Introduction: Growing evidence supports the role of healthy dietary patterns, such as the Mediterranean diet (MED), in preserving cognitive function during aging. Characterized by a high intake of fruits, vegetables, legumes, whole grains, fish, and olive oil, and a low consumption of red meat and processed foods, the MED diet may offer neuroprotective benefits. However, longitudinal data examining this association in community-dwelling older adults remain limited. This study aimed to explore both cross-sectional and longitudinal associations between adherence to the MED diet and cognitive performance in a large sample of older adults.

Methods: Data were drawn from the TOLEDO Study of Ageing, involving 963 community-dwelling older adults, without mobility limitations or dementia. Adherence to the MED diet was assessed using the PREDIMED questionnaire. Cognitive performance was evaluated at baseline and after 3 years through a comprehensive neuropsychological battery includingthe Mini-Mental State Examination, Short and Long-Term Memory Recalling Test, Boston Naming Test, Verbal Fluency Test, Digit Span Forward, Go/No-go Test, Edinburgh Handedness Inventory, Luria Orders Test, Clock Drawing Test, and Serial Word Learning Test.

Results: Cross-sectionally, higher adherence to the MED diet was significantly associated with better performance on tests of executive function (e.g., Luria), attention/working memory (Digit Span), and cognitive laterality (Edinburgh Handedness Inventory). Longitudinally, these associations remained significant. Additionally, a positive association with delayed free recall performance (short-term memory) emerged over time

Conclusion: Greater adherence to the MED diet is associated with better cognitive performance, particularly in executive, attentional, and memory domains, both cross-sectionally and over time. These findings underscore the cognitive benefits of the MED diet in aging populations.