Mediterranean Diet Score is Associated with Disability and Brain Atrophy in Multiple Sclerosis
Ilana Katz Sand1, Kathryn Fitzgerald2, Tali Sorets1, Sarah Levy1, James Sumowski1
1Corinne Goldsmith Dickinson Center for Multiple Sclerosis at Mount Sinai, 2Johns Hopkins University
Objective:

To evaluate relationships between Mediterranean diet score and disability in multiple sclerosis (MS)

Background:

The MS community has a high interest in whether diet can act as a disease-modifier. Mediterranean diet score is associated with structural brain metrics and clinical outcomes in cognitive aging, suggesting potential neuroprotection. We have previously noted a relationship between a similar score (MIND, Mediterranean-DASH Intervention for Neurodegenerative Delay) and thalamic volume in early MS. Here we evaluated the relationship between Mediterranean diet score and MS-related disability in a representative clinical MS cohort.

Design/Methods:

Persons with MS (n=500; 70% women; aged 43.8±11.6 years) completed the Mediterranean Diet Adherence Screener (MEDAS) and the Multiple Sclerosis Functional Composite (MSFC) evaluation of cognition, upper extremity coordination, and gait speed. We measured third ventricle width (TVW) on axial T1 images from clinical MRIs as a validated estimate of cerebral atrophy. Multiple regressions investigated the independent contribution of MEDAS to MSFC and TVW controlling for age, sex, race, ethnicity, socioeconomic status, BMI, physical exercise, sleep disturbance, and a cardiovascular risk (CVR) index (hypertension, diabetes, hyperlipidemia, cardiac conditions, smoking).

Results:
Higher MEDAS independently predicted better MSFC (rp=0.200, p<0.001) and lower TVW (less atrophy; rp=-0.122, p=0.007). MEDAS was a much better predictor of both MSFC and TVW than were BMI, exercise, sleep disturbance, or CVR. The link between MEDAS and MSFC was strongest in progressive disease. The relationship between higher MEDAS and better MSFC was partially mediated through lower TVW (rpΔ: 0.200 to 0.167, Ps<0.001), consistent with the notion that MEDAS preserves functional outcomes by supporting brain maintenance. 
Conclusions:

After controlling for important potential confounders, a significant association remains between Mediterranean diet score and MS-related disability. The strength of the relationship in progressive disease and partial mediation by third ventricle width suggests the possibility of a neuroprotective mechanism. Longitudinal studies and interventional clinical trials are needed.