Is there an effect of dietary intake on MS-related fatigue? - A systematic literature review.

Background: Fatigue is considered the most common symptom of persons with multiple sclerosis MS (pwMS), occurring in up to 90% of the patients at some point with two-thirds of pwMS experience fatigue as their most disturbing symptom. Pharmacological treatment options for MS-related fatigue show only limited and contradicting results. Consequently, many pwMS search for alternative options to control the symptom. A considerable interest in dietary interventions as a means of MS symptom management has advanced in the MS community. Yet, the few empirical studies focussing on the effect of holistic dietary intake on fatigue have not been systematically examined. The aim of this review was to systematically review the effect of holistic dietary intake and the subjective perception of fatigue in adult pwMS.

Methods: Embase, Medline, Web of Science, CINAHL Complete, SPORTDiscus, PsycInfo, and Rehabilitation and Sports Medicine (Ebsco Host) databases were systematically searched to locate relevant literature. Intervention trials studying the effect of a holistic dietary regimen on the subjective perception of fatigue in a sample of adult pwMS were considered for inclusion. Risk of bias was assessed using a modified Downs and Black checklist.

Results: A total of four studies met the inclusion criteria: one single arm intervention pilot trial, one randomised controlled pilot trial, one double-blinded randomised trial, and one assessor-blinded randomised controlled trial. Interventions were low fat diets, a low fat, starchy plant food diet, and modified paleo diets and ranged from three to 12 months duration. Two studies supplying an adequate amount of folate and magnesium with the intervention diet reported relevant improvements in fatigue scores.

Conclusion: Dietary intake holds the potential to lower MS-related fatigue, but solid conclusions are not possible based on the existing evidence. Sparse evidence points towards an effect of adequate magnesium and folate intake and a trend for decreased fatigue.