Background Current evidence suggests that nutrition in general and specific dietary patterns in particular, such as the Mediterranean type diet (MeDi), can be employed as potential preventive strategies against the development of dementia and cognitive decline. However, longitudinal data exploring the applicability of these findings in populations of Mediterranean origin are limited. The aim of the present study was to explore the potential relationships of MeDi adherence with dementia incidence rates and cognitive change over time in a traditional Mediterranean population, characterized by a lifelong exposure to Mediterranean eating habits and lifestyle. Methods The sample consisted of 1046 non‐demented individuals over the age of 64 (mean age = 73.1; SD = 5.0), with available baseline dietary information and longitudinal follow‐up. Diagnosis of dementia was made by a full clinical and neuropsychological evaluation, while cognitive performance was assessed according to five cognitive domains (memory, language, attention‐speed, executive functioning, visuospatial perception) and a global cognitive score. Adherence to MeDi was evaluated by an a priori score (range 0–55), derived from a detailed food frequency questionnaire. Results A total of 62 incident dementia cases occurred during a mean (SD) of 3.1 (0.9) years of follow‐up. Individuals in the highest MeDi quartile (highest adherence to MeDi) had a 72% lower risk for development of dementia, compared to those in the lowest one (p = 0.013). In addition, analysis of cognitive performance as a function of MeDi score revealed that the biennial cognitive benefit of a 10‐unit increase in MeDi score offsets the cognitive decline associated with 1 year of cognitive aging. Conclusion In the present study, higher adherence to MeDi was associated with a reduced risk for dementia and cognitive decline in a traditional Mediterranean population.

Background and objectives:Aging is characterized by a functional shift of the immune system towards a proinflammatory phenotype. This derangement has been associated with cognitive decline and has been implicated in the pathogenesis of dementia. Diet can modulate systemic inflammation; thus, it may be a valuable tool to counteract the associated risks for cognitive impairment and dementia. The present study aimed to explore the associations between the inflammatory potential of diet, assessed using an easily applicable, population-based, biomarker-validated diet inflammatory index (DII), and the risk for dementia in community-dwelling older adults.Methods:Individuals from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD) were included in the present cohort study. Participants were recruited through random population sampling, and were followed for a mean of 3.05 (SD=0.85) years. Dementia diagnosis was based on standard clinical criteria. Those with baseline dementia and/or missing cognitive follow-up data were excluded from the analyses. The inflammatory potential of diet was assessed through a DII score which considers literature-derived associations of 45 food parameters with levels of pro- and anti-inflammatory cytokines in the blood; higher values indicated a more pro-inflammatory diet. Consumption frequencies were derived from a detailed food frequency questionnaire, and were standardized to representative dietary intake normative data from 11 different countries. Analysis of dementia incidence as a function of baseline DII scores was performed by Cox proportional hazards models.Results:Analyses included 1059 individuals (mean age=73.1 years; 40.3% males; mean education=8.2 years), 62 of whom developed incident dementia. Each additional unit of DII was associated with a 21% increase in the risk for dementia incidence [HR=1.21 (1.03 – 1.42); p=0.023]. Compared to participants in the lowest DII tertile, participants in the highest one (maximal pro-inflammatory diet potential) were 3 [(1.2 – 7.3); p=0.014] times more likely to develop incident dementia. The test for trend was also significant, indicating a potential dose-response relationship (p=0.014).Conclusions:In the present study, higher DII scores (indicating greater pro-inflammatory diet potential) were associated with an increased risk for incident dementia. These findings might avail the development of primary dementia preventive strategies through tailored and precise dietary interventions.