Short Oral Presentation Nutrition Society of Australia 50th Annual Scientific Meeting 2026

Associations between fat type and risk of relapse in Australian adults with multiple sclerosis (146844)

Barbara Brayner 1 , Hajar Mazahery 1 , Priscila P Machado 1 , Gavin Abbott 1 , Yun Zhao 2 , Anne-Louise Ponsonby 3 , Valery Fuh-Ngwa 4 , Steve Simpson-Yap 4 , Alice Saul 4 , Ausimmune/AusLong Investigator Group 4 , Bruce Taylor 4 , Lucinda J Black 1
  1. Deakin University, Burwood, VIC, Australia
  2. School of Population health, Curtin University, Perth, WA, Australia
  3. The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC, Australia
  4. Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia

Multiple sclerosis (MS) is a neurodegenerative disease that significantly affects quality of life. Higher saturated fat (SFA) intake has been linked to higher MS activity in some studies, while polyunsaturated fat (PUFA) and monounsaturated fat (MUFA) may exert a protective role.(1) However, there is also evidence to suggest no association between dietary fat and MS progression/activity.(1) A possible reason for this discrepancy is the food source: dietary fats from wholefoods may affect MS progression/activity differently than those from ultra-processed food (UPF); indeed, higher UPF consumption has been linked to higher MS severity(2). We aimed to test associations between dietary fat intake from wholefoods versus UPF and risk of relapse in people with MS. We used data from the AusLong Study, a longitudinal cohort of people with MS. UPF were identified from a food frequency questionnaire (collected at baseline, 5, 10 and 15-year follow ups) according to the Nova system:(3) group 1 includes unprocessed/minimally processed foods (e.g. rice, vegetables, milk); group 2 comprises processed culinary ingredients (e.g. butter, vegetable oil); group 3 includes processed foods (e.g. salted nuts, fish in oil); group 4 comprises UPF, which have undergone a series of industrial processing methods (e.g. sausages, margarine). Categories 1 to 3 were combined and represented the wholefood group. The amount of SFA, PUFA and MUFA as a percentage of energy intake was quantified separately for wholefoods and UPF and used in 1% increments for analyses. Relapses from study entry were confirmed by a neurologist. To test associations with relapse risk, we used covariate-adjusted (age, sex, smoking, study site, alternate Mediterranean diet score as a measure of diet quality, and disease modifying therapy use) multilevel mixed effects parametric survival analyses over 15 years (baseline n=163; 15-year follow-up n=119). Sex interactions and linearity were explored. For wholefoods MUFA only, there was a sex interaction and evidence of a non-linear association with relapse. Higher PUFA intake from wholefoods was significantly associated with lower relapse risk (HRadj: 0.74, 95% CI: 0.65, 0.86, p <0.001). Compared with the lowest tertile, the highest tertile of MUFA from wholefoods was significantly associated with lower relapse risk in females (highest tertile HRadj: 0.64, 95% CI: 0.48, 0.85, p = 0.002). Higher intake of PUFA from UPF was significantly associated with higher relapse risk (HRadj: 1.06, 95% CI: 1.01, 1.13, p = 0.027). These findings suggest that dietary fat affects relapse risk differently depending on the food source (wholefoods versus UPF), highlighting the complexity of nutrition and the importance of understanding different aspects of a diet (e.g., nutrients and foods). These findings contribute to the growing body of evidence on the role of diet in MS, which will ultimately inform the development of dietary guidance for people with MS.

  1. Sand IK (2018) Curr Nutr Rep, 7(3):150-160
  2. Guglielmetti M, Grosso G, Ferraris C et al. (2023) Front Neurol, 14:1086720
  3. Monteiro CA, Cannon G, Levy RB et al. (2019) Public Health Nutr, 22(5):936-941.