Navigating dietary advice for multiple sclerosis

Abstract Background Multiple sclerosis (MS) is an inflammatory demyelinating disease with no known cure. Numerous diets are promoted to reduce symptoms or even cure MS, despite insufficient evidence for any therapeutic diet. There are few qualitative studies exploring the experiences of people with MS in relation to diet, and no use of theory to explain the findings. Purpose To explore the experiences of adults with MS when navigating dietary advice, their attitudes when making dietary decisions, and their needs regarding dietary resources and education. Methods In this qualitative study, we conducted six focus groups with people with MS (n = 33 plus one spouse without MS). Groups were audio‐recorded and transcribed verbatim. Primary analysis used a general inductive approach with thematic analysis. Secondary analysis aligned themes with the constructs of the self‐determination theory. Results Six themes emerged: (a) confusion about where to seek dietary advice; (b) scepticism towards national dietary guidelines; (c) personalized approaches to dietary change; (d) barriers to dietary changes; (e) judging if dietary changes work; and (f) wanting dietary guidelines for MS. Conclusion People with MS are highly motivated to make dietary changes and improve their health. The self‐determination theory explained why people with MS make dietary modifications, and the varying levels of motivation. MS‐specific dietary resources and nutrition education need to incorporate ways to increase autonomous forms of motivation. Future dietary intervention studies could use the self‐determination theory as a framework to improve long‐term adherence to healthier diets.


| INTRODUC TI ON
Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system with no known cure. 1 Immune-mediated attacks cause inflammation and damage to the myelin sheaths, interrupting nerve signal transmission. 2 Any of the sensory, visual, or motor systems can be affected, causing symptoms that vary widely between individuals and over time. 3 MS affects more than 25 000 Australians, and approximately 2.3 million people worldwide; threequarters of those are female. 3 The most common form of MS is relapsing-remitting MS, where periods of neurological decline are followed by periods of remission. 4 Over time this may progress to secondary progressive MS (half of cases over 10 years 5 ), where deterioration is ongoing. Less common is primary progressive MS (occurring in 10%-15% of cases), where deterioration is from the onset, and there are no remissions. 4 Although diet has been proposed as a potential modifiable risk factor to reduce MS symptom severity and/or slow disability progression, 6 there is insufficient evidence to support any specific therapeutic diets. 7 As such, the dietary advice for people with MS (pwMS) is to follow Government-issued national dietary guidelines. This is to reduce the risk of comorbid diseases (such as cardiovascular disease and type 2 diabetes) and ensure optimum nutritional status. This is imperative, as vascular co-morbidities have been associated with increased disability progression, 8 and some nutrient deficiencies can exacerbate symptoms and accelerate demyelination. 9 The food group and nutrient intake recommendations in the Australian Dietary Guidelines (an example of national dietary guidelines) can be achieved with a range of dietary patterns, including vegetarian, vegan and Mediterranean diets. 10 Unfortunately, less than 4% of Australians achieve these food group and nutrient recommendations. 11 To our knowledge, there is no literature reporting how many pwMS follow national dietary guidelines.
There are numerous non-evidence-based diets promoted online, claiming to reduce MS symptoms, slow MS progression, or cure MS. 12 This creates a challenge for pwMS when deciding what foods to eat, given that the diets are often contradictory 12 and restrictive, that is they don't meet the minimum nutrient requirements outlined in national dietary guidelines. There is an opportunity to provide tailored education to assist pwMS in decision making and meal planning in order to improve dietary intakes. Dietary education programs need to take into account factors such as food preferences, budgets, and food literacy skills. 13 Quantitative studies show that more than 80% of pwMS consider diet to be important, 14 and around 40% report making dietary modifications after their diagnosis. [14][15][16][17] Reducing symptoms or number of relapses, losing weight, having a sense of control, slowing disease progression and curing themselves of MS are common reasons why pwMS make dietary modifications. 14,18 The most common dietary changes described are adopting a low-fat [15][16][17] or low-carbohydrate diet, 17 modifying fatty acid intake, 14 eliminating meat intake, 14 decreasing sugar intake, 16 18 There has been little theoretical explanation as to why pwMS make and adhere to any type of dietary modification. There are very few information provision interventions for pwMS that have been based on theoretical frameworks, 20 despite this being recommended as best practice. 21 Theoretical models are useful for understanding behaviour change and maintenance, and for developing interventions and strategies for behaviour change. 22 One example is the self-determination theory (SDT), which is a theory of human motivation, development, and health, focusing on the types of motivators as predictors of personal and well-being outcomes. 23 In the field of physical activity and MS, the concepts of SDT have been applied to better understand physical activity behaviours and adherence in pwMS. 24,25 Exploring the motivations and barriers for healthy dietary behaviours in pwMS would aid in developing evidence-based dietary resources and interventions for pwMS. These should aim to help pwMS achieve national dietary guideline recommendations, thus reducing the risk of co-morbidities and potentially improving quality of life. 26 The aims of this research were to explore the experiences of adults with MS when navigating dietary advice, their attitudes when making dietary decisions, and their needs regarding dietary resources and education.

| Participants and recruitment
Participants were eligible for inclusion if they were English-speaking adults (age ≥18 years) diagnosed with MS. There were no exclusion criteria. We used purposive sampling to recruit participants from a local MS organization (MS Western Australia [MSWA]) and networks of the project stakeholder advisory group (which included two MS consumer representatives). The study was advertised by MSWA via emails to the member database and social media postings. Potential participants were invited to take part in a single focus group.
Participants were given an AUD$20 department store voucher as remuneration. No participants withdrew from the study after attending a focus group.

| Data collection
We aimed to conduct 5-6 focus groups with 5-8 participants per group. The focus groups were facilitated by RDR (nutritionist, BSc[Hons]), with one of either AB (dietitian, DrPH) or LJB (nutritionist, PhD) as co-facilitators. The topic guide (Table 1) was developed with input from both the relevant literature 18,31,32 and the research team, and the first focus group was used as a pilot group to test the suitability of the questions with participants who had consented.
As a result of piloting, the topic guide was unchanged and therefore the transcripts from the pilot group were included in analysis.
Participants were asked to arrive 30 minutes before the start time to establish rapport with other participants and the researchers, since the researchers did not have existing relationships with the participants. During the focus groups, probing was used to clarify information or seek further details. Demographic information (sex, age, type of MS and duration of MS) and nutrition program preferences (delivery mode, topics of interest, and frequency, duration and number of sessions) were collected using two short questionnaires developed by the research team. To maintain a reflexive stance, 33 the facilitators discussed and made notes after each session to reflect on their assumptions and biases, and how their role as researchers influenced the group discussions. Memos documenting key phrases, states of mind, emotional responses and/or questions to probe in subsequent groups were written after each group. The focus groups were audio-recorded and transcribed verbatim. Transcripts were posted to participants for member checking, 33 confirming that data represented the group discussions. Focus groups were conducted until thematic saturation was reached (ie no new codes emerged). 34

| Analysis
Transcripts were managed with NVivo (version 12.6.0, QSR International Pty Ltd). The first author used a general inductive ap-

| Participants
Thirty-four participants (33 pwMS; one spouse) attended one of six focus groups. The mean number of participants per group was six (range, four to eight). Focus group duration was between 50 and 68 minutes (mean, 60 minutes). The majority of the participants were female (82%), and the mean (SD) age was 50.2 (12.4) years.
The median time since diagnosis was 6 years (range, 0.5-37 years), and the most common type of MS was relapsing-remitting (68%).
See Table 2 for participant characteristics. FG4, 10 years), which is how some restrictive MS diets are promoted.

ACK N OWLED G EM ENTS
This study will partially fulfil the requirements for the degree, Doctor of Philosophy in the School of Public Health, Curtin University, for RDR. We thank the participants and MSWA for assistance in recruiting and use of venues.

CO N FLI C T O F I NTE R E S T
The authors declare no conflicts of interest.

PATI E NT O R PU B LI C CO NTR I B UTI O N
Members of a stakeholder advisory group, which included a neurologist, MS counsellor, MS nurse, psychologist, dietitians and MS consumers, provided input during the development of the question guide and methods for participant recruitment. One MS consumer provided feedback after the pilot focus group session.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from the corresponding author upon reasonable request.