Background: Certain lifestyle factors might influence disease activity in multiple sclerosis (MS).

Objectives: To investigate the consumption of alcoholic beverages, caffeinated drinks, fish and cigarette smoking in relation to disability progression in relapsing onset and progressive onset MS.

Methods: We conducted a cross‐sectional survey amongst individuals with MS, registered by the Flemish MS society in Belgium. A time‐to‐event analysis and Cox proportional‐hazard regression were performed with time to Expanded Disability Status Scale (EDSS) 6 (requiring a cane or support to walk for a distance of 100 m) as outcome measure. Hazard ratios for the time from onset and from birth were adjusted for age at onset, gender and immunomodulatory treatment.

Results: Data of 1372 persons with definite MS were collected. In the relapsing onset group, a decreased risk for reaching EDSS 6 was found in regular consumers of alcohol, wine, coffee and fish compared with those who never consumed these substances. Cigarette smoking was associated with an enhanced risk for reaching EDSS 6. In the progressive onset group, no association with the risk of reaching EDSS 6 was found, except for the type of fish. Preference for fatty fish was associated with an increased risk to reach EDSS 6, when lean fish was taken as the reference category.

Conclusion: Consumption of alcoholic beverages, coffee and fish were inversely associated with progression of disability in relapsing onset MS, but not in progressive onset MS. These findings allow to support the hypothesis that different mechanisms might underlie progression of disability in relapsing and progressive onset MS.