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Background and ObjectivesAging is characterized by a functional shift of the immune system toward 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 risk for cognitive impairment and dementia. The present study aimed to explore the associations between the inflammatory potential of diet, assessed with an easily applicable, population-based, biomarker-validated diet inflammatory index (DII), and the risk for dementia in community-dwelling older adults.MethodsIndividuals 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 up for a mean of 3.05 (standard deviation 0.85) years. Dementia diagnosis was based on standard clinical criteria. Those with baseline dementia or missing cognitive follow-up data were excluded from the analyses. The inflammatory potential of diet was assessed through a DII score that considers literature-derived associations of 45 food parameters with levels of proinflammatory and anti-inflammatory cytokines in the blood; higher values indicated a more proinflammatory 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.ResultsAnalyses included 1,059 individuals (mean age 73.1 years, 40.3% male, mean education 8.2 years), 62 of whom developed incident dementia. Each additional unit of DII score was associated with a 21% increase in the risk for dementia incidence (hazard ratio 1.21 [95% confidence interval 1.03–1.42]; p = 0.023). Compared to participants in the lowest DII score tertile, participants in the highest one (maximal proinflammatory diet potential) were 3 (95% confidence interval 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).DiscussionIn the present study, higher DII scores (indicating greater proinflammatory 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.

Objectives Recently a declining trend in dementia incidence rates has been reported in high-income countries. We investigated dementia incidence in a representative sample of the Greek population in the age group of 65 years and above. Methods This research is part of the Hellenic Epidemiological Longitudinal Investigation of Aging and Diet (HELIAD). The incidence cohort consisted of 1072 participants who were reevaluated after a mean period of 3.09 years. Results The incidence rate of dementia was 19.0 cases per 1000 person-years (age-standardized and sex-standardized incidence: 25.4/1000 person-years), of which 16.3 per 1000 person-years were attributable to Alzheimer disease. Each additional year of age increased dementia risk by 19.3% and each additional year of education decreased dementia risk by 12.1%. Apolipoprotein E (APOE)-e4 homozygous participants were 18 times more likely to be diagnosed with dementia. A baseline diagnosis of mild cognitive decline (MCI) resulted in a risk for dementia increased by 3.7 times compared with the cognitively normal; in participants with MCI at baseline, APOE-e4 carriage increased dementia risk by 4.5 times. Conclusions The incidence rate of dementia in people 65 years and above in Greece is generally consistent with recently published rates in Europe and North America. Advancing age, baseline MCI, and APOE-e4 homozygosity are risk factors, while higher educational attainment seems protective.

Introduction Timely recognition of mild cognitive impairment (MCI) is essential in optimizing prevention and treatment for Alzheimer disease. Because of the paucity of data on MCI epidemiology in Greece and the variability of worldwide published results, we investigated the prevalence and determinants of MCI in the elderly population in Greece. Methods As part of the Hellenic Epidemiological Longitudinal Investigation of Aging and Diet (HELIAD), we randomly selected 1960 individuals 65 years and older to undergo full neurological and neuropsychological assessment by a multidisciplinary team. MCI was diagnosed according to the Petersen criteria. Results The age-standardized and gender-standardized prevalence of MCI in people aged 65 years and older in Greece is 13.11%. The amnestic and multidomain MCI subtypes are more common than their nonamnestic and single-domain counterparts, respectively. Almost two thirds of cases are because of suspected Alzheimer disease. Every additional year of age increases the odds of prevalent MCI by 7.4%, every additional year of education decreases the odds of MCI by 6.3%, and apolipoprotein E (APOE-e4) carriage increases the odds of MCI by 57.9%. Conclusions MCI prevalence in the elderly population in Greece is on par with previously reported rates. Prospective studies with robust methodology will enhance our understanding of the dementia continuum.