The Mediterranean Diet (MD) is described in the literature as a beneficial dietary pattern for neurodegenerative diseases such as Multiple Sclerosis (MS). The objective of this study was to evaluate the dietary habits in people with MS (pwMS) and to test whether adherence to the MD could have an impact on the severity of the disease measured as the MS severity score (MSSS). Adherence to the MD was assessed in 31 PwMS using the Mediterranean Diet Adherence Screener (MEDAS), the Pyramid-based Mediterranean Diet Score (PyrMDS) index, and the Italian Mediterranean Index (IMI), and their eating habits were recorded in a food diary for a one-year follow-up. When data obtained from dietary analysis were compared to the MSSS, results showed that pwMS with lower MSSS adhere more to the MD than the other pwMS groups according to the MEDAS index. Furthermore, a high consumption of fiber in the MS mild severity class was observed. Further studies are needed to clarify which of the nutritional components of the MD may impact the course of MS and if the sensitization of pwMS to MD adherence can be a strategy for mitigating the disease.

Multiple Sclerosis (MS) is an autoimmune and neurodegenerative disorder of the central nervous system (CNS), characterized by demyelination, neuronal loss and physical disability. To date, the exact causes of MS remain unknown. Lifestyle factors, in particular diet, have received growing attention due to their impact on human health, their role in modulating disease pathogenesis, and their influence on gut microbiota composition and activity. As a result, numerous studies have been conducted to examine how specific nutrients, and thereby distinct dietary patterns, may affect the onset and progression of MS. In this narrative review, we aim to explore the most recent and updated evidence concerning the role of fatty acids, carbohydrates, proteins and fibers macronutrients in MS development and progression by evaluating the most relevant literature findings from preclinical models, and clinical trials on people with MS. Dietary macronutrients influence MS pathology through immune and gut–brain axis modulation. Diets rich in saturated fats and refined carbohydrates exacerbate neuroinflammation, promote Th1/Th17 polarization, and worsen disease severity. Conversely, monounsaturated and omega-3 polyunsaturated fatty acids, dietary fibers, and adequate tryptophan metabolism exert anti-inflammatory effects, enhance regulatory T cell (Treg) activity, and improve clinical outcomes. Fiber-derived short-chain fatty acids (SCFAs) and omega-3 metabolites also support gut barrier integrity and suppress astrocyte activation. Evidence on dairy, meat and gluten remains inconclusive, though certain milk proteins and certain components of red/processed meat and of wheat may promote inflammation. Overall, anti-inflammatory and fiber-rich diets, such as those emphasizing unsaturated fats and low sugar intake, appear to confer protective effects in MS. The clarification of the role of dietary components in relation to the disease could help to guide patients toward a healthy and balanced diet, with positive effects on their overall health.