Parkinson’s disease (PD) is a frequent neurodegenerative disease among elderly people. Genetic and underlying environmental factors seem to be involved in the pathogenesis of PD related to degeneration of dopaminergic neurons in the striatum. In previous experimental researches oxidative stress, mitochondrial dysfunction, homocysteine, and neuroinflammation have been reported as potential mechanisms. Among environmental factors, nutrition is one of the most investigated areas as it is a potentially modifiable factor. The purpose of this review is to provide current knowledge regarding the relation between diet and PD risk. We performed a comprehensive review including the most relevant studies from the year 2000 onwards including prospective studies, nested case-control studies, and meta-analysis. Among dietary factors we focused on specific nutrients and food groups, alcoholic beverages, uric acid, and dietary patterns. Furthermore, we included studies on microbiota as recent findings have shown a possible impact on neurodegeneration. As a conclusion, there are still many controversies regarding the relationship between PD and diet which, beside methodological differences among studies, may be due to underlying genetic and gender-specific factors. However, some evidence exists regarding a potential protective effect of uric acid, poly-unsaturated fatty acids, coffee, and tea but mainly in men, whereas dairy products, particularly milk, might increase PD risk through contaminant mediated effect.

Objectives: In the absence of a simple validated instrument to screen for cognitive impairment among illiterate Lebanese older adults, the aims of this study were to validate an Arabic version of the Test of Nine Images (A-TNI93) adapted by the Working Group on Dementia at Saint Joseph University: Groupe de Travail sur les Démences de l’Univesité Saint Joseph (GTD-USJ) for illiterate older Lebanese and to establish normative data.Method: A national population-based sample of 332 community-dwelling illiterate Lebanese aged 55 years and older was administered the A-TNI93 (GTD-USJ) scoring free and overall recall. The sample is part of a larger national sample (1342 participants) used to validate an Arabic version of the Mini-Mental State Examination already reported. Reproducibility, sensitivity, specificity, and area under the curve of the A-TNI93 (GTD-USJ) scoring to detect cognitive impairment according to Clinical Dementia Rating (CDR) as the gold standard were measured. Normative data were established among 188 cognitively normal participants.Results: A threshold score of six on free recall (FR) provided a sensitivity of 66.7% and a specificity of 90.5%. The area under the curve was 0.93. By taking either scores, that is, a FR ≤ 6 or a total recall ≤ 8, the A-TNI93 (GTD-USJ) slightly improved dementia case detection with a sensitivity of 70.8% and a specificity of 88%. Normative data illustrate the distribution of cognitive performance among illiterate older adults.Conclusions: Compared to the CDR requiring physician’s competence, the A-TNI93 (GTD-USJ) is a valid Arabic adaptation to screen for cognitive impairment among illiterate Lebanese older adults.

Modifiable factors associated with cognitive decline (CD) require more attention, particularly dietary patterns. This study aimed to investigate the link between cognitive decline and associated factors, particularly dietary patterns (DPs), in community-dwelling older Lebanese of modest economic status. Our cross-sectional national study included 352 participants above 60 years old, from the medico-social centers of the ministry of social affairs all over the country. CD was screened based on literacy. Nutritional and dietary data were collected through a validated food frequency questionnaire. DPs were extracted by the K-mean cluster analysis. CD was found in 32.7% and 61.5% of literate and illiterate groups, respectively. Identified DPs included a Westernized type and Mediterranean type, with high and moderate food intakes. In the context of literacy, independent factors associated with CD were age above 80 years, living in Beirut, frailty, and adopting a Westernized (OR = 3.08, 95% CI: 1.22–7.8) and a high-intake Mediterranean DP (OR = 2.11, 95% CI: 1.05–4.22). In the context of illiteracy, the same factors were associated with CD, but not DP nor frailty, with an age cut-off at 78 years. In a Lebanese sample of older adults, factors associated with CD depend on the level of literacy, with DP only associated with CD in the context of literacy.