Association between Mediterranean Diet and Development of Multiple Sclerosis: A Systematic Review and Meta-Analysis.

Abstract

<h4>Background</h4>Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. Given the conflicting evidence regarding the impact of adherence to the Mediterranean diet (MedDiet) on MS development and the lack of a systematic review on this topic, this study aimed to examine this association.<h4>Methods</h4>Following the PRISMA and JBI methods, a search of electronic databases was conducted through PubMed, Embase, Web of Science, and Scopus up to March 2024. Clinical original studies assessing the association between the MedDiet adherence and MS development were included. Risk of bias was evaluated using JBI critical appraisal tools. Meta-analyses were performed using CMA4 software.<h4>Results</h4>Out of 202 screened records, eight studies, including five case-control and three cohort studies, met the inclusion criteria. Retrospective evidence from three case-control studies suggested that MedDiet adherence is associated with decreased odds of MS, whereas cohort studies showed no significant relationship. Based on the meta-analysis, there was a significant association between high adherence to the MedDiet and reduced odds of MS (fixed-effect OR: 0.275, 95% CI: 0.11-0.72, p-value <0.01, least MedDiet adherence as the reference).<h4>Discussion</h4>Although the meta-analysis showed a significant inverse association between higher adherence to the MedDiet and the odds of MS, the overall body of evidence does not provide strong support for a preventive role of the MedDiet. Considering the limited number of included studies, the predominantly retrospective design, the high risk of bias in several studies, and the substantial observed heterogeneity, further well-designed prospective studies are needed.