scholarly journals Education and Age-related Decline in Cognitive Performance: Systematic Review and Meta-analysis of Longitudinal Cohort Studies

2019 ◽  
Author(s):  
Dominika Seblova ◽  
Rasmus Berggren ◽  
Martin Lövdén

Central theories of cognitive aging propose that education is an important protective factor for decline in cognitive performance in older age. We conducted a systematic review and meta-analysis of reported estimates of an association between educational attainment and change in performance in six cognitive domains (episodic memory, processing speed, verbal fluency, crystallized intelligence, fluid intelligence, and global ability) in the general population of older individuals. The systematic search (28th of September, 2018) identified 83 eligible articles. The episodic memory domain had the highest number of estimates (37 estimates from 17 articles, n=109,281) included in the meta-analysis. The fewest estimates (5 estimates from 5 articles, n=5,263) were included for fluid intelligence. Pooled mean estimates from an inverse-variance weighted random effects analysis were not statistically significant and indicated that any association between education and change in cognitive performance is likely to be of a negligible magnitude. Sensitivity analyses did not substantially alter these results. However, heterogeneity was substantial, and remained largely unexplained by mean age, mean educational attainment, maximum follow-up period, and publication year. Overall education is an important factor in aging due to its robust association with level of performance. However, we conclude that the current base of empirical evidence is not revealing a consistent and substantial association between educational attainment and changes in cognitive performance in the general population. Theories of cognitive aging must be updated to incorporate this pattern of findings.

Author(s):  
Yanjie Zhang ◽  
Chunxiao Li ◽  
Liye Zou ◽  
Xiaolei Liu ◽  
Wook Song

Background: As the situation of cognitive aging is getting worse, preventing or treating cognitive decline through effective strategies is highly important. This systematic review aims to investigate whether mind-body exercise is an effective approach for treating cognition decline. Methods: Searches for the potential studies were performed on the eight electronic databases (MEDLINE, Scopus, Web of Science, SPORTDiscus, CINAHL, PsycArtilces, CNKI, and Wanfang). Randomized controlled trials (RCTs) examining the effect of mind-body exercise on cognitive performance in older adults were included. Data were extracted and effect sizes were pooled with 95% confidence intervals (95% CI) using random-effects models. The Physiotherapy Evidence Database Scale was employed to examine the study quality. Results: Nineteen RCTs including 2539 elders (67.3% female) with fair to good study quality were identified. Mind-body exercise, relative to control intervention, showed significant benefits on cognitive performance, global cognition (Hedges’g = 0.23), executive functions (Hedges’g = 0.25 to 0.65), learning and memory (Hedges’g = 0.37 to 0.49), and language (Hedges’g = 0.35). In addition, no significant adverse events were reported. Conclusion: Mind-body exercise may be a safe and effective intervention for enhancing cognitive function among people aged 60 years or older. Further research evidence is still needed to make a more conclusive statement.


Rheumatology ◽  
2020 ◽  
Vol 60 (1) ◽  
pp. 60-72 ◽  
Author(s):  
José María Pego-Reigosa ◽  
Lindsay Nicholson ◽  
Nick Pooley ◽  
Sue Langham ◽  
Nina Embleton ◽  
...  

Abstract Objectives We conducted a systematic review and meta-analysis to determine the magnitude of infection risk in patients with SLE and evaluate the effect of general and SLE-related factors on infection risk. Methods We searched MEDLINE and Embase from inception to July 2018, screening for observational studies that evaluated infection risk in patients with SLE compared with the general population/healthy controls. Outcomes of interest included overall severe infection, herpes zoster infection/reactivation, opportunistic infections, pneumonia and tuberculosis. Random-effects models were used to calculate pooled risk ratios (RRs) for each type of infection. Sensitivity analysis assessed the impact of removing studies with high risk of bias. Results Eleven retrospective or prospective cohort studies were included in the meta-analysis: overall severe infection (n = 4), pneumonia (n = 6), tuberculosis (n = 3) and herpes zoster (n = 2). Pooled RRs for overall severe infection significantly increased for patients with SLE compared with the general population/healthy controls [RR 2.96 (95% CI 1.28, 6.83)]. Pooled RRs for pneumonia, herpes zoster and tuberculosis showed significantly increased risk compared with the general population/healthy controls [RR 2.58 (1.80, 3.70), 2.50 (2.36, 2.65) and 6.11 (3.61, 10.33), respectively]. Heterogeneity and evidence of publication bias were present for all analyses, except herpes zoster. Sensitivity analyses confirmed robustness of the results. Conclusion Patients with SLE have significantly higher risk of infection compared with the general population/healthy controls. Efforts to strengthen strategies aimed at preventing infections in SLE are needed. Protocol registration PROSPERO number: CRD42018109425.


2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 905-905
Author(s):  
Chantelle Gaylor ◽  
Hayley Young ◽  
David Benton

Abstract Objectives A systematic review and meta-analysis compared the effects of high (HGL) and low glycemic load (LGL) breakfasts on the cognitive performance of adults. In particular, the time after eating that cognition was assessed and the influence of pre-existing glucose tolerance (GT) were considered. Methods A systematic search for randomized and non-randomized acute breakfast studies was conducted using PubMed, Scopus, and Cochrane Library. Data were available from 15 studies (1,100 participants, age 20–80 years). Episodic memory (e.g., word list recall), working memory (e.g., Serial Sevens), and attention/vigilance (e.g., Trails Part A) were examined. Better and poorer GT were defined as fasting glucose < or > 6.1 mmol/L (110 mg/dL) and/or two-hour postprandial glucose < or > 7 mmol/L (126 mg/dL). All analyses were performed using RevMan 5.3 (Cochrane) and a random-effects model. Results Five to 110 minutes after eating a HGL or LGL breakfast there were no differences cognition. However, between 120 and 195 minutes, immediate episodic memory was significantly better following a LGL breakfast (SMD = 0.16, 95% confidence interval [CI] = –0.00–0.32, P = 0.05, I2 = 0%). Pre-existing glucose tolerance (GT) status moderated this effect. In those with better GT, immediate episodic memory was significantly better following a LGL breakfast (SMD = 0.26, 95% CI = 0.00–0.52, P = 0.05, I2 = 0%), whereas there was no difference in those with poorer GT (SMD = 0.12, 95% CI = –0.21–0.45, P = 0.47, I2 = 0%). Conclusions A LGL breakfast improved memory later in the morning, especially in those with better GT. The phenomenon is unlikely to occur in pre-diabetics or type 2 diabetics and as such there are no clinical implications. There is, however, a possibility of exploring the nature of breakfast, or developing functional foods, to improve memory and work performance. If a similar phenomenon was found in children, there could be positive consequences for school performance. Funding Sources This study was not funded.


2020 ◽  
Author(s):  
A Lehner ◽  
K Staub ◽  
L Aldakak ◽  
P Eppenberger ◽  
F Rühli ◽  
...  

Abstract Introduction The omega-3 long-chain polyunsaturated fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are important for brain development and cognitive performance. Because they are semi-essential fatty acids, they must be obtained from food. However, the dietary reference intakes of DHA and EPA have not yet been established. In women, a low DHA and/or EPA serum level during pregnancy or breastfeeding might negatively affect their children. For this study, we conducted a systematic review and meta-analysis of randomized control trials on the association between the consumption of fish oil supplements in pregnant and/or breastfeeding women and the cognitive performance of their children. Methods The PubMed, Embase, and Central literature databases were systematically searched. We included and extracted relevant studies in duplicate and assessed study quality. Cognitive outcomes were grouped according to published criteria and according to time elapsed after the intervention. We performed fixed-effects meta-analyses for each cognitive outcome and for birth weight. We assessed potential confounding with meta-regressions and sensitivity analyses. Results A total of 11 trials were included. No significant association was found between DHA/EPA supplementation and any of the assessed cognitive parameters or birth weight. Discussion Our results confirm previous reviews on the studied topic. Reasons for inconclusive results may be small sample sizes for each assessed category, questionable quality of included studies, and the difficulty of reliably measuring cognitive performance in small children. Blood levels of omega-3 long-chain polyunsaturated fatty acids were mostly not comparable. Furthermore, the influence of genetic and environmental factors could not be assessed. Studies in this field should address such shortcomings.


Author(s):  
Frédéric Dutheil ◽  
Benjamin Danini ◽  
Reza Bagheri ◽  
Maria Livia Fantini ◽  
Bruno Pereira ◽  
...  

Background: Napping in the workplace is under debate, with interesting results on work efficiency and well-being of workers. In this systematic review and meta-analysis, we aimed to assess the benefits of a short daytime nap on cognitive performance. Methods: PubMed, Cochrane Library, ScienceDirect and PsycInfo databases were searched until 19 August 2021. Cognitive performance in working-aged adults, both before and following a daytime nap or under control conditions (no nap), was analysed by time and by type of cognitive function (alertness, executive function and memory). Results: We included 11 studies (all in laboratory conditions including one with a subgroup in working conditions) for a total of 381 participants. Mean duration of nap was 55.4 ± 29.4 min. Overall cognitive performance did not differ at baseline (t0) between groups (effect size −0.03, 95% CI −0.14 to 0.07), and improved in the nap group following the nap (t1) (0.18, 0.09 to 0.27), especially for alertness (0.29, 0.10 to 0.48). Sensitivity analyses gave similar results comparing only randomized controlled trials, and after exclusion of outliers. Whatever the model used, performance mainly improved until 120 min after nap, with conflicting results during the sleep inertia period. Early naps in the afternoon (before 1.00 p.m.) gave better cognitive performance (0.24, −0.07 to 0.34). The benefits of napping were independent of sex and age. Duration of nap and time between nap and t1 did not influence cognitive performance. Conclusions: Despite the fact that our meta-analyses included almost exclusively laboratory studies, daytime napping in the afternoon improved cognitive performance with beneficial effects of early nap. More studies in real work condition are warranted before implementing daytime napping at work as a preventive measure to improve work efficiency.


Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 868
Author(s):  
Jorge Lorenzo Calvo ◽  
Xueyin Fei ◽  
Raúl Domínguez ◽  
Helios Pareja-Galeano

Cognitive functions are essential in any form of exercise. Recently, interest has mounted in addressing the relationship between caffeine intake and cognitive performance during sports practice. This review examines this relationship through a structured search of the databases Medline/PubMed and Web of Science for relevant articles published in English from August 1999 to March 2020. The study followed PRISMA guidelines. Inclusion criteria were defined according to the PICOS model. The identified records reported on randomized cross-over studies in which caffeine intake (as drinks, capsules, energy bars, or gum) was compared to an identical placebo situation. There were no filters on participants’ training level, gender, or age. For the systematic review, 13 studies examining the impacts of caffeine on objective measures of cognitive performance or self-reported cognitive performance were selected. Five of these studies were also subjected to meta-analysis. After pooling data in the meta-analysis, the significant impacts of caffeine only emerged on attention, accuracy, and speed. The results of the 13 studies, nevertheless, suggest that the intake of a low/moderate dose of caffeine before and/or during exercise can improve self-reported energy, mood, and cognitive functions, such as attention; it may also improve simple reaction time, choice reaction time, memory, or fatigue, however, this may depend on the research protocols.


BMJ Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. e040061
Author(s):  
Getinet Ayano ◽  
Asmare Belete ◽  
Bereket Duko ◽  
Light Tsegay ◽  
Berihun Assefa Dachew

ObjectivesTo assess the global prevalence estimates of depressive symptoms, dysthymia and major depressive disorders (MDDs) among homeless people.DesignSystematic review and meta-analysis.Data sourcesDatabases including PubMed, Scopus and Web of Science were systematically searched up to February 2020 to identify relevant studies that have reported data on the prevalence of depressive symptoms, dysthymia and MDDs among homeless people.Eligibility criteriaOriginal epidemiological studies written in English that addressed the prevalence of depressive problems among homeless people.Data extraction and synthesisA random-effect meta-analysis was performed to pool the prevalence estimated from individual studies. Subgroup and sensitivity analyses were employed to compare the prevalence across the groups as well as to identify the source of heterogeneities. The Joanna Briggs Institute’s quality assessment checklist was used to measure the study quality. Cochran’s Q and the I2 test were used to assess heterogeneity between the studies.ResultsForty publications, including 17 215 participants, were included in the final analysis. This meta-analysis demonstrated considerably higher prevalence rates of depressive symptoms 46.72% (95% CI 37.77% to 55.90%), dysthymia 8.25% (95% CI 4.79% to 11.86%), as well as MDDs 26.24% (95% CI 21.02% to 32.22%) among homeless people. Our subgroup analysis showed that the prevalence of depressive symptoms was high among younger homeless people (<25 years of age), whereas the prevalence of MDD was high among older homeless people (>50 years of age) when compared with adults (25–50 years).ConclusionThis review showed that nearly half, one-fourth and one-tenth of homeless people are suffering from depressive symptoms, dysthymia and MDDs, respectively, which are notably higher than the reported prevalence rates in the general population. The findings suggest the need for appropriate mental health prevention and treatment strategies for this population group.


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