Multiple sclerosis (MS) is a chronic immune-mediated neurodegenerative disease that affects the central nervous system (CNS). The exact pathophysiology of MS remains unclear; it is suggested that the inflammatory state persists under a genetic-energetic-environmental complex causing a variety of clinical symptoms depending on the neuroanatomical location of MS lesions. The age of MS onset ranges between 20 and 40 years. MS is usually initiated as a relapsing-remitting disease, which may last several years to decades affecting females twice as often as males. Dietary factors may have an important impact on MS. Data from human and animal studies indicate that saturated fatty acids (SFA), the major fat type of animal foods in the "Western" diet, increase MS susceptibility. The Mediterranean dietary (MedDiet) pattern is hypothesized to be beneficial to MS patients protecting against the development cardiovascular diseases. However, little is known about the cardiovascular effects of the MedDiet on MS patients. Consequently, the aim of the present randomized, case control study was to investigate the effects of MedDiet on cardiovascular factors in women with relapsing-remitting MS after a 3-month intervention period.

• Adult women with MS, who were outpatients of Iaso Hospital (Athens, Greece), were enrolled in the present study. Detailed information was provided using a leaflet, in which aims and methodology were described before recruitment. All participants fulfilled informed consent and kept a signed copy. Before the start of the trial, the Ethics Committee of Iaso Hospital (Athens, Greece) assessed and approved the protocol of the study (Approval Code #E31052019). The study was performed according to principles of the Helsinki Declaration (1964) and terms of Good Clinical Practice.
• The study took place during the winter season. All patients were recruited at the first week of December 2020 and the intervention lasted 3 months.
• Study design: 3-month randomized, single center case control study; maintenance of the blind-to-treatment allocation was performed in order to avoid bias; in the intervention group, MS women received a personalized daily eating plan generated by a Clinical Decision Support System (CDSS) together with nutritional consultation on the Meditteranean dietary pattern, as well as physical activity guidelines; patients of the control group received general dietary advice and physical activity recommendation that was in accordance with the "National Dietary Guidelines for Greek adults";
• Screening: medical history; nutritional history (food frequency questionnaire, MedDietScore, 24-hr recalls); anthropometrics; depression and anxiety (Hospital Anxiety and Depression Scale); blood biomarkers (glucose, lipids, C-reactive protein).

Inclusion Criteria: adult women (≥ 18 years) with relapsing-remitting MS diagnosis; patients should follow a standardized immunomodulatory therapy or other disease-modifying therapy for at least 6 months; the patient should be able to walk without aid or work a full day in a position of average difficulty, as indicated by scores of Expanded Disability Status Scale (EDSS) < 4.5; patients with at least one lesion on brain MRI and/or at least one relapse in the past two years.

Exclusion Criteria: women with concomitant illness (e.g. malignancy, infections, malabsorption, heart-, liver- or renal failure); patients who changed treatment during or ≤ 6 months before the start or the trial; psychiatric conditions, alcoholism, drug addiction; using vitamin or mineral supplements during or ≤ 6 months prior to screening; following a vegan diet ≤ 5 years prior to screening or using weight loss medications; pregnant or lactating women.

• All patients were randomly assigned to either the control or the intervention group, using single randomization. An independent researcher applied a computerized sequence to generate the randomization list. Next, the principal investigator who was responsible for the completion of each participant's form recorded the patient trial number in a sealed envelope. Maintenance of the blind-to-treatment allocation was performed in order to avoid bias. Treatment data were exposed to the analyst only after assessing outcomes. During the 3-month intervention, dietitians performed regular phone interviews on a 15-day basis to assist nutritional and lifestyle consultation in both groups.
• All patients were instructed to keep (a) weekly food diaries (2 weekdays and 1 weekend day) and (b) 24-hour dietary records, which all were assessed remotely via emails and unexpected phone calls.