- AusImmune and AusLong researchers followed people annually for 10 years after their first episode of demyelination (the first attack of MS) and measured several key factors over this long period.
- This study assessed the quality of dietary intake in the preceding 12 months and compared this against depression, anxiety and fatigue scores at the five- and 10-year mark after the first demyelination event.
- There were mixed results, but researchers found some evidence that a higher diet quality was associated with a lower level of depression and anxiety, but no evidence that diet quality was associated with levels of fatigue.
The AusImmune and AusLong studies have been some of Australia’s longest-running research projects and continue to provide important long-term outcomes following the first episode of demyelination (the first attack of MS).
This particular study, published in the journal Multiple Sclerosis and Related Disorders, involved researchers from several disciplines (dietetics and nutrition, neurology, epigenetics, epidemiology) working together and was led by MS Australia-funded researcher Dr Alice Saul.
What did the researchers aim to do that was different?
At present, there is insufficient evidence to suggest that dietary interventions change the course of MS.
Rather than focusing on specific food groups, individual foods, or nutrients like many other research studies have done, this study used tools to assess the overall quality of the diet.
Specifically, two different measurements were used, the Australian Recommended Food Score (ARFS) and the Diet Quality Tracker (DQT), which have not been used in MS research.
In other chronic health diseases such as cardiovascular disease and diabetes, using these types of diet quality assessments has helped establish that higher diet quality scores are associated with a lower risk of disease.
In this study, researchers aimed to see if diet quality had any link to three common and challenging MS symptoms; depression, anxiety and fatigue.
A total of 190 participants were assessed at two time points after their first demyelinating event; first at five years and then again at 10 years.
Their diet quality in the preceding 12 months to each of these visits was compared to their scores for depression, anxiety and fatigue.
Participants who did not progress to MS after the first demyelinating event were excluded from the analysis.
What is high diet quality?
A high diet quality is recognised to be rich in vegetables, fruit, fish, vitamin C, vitamin E and antioxidants. These components have also been shown to have positive effects on mental health.
The expectation for this study was that a higher diet quality would be associated with lower levels of depression, anxiety and fatigue in people after their first demyelinating event.
What did the results show?
All 190 participants who were analysed in this study went on to develop clinically definite MS in the 10-year follow-up period (that is, they had subsequent demyelinating events to classify them as having MS).
However, there were mixed results from the study. There was some evidence that a higher diet quality in the 12 months prior to the five- and 10-year assessments was associated with lower levels of depression and anxiety, but it was a modest improvement.
Additionally, there was a lack of consistency between the two diet quality measurement tools, with the ARFS showing lower levels of depression, but no clear dose response (i.e. adding more high-quality foods did not result in lower depression scores).
Furthermore, there was no convincing evidence that diet quality was associated with levels of fatigue.
What diet is recommended for people with MS?
At present, there is insufficient evidence to suggest that dietary interventions change the course of MS, and the current lifestyle advice remains for people living with MS to follow the Australian Dietary Guidelines.
The study researchers suggest that rather than focusing on individual food groups, foods, or nutrients, the use of a broader diet assessment tools such as those used in this study may be an alternative to explore diet and MS outcomes in the future.
It is clear that more work needs to be undertaken in the field of diet, nutrition and MS to better understand potential links with MS symptoms and what is ideal for the best health outcomes. This will be the focus of ongoing research in the coming years.