EvaluatingtheEffectsofDietaryInterventionson DiseaseProgressionandSymptomsofAdultswith MultipleSclerosis:AnUmbrellaReview

Abstract

Multiple sclerosis(MS) is a chronic inflammatory autoimmunedisease of the central nervous system. The role of diet in the progressionof MS and severityofsymptomsremainsunclear.Varioussystematicliteraturereviews(SRs)havereportedtheeffectsofsinglenutrientsonMSprogressionor the role of dietary factors on specific symptoms of MS. Narrative reviews have examined the effects of various dietary patterns in MS populations. An umbrella review was undertaken to collate the findings from review articles and evaluate the strength of the scientific evidence of dietary interventions for people living with MS. Scientific databases including MEDLINE, PubMed, CINAHL, and The Cochrane Library were systematically searched up to April 2019. Review articles and meta-analyses were included if they examined the effect of any dietary intervention in adult populationswithMS.OutcomesincludedMSprogressionindicatedbyrelapses,disability,MRIactivityanddiseaseclassification,andMSsymptoms. Characteristicsandfindingsfrombothreviewarticlesandtheirincludedprimarystudieswereextractedandsummarized.Atotalof19SRsand43 narrativereviewswereincluded.VitaminDandPUFAswerethemostcommonlystudiedinterventions.AcrossSRstudies,vitaminDsupplementation had no significant effect on relapses, MRI, or disability progression; however, an inverse association was found between vitamin D status and disability scores through observational studies. Effects of PUFA supplementation on major outcomes of MS progression were inconsistent across review articles. Other interventions less commonly studied included vitamin, mineral, and herbal supplementation and varying dietary patterns. Strong consistent evidence is lacking for dietary interventions in persons with MS. The body of evidence is primarily focused around the isolation ofindividualnutrients,manyofwhichdemonstratenoeffectonmajoroutcomesofMSprogression.Strongerfood-focusedstudiesarerequiredto strengthentheevidence