The design of the studies is hard to change – the number of people who get MND makes it harder to be confident that that results are robust.
Ideally the best way to find risk factors for developing diseases is to look at the health of people over many years, and collect lots of information about them before they get a diagnosis. (This is an approach taken by a long running study of breast cancer in the UK that you may have heard of or even participated in, and a similar rationale to the UK Biobank). As we don’t know who is going to develop MND (and because it is so rare) this is hard to do.
Another approach is to ask people with MND about their environment and lifestyle before they were diagnosed. Although this is a common approach in MND research, it is hard to know if bias is included, or whether things are accurately remembered. While changing the design of studies in this type of research is difficult, improving methods to conduct these studies is more feasible.
How can new research methods tell us more?
Dr Vermeulen spent the last part of his talk explaining some new ways of looking at environmental factors that will allow researchers to understand their contribution to why people get MND. Among these new approaches are what he described as ‘wearables’ – sort of the equivalent of a smartwatch or fitbit to measure exposures or monitor our lifestyle (for example how much exercise we do). He also talked about sophisticated new data analysis methods to look at all our exposures in one go (the ‘exposome’) and finally about looking at clues to exposures left behind on our DNA.
The clues on our DNA are found in a chemical coating of our DNA known as methylation. They are important as the clues are long lasting, unlike the exposure to a contributing factor itself. (It is like the crime squad investigating a case many years after the crime was committed). This means it gets round some of the problems of trying to remember answers to questionnaires about environment and lifestyle that Dr Vermeulen discussed earlier in his talk.
He finished with the offer to explain more about these new methods after the talk and an open offer of collaboration to interested delegates. A comment that illustrates the true spirit of what the International Symposium is all about.
It read with interest what Dr. Vermeulen has to say about ‘What causes MND.
MND had never even crossed my mind or come into my thought processes before I was diagnosed earlier this year. Cancer is in all our lives by knowing someone with the disease or a member of our family. MND is so rare, that most have or will never come into contact with someone who has the disease. This will I’m sure, make finding the cause of MND more challenging.
Hi I’m living with MND and would like to know how I developed this condition. I have never smoked and consider myself fit and healthy before contracting MND cycling 60 miles a week sometimes more
Comments on smoking and MND
Last week we reported on a talk from the MND conference in Dublin, commenting that the only factor that had definitely been linked to developing MND was smoking, and that research into other factors that may have contributed to the cause of MND was inconclusive. It prompted a number of comments on the blog, so I’m writing to try and clarify this.
There are likely to be many, many factors that contribute to why someone develops MND. There is no, one single thing on its own causes someone to get the disease. Researchers have so far found that of those many factors, smoking is the one that we are most certain of. You can read more about the statistics of how these things are worked out in a blog post we published a few years ago: more about the statistics .
My husband & 2 other people I know who had MND have never smoked so I wonder why researchers can say that smoking is the one factor that they are most certain of!!
Thank you for your comment. It is important to know that when we talk about factors that cause MND, we mean that these factors, together with other environmental, lifestyle and genetic ones, can ‘tip the balance’ towards developing MND. We are therefore not saying that smoking, or any other MND-related factor, causes MND on its own. Similarly, even if some factors are more likely to cause MND than others, this does not mean that it will apply to all people equally.
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