ABSTRACT Objectives Consistency among population-based studies investigating the relationship between diet and cognition in older inhabitants in the Mediterranean area is poor. The present study investigated whether diet changes over 12 years were associated with cognitive function in older people in Southern-Italy. Methods From the ‘Salus in Apulia Study’, that includes the MICOL and GreatAGE Studies, 584 participants were selected, firstly enrolled in MICOL3 (M3) and later in the GreatAGE Study (MICOL4, M4). Foods and micronutrients intake were recorded in both studies, and global cognitive function in M4, assessed with the Mini Mental State Examination. Results Plant-based foods, particularly coffee and vegetables, as well as vitamin A sources, were inversely associated to age-related cognitive impairment. Alcohol consumption showed a detrimental role on cognition, while red meat appeared to be beneficial in the present study, although its role is traditionally considered harmful for cognitive function. Discussion Our study confirmed that a traditional Mediterranean dietary pattern based on agricultural products and low alcohol consumption may help to prevent/delay age-related cognitive impairment.