- Florey research has found a potential link between a Mediterranean-style diet and a lower risk of MS onset, with a key epigenetic process playing a partial mediating role.
- Multiple sclerosis (MS) is a complex autoimmune disease driven by genetic and environmental factors.
- While previous studies have suggested diet is implicated in MS risk, how diet influences this risk remains unclear.
Florey researchers have uncovered new insights into how diet might influence the biological pathway involved in the development of MS, a chronic disease in which the immune system attacks the brain and spinal cord.
Diet intake has been linked to MS onset risk, but the mechanism that influences this link is unclear.
In this study, researchers investigated whether differences in DNA methylation — a biological process that helps control whether genes are turned on — could help explain part of the link between diet and MS risk. They also studied whether these diet–MS relationships were different in people with key MS-related genetic risk variants.
Using data collected from more than 500 participants in the Australian Ausimmune Study, the research showed up to one third of the association between consuming a Mediterranean-style diet and lower MS onset risk was in fact mediated by differential DNA methylation.
While DNA methylation can also be influenced by genetic variation, it is potently affected by our cumulative and short-term environmental exposures and lifestyle behaviours, including diet.
The study also found that the relationship between a Mediterranean-style diet and a lower risk of MS onset appeared to apply even in people who carried common genetic risk variants for MS.
The researchers conducted two separate measures.
Firstly, participants completed a comprehensive assessment of their typical dietary intake, from which researchers scored how well participants’ diets aligned with a Mediterranean-style diet. Then, from blood samples collected at the same time, researchers measured DNA methylation.
With these two measures, they could evaluate the associations of Mediterranean-style diet with MS risk and how much of this association acted via differences in DNA methylation in particular sets of genes.
Lead researcher and Florey PhD student, Mehari Merid, said the findings provide valuable insights into how diet may be acting upon MS onset risk.
“Although this study does not provide new information for people to change their diets to manage the course of MS, it does emphasise the role of nutrition,” Mr Mehari said.
“Our work is important in understanding how diet and other risk factors may affect MS and inform future prevention and treatment strategies.”
Co-supervisor, Professor Anne-Louise Ponsonby, who heads The Florey’s Neuroepidemiology Research Group, said diet is an important area of study in MS.
“If we understand how an apparent beneficial effect acts through epigenetic programming — switching a set of genes on or off — then we may be able to understand causes of MS onset better,” Professor Ponsonby said.
“This contributes to the emerging field of nutritional epigenetics by providing a better understanding of the underlying biological mechanism of how Mediterranean-style diets may influence MS risk onset.
“However, people with MS should continue to follow advice from their doctor and neurologist, alongside national dietary guidelines, when making dietary choices.”
The researchers are grateful to the Ausimmune Study participants and funders of this project, including the Multiple Sclerosis Australia, the National Health and Medical Research Council (NHRMC) and the USA’s National Multiple Sclerosis Society.
The findings have been published in the journal Multiple Sclerosis.
