Association between Mediterranean diet and dementia and Alzheimer disease: a systematic review with meta-analysis

Abstract

Background Dementia affects 5–8% of the population aged over 65 years (~50 million worldwide). Several factors are associated with increased risk, including diet. The Mediterranean diet (MedDiet) has shown potential protective effects against several chronic diseases. Aims This systematic review with meta-analysis aim was to assess the association between adherence to the MedDiet and the risk of dementia in the elderly. Methods PRISMA-2020 guidelines were followed. PubMed/MEDLINE and Scopus were searched on 17 July 2023. The Newcastle–Ottawa Scale tool was used to assess the risk of bias. The protocol was pre-registered in PROSPERO (registration number: CRD 42023444368). Heterogeneity was assessed using the I2 test. Publication bias was assessed by visual inspection of the funnel plot and by Egger’s regression asymmetry test. The final effect size was reported as OR or HR, depending on the study design of the included studies. Results Out of 682 records, 21 were included in the analysis. The pooled OR was 0.89 (95% CI = 0.84–0.94) based on 65,955 participants (I2 = 69.94). When only cohort studies were included, HR was 0.84 (95% CI = 0.76–0.94) based on 55,205 participants (I2 = 89.70). When only Alzheimer Disease was considered OR was 0.73 (95% CI = 0.62–0.85) based on 38,292 participants (I2 = 63.85). Discussion Despite the relatively low risk reduction associated with higher adherence to MedDiet among elderly, it should be considered that this population is the most affected. Conclusions Adherence to MedDiet could be an effective non-pharmacological measure to reduce the burden of dementia, even among elderly.

Mediterranean Dietary Pattern for Healthy and Active Aging: A Narrative Review of An Integrative and Sustainable Approach

“…As presented in Table 1 , considering only the most recent years, there are a number of reliable systematic reviews showing its protective effect. A high adherence to the Mediterranean diet had been associated with a reduced risk of all-cause mortality, cardiovascular disease risk, type 2 diabetes, cancer risk and mortality from all causes in cancer survivors [ 17 , 33 , 34 , 35 , 36 , 37 , 38 ]. Table 1 show a summary of the systematic reviews related to the relationship between adherence to the Mediterranean diet and the risk of developing different non-communicable chronic diseases and cognitive decline with updated data from over the last few years and incorporating relevant new evidence.…”

Study Protocol for the Residents’ Mental Health Investigation, a Dynamic Longitudinal Study in Italy (ReMInDIt)

“…As such, it has already been linked to a number of favorable health outcomes, first and foremost in the prevention of cardiovascular disease [20]. More recently, research has explored its role in the neuropsychological domain, such as in the prevention of Alzheimer's disease or the treatment of depression [21,22].…”