Diets Similar to the Mediterranean Diet Are Associated with Lower Depression Scores and Improved Cognition Scores in People with Multiple Sclerosis

Background: Depression, fatigue and cognitive impairment are debilitating symptoms common in people with multiple sclerosis (PwMS) that adversely affect quality of life. In the general population, adherence to a Mediterranean-style diet correlates with improvements to mood, fatigue and cognitive impairment. Whether a similar association exists in PwMS is unknown. 

Objectives: To assess the association between adherence to a Mediterranean-style diet and self-reported depression, fatigue and cognitive impairment. 

Methods: Thirty-four PwMS completed a 24-hour dietary recall. Responses were used to quantify adherence to a Mediterranean-style diet using a well-validated scoring approach that incorporates high intakes of fruits, vegetables, whole grains, seafood, polyunsaturated fat, and nuts/legumes, and low intakes of red and processed meats, and moderate alcohol consumption. Individuals with >median intake of each specified food group received 1-point; scores for red and processed meats (where lower intakes are desired) were reversed, and individuals with moderate alcohol consumption (defined as >5g and <15g per day) also received 1-point. We summed individual food-group points to obtain an overall Mediterranean diet score (aMed), ranging from 0 (poor diet quality) to 8 (high diet quality). Participants provided information on depression, fatigue and cognitive impairment symptoms by completing Neuro–Quality of Life (Neuro-QoL) subscales. We assessed the association between aMed scores and Neuro-QoL subscales using spearman correlations and linear regression models adjusted for age and sex. 

Results: Thirty-four PwMS (average age [standard deviation]: 44.6 [11.6]; 67% female) completed dietary recalls and Neuro-QoL subscales for depression, fatigue and cognitive impairment. Higher aMed were associated with less severe depressive and cognitive impairment symptoms (for depression: r=0.42, P=0.01; for cognitive impairment: r=0.41; P=0.02). Individuals in the top tertile of aMed scores reported significantly lower average depressive symptoms relative to those in the bottom tertile (mean difference=4.1; 95% CI: 0.17-8.03). aMed scores were not associated with fatigue severity. 

Conclusions: This cross-sectional survey suggests that adherence to a Mediterranean-style diet may be associated with less severe depressive and cognitive impairment symptoms in PwMS. Interventional studies are needed determine the directionality of this relationship.