Examining the Moderating Role of a Mediterranean Diet in the Relationship Between Perceived Stress and Cognitive Function in Older Adults

Objectives: Perceived stress and adherence to a Mediterranean diet pattern have been identified as independent predictors of cognitive function in older adulthood; however, no studies to date have examined the interaction between perceived stress and diet adherence on cognitive health. This cross-sectional study investigated the synergistic effect of perceived stress and adherence to a Mediterranean diet pattern on cognitive function in 192 nondemented older adults aged 60-95 years. Method: Participants completed a Food Frequency Questionnaire (FFQ) and the Perceived Stress Scale (PSS-10). Executive functioning was assessed using the Trail Making Test-Part B (TMT-B) and episodic memory was assessed using the immediate and delayed free recall subscales from the California Verbal Learning Test (CVLT-II). Results: Moderation analyses revealed that higher perceived stress was associated with worse executive functioning at low levels of Mediterranean diet adherence (B = 1.75, SE = 0.67, p = .009), but not at moderate and high levels of Mediterranean diet adherence (ps > .05). Perceived stress was not associated with episodic memory, irrespective of Mediterranean diet adherence. Discussion: Findings provide preliminary evidence that the association between higher perceived stress and poorer executive function may be dependent on diet intake. Additional research is needed to confirm these findings.