Nutritional interventions for the prevention of cognitive impairment and dementia in developing economies in East-Asia: a systematic review and meta-analysis.

Dementia represents a key impending global health challenge. The aim of this systematic review was to evaluate the current evidence on nutritional interventions for the prevention of dementia in developing economies in East-Asia. Four comprehensive databases were searched from inception until January 2020: MEDLINE, Embase, PsycInfo, and Scopus. The search was restricted to randomized controlled trials [RCTs] in adult humans, assessing the effect of nutritional interventions on global and domain specific cognitive performance and dementia risk. Meta-analysis of data was conducted for each domain and sub-categorized according to the type of nutritional intervention. Twenty-four RCTs were included, of which, fifteen studies showed significant beneficial effects on cognition. Eighteen studies were included in the meta-analysis. Significant beneficial effects were found for essential fatty acids (EPA/DHA) and micronutrient supplementation on specific cognitive domains including attention and orientation, perception, verbal functions and language skills. The effect size of the interventions appeared to be greater in older subjects with cognitive impairment. Supplementation with B-vitamins and essential fatty acids may represent promising strategies to minimize age-related cognitive decline in Asian populations. Large, high-quality, long-term trials are needed to confirm these findings.

Prevalence and Risk of Mild Cognitive Impairment in Low and Middle-Income Countries: A Systematic Review.

BACKGROUND: Mild cognitive impairment (MCI) is a cognitive state associated with increased risk of dementia. Little research on MCI exists from low-and middle-income countries (LMICs), despite high prevalence of dementia in these settings. OBJECTIVE: This systematic review aimed to review epidemiological reports to determine the prevalence of MCI and its associated risk factors in LMICs. METHODS: Medline, Embase, and PsycINFO were searched from inception until November 2019. Eligible articles reported on MCI in population or community-based studies from LMICs and were included as long as MCI was clearly defined. RESULTS: 5,568 articles were screened, and 78 retained. In total, n = 23 different LMICs were represented; mostly from China (n = 55 studies). Few studies were from countries defined as lower-middle income (n = 14), low income (n = 4), or from population representative samples (n = 4). There was large heterogeneity in how MCI was diagnosed; with Petersen criteria the most commonly applied (n = 26). Prevalence of amnesic MCI (aMCI) (Petersen criteria) ranged from 0.6%to 22.3%. Similar variability existed across studies using the International Working Group Criteria for aMCI (range 4.5%to 18.3%) and all-MCI (range 6.1%to 30.4%). Risk of MCI was associated with demographic (e.g., age), health (e.g., cardio-metabolic disease), and lifestyle (e.g., social isolation, smoking, diet and physical activity) factors. CONCLUSION: Outside of China, few MCI studies have been conducted in LMIC settings. There is an urgent need for population representative epidemiological studies to determine MCI prevalence in LMICs. MCI diagnostic methodology also needs to be standardized. This will allow for cross-study comparison and future resource planning.

Sarcopenic obesity and overall mortality: Results from the application of novel models of body composition phenotypes to the National Health and Nutrition Examination Survey 1999-2004.

BACKGROUND/OBJECTIVES: There is no consensus on the definition of sarcopenic obesity (SO), resulting in inconsistent associations of SO with mortality risk. We aim to evaluate association of dual energy x-ray absorptiometry (DXA) SO models with mortality risk in a US adult population (≥50 years). SUBJECTS/METHODS: The study population consisted of 3577 participants aged 50 years and older from the 1999-2004 National Health and Nutrition and Examination Survey with mortality follow-up data through December 31, 2011. Difference in survival time in people with and without SO defined by three body composition DXA models (Model 1: body composition phenotype model; Model 2: Truncal Fat Mass (TrFM)/Appendicular Skeletal Muscle Mass (ASM) ratio model; Model 3: Fat Mass (FM)/Fat Free Mass (FFM) ratio). The differences between the models were assessed by the acceleration failure time model, and expressed as time ratios (TR). RESULTS: Participants age 50-70 years with SO had a significantly decreased survival time, according to the body composition phenotype model (TR: 0.92; 95% CI: 0.87-0.97), and TrFM/ASM ratio model (TR: 0.88; 95% CI: 0.81-0.95). The FM/FFM ratio model did not detect significant differences in survival time. Participants with SO aged 70 years and older did not have a significantly decreased survival time, according to all three models. CONCLUSIONS: A SO phenotype increases mortality risk in people of age 50-70 years, but not in people aged 70 years and older. The application of the body composition phenotype and the TrFM/ASM ratio models may represent useful diagnostic approaches to improve the prediction of disease and mortality risk.