The adherence to Mediterranean diet moderates the association between medical multi-morbidity and depressive symptoms in elderly outpatients

Background Depressive symptoms in the elderly are related to the advancing of age, loss of life purpose, medical multi-morbidity, cognitive decline and social-economic problems mounting evidence suggests that lifestyle behaviors and certain dietary patterns may improve mood and overall well-being in older adults. In the present study we investigated (i) the association of adherence to Med-Diet with depressive symptoms and multi-morbidity in a cohort of geriatric medical outpatients and (ii) the role of Med-Diet in mediating the association between depressive symptoms and multi-morbidity. Methods Morbidity was assessed using the severity index of cumulative illness rating scale for geriatrics (CIRSG-SI). Montreal cognitive assessment (MoCA) and geriatric depression scale (GDS) were administrated to evaluate cognitive and depressive symptoms. Adherence to Med-Diet was evaluated using the Med-Diet 14-Item questionnaire (MDQ). Pearson correlation was used to test association between variables. The Preacher and Hayes’ strategy was used to test the mediational model. Results One hundred and forty-three subjects were included in the study. Significant inverse correlations of MDQ with GDS ( r  = -0.317; P r  = -0.247; P  = 0.003) were found, with and without adjustment for potential confounders. A direct correlation between CIRSG-SI and GDS was also observed ( r  = 0.304; P  = 0.001), with this association being moderated by MDQ ( b  = 0.386; P  = 0.047). Conclusion These findings (i) add to the accumulating evidence that Med-Diet is crucially involved in the regulation of physical and mental health of elderly people, and (ii) suggest that a Mediterranean-style diet may contribute to protect elderly subjects with higher levels of polypathology/multi-morbidity from the development of depressive symptoms.