scholarly journals The Association Between Folate and Alzheimer's Disease: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 15 ◽  
Author(s):  
Xiaohong Zhang ◽  
Guangyi Bao ◽  
Debiao Liu ◽  
Yu Yang ◽  
Xuezhi Li ◽  
...  

Alzheimer's disease (AD) is the most common type of neurodegenerative disease leading to dementia in the elderly. Increasing evidence indicates that folate plays an important role in the pathogenesis of AD. To investigate the role of folate deficiency/possible deficiency in the risk of AD and the benefical effect of sufficient folate intake on the prevention of AD, a systematic review and meta-analysis were performed. The Web of Science, PubMed, CENTRAL, EBSCO, CNKI, CQVIP, and Wanfang databases were searched. The analysis of cross-sectional studies showed that the standardized mean difference (SMD) was −0.60 (95% confidence interval (CI): −0.65, −0.55), indicating that plasma/serum folate level is lower in AD patients than that in controls. Moreover, the combined odds ratio (OR) of case-control studies was 0.96 (95% CI: 0.93, 0.99), while the combined ORs were 0.86 (95% CI: 0.46, 1.26) and 1.94 (95% CI: 1.02, 2.86) in populations with normal levels of folate (≥13.5 nmol/L) and folate deficiency/possible deficiency (<13.5 nmol/L), respectively. In addition, the risk ratio (RR) of the cohort studies was 1.88 (95% CI: 1.20, 2.57) in populations with folate deficiency/possible deficiency. Furthermore, when the intake of folate was equal to or higher than the recommended daily allowance, the combined RR and hazard ratio (HR) were 0.44 (95% CI: 0.18, 0.71) and 0.76 (95% CI: 0.52, 0.99), respectively. These results indicate that folate deficiency/possible deficiency increases the risk for AD, while sufficient intake of folate is a protective factor against AD.

2017 ◽  
Vol 48 (1-2) ◽  
pp. 21-31 ◽  
Author(s):  
Yago Leira ◽  
Clara Domínguez ◽  
Juan Seoane ◽  
Juan Seoane-Romero ◽  
Juan Manuel Pías-Peleteiro ◽  
...  

Background: In the last decade, several observational studies have suggested that there exists an association between periodontal disease (PD) and Alzheimer's disease (AD). The aim of this systematic review was to investigate whether or not this link exists. Summary: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guideline for systematic review was used and registered at PROSPERO (CRD42016035377). The search strategy included using electronic databases and by hand searching articles published up to January 2016. MEDLINE via PubMed, EMBASE and Web of Science were searched by 2 independent reviewers. Observational studies including patients meeting criteria for both AD and PD were eligible to be included in the analysis. Quality assessment of selected studies was performed by the Newcastle-Ottawa Scale. From a total of 550 titles and abstracts, 5 studies were included (2 cross-sectional, 2 case-control and one cohort study) in the review. A fixed effects meta-analysis showed that the presence of PD is associated with the presence of AD (OR 1.69, 95% CI 1.21-2.35). When only severe forms of PD were evaluated, a significant association was also observed (OR 2.98, 95% CI 1.58-5.62). Key Messages: In the present review, a significant association was observed between PD and AD. Further studies should be carried out in order to investigate the direction of the association and factors that may confound it.


2019 ◽  
Vol 7 (2) ◽  
pp. 49 ◽  
Author(s):  
Mario Dioguardi ◽  
Giovanni Di Gioia ◽  
Giorgia Apollonia Caloro ◽  
Giorgia Capocasale ◽  
Khrystyna Zhurakivska ◽  
...  

Alzheimer’s disease is classified as a neurodegenerative condition, a heterogeneous group of illnesses characterized by the slow and progressive loss of one or more functions of the nervous system. Its incidence tends to increase gradually from 65 years of age, up to a prevalence of 4% at age 75. The loss of dental elements is more prevalent in this population and might negatively affect the masticatory capacity, quality of life, and pathogenesis of Alzheimer’s disease. This study investigated problems related to oral health and the loss of dental elements in elderly patients suffering from Alzheimer’s and considered whether local inflammatory processes could affect the etiopathogenesis of Alzheimer’s disease. The purpose of this systematic review is to identify a link between the causes leading to tooth loss and the onset/progression of Alzheimer’s disease. We also studied whether there is a higher incidence of tooth loss (primary outcome) and edentulism (secondary outcome) among Alzheimer’s patients. We searched records in electronic databases such as PubMed, EBSCO, and Web of Science using the following keywords: Alzheimer’s Disease AND periodontal, Alzheimer’s Disease AND periodontitis, dementia AND (periodontitis OR periodontal) “Alzheimer’s Disease” AND “tooth” OR “dental loss,” “dementia” AND “edentulous,” “Alzheimer’s Disease” AND “edentulous,” “dementia” AND “tooth” OR “dental loss.” The records were screened, and after applying the eligibility and inclusion criteria, nine articles were left, six of which were analyzed for the primary outcome (loss of dental elements) and six for the secondary outcome (tooth loss). Results from this meta-analysis revealed that Alzheimer’s disease patients have an increased risk of dental loss (hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.00–2.30, p = 0.05) and edentulous condition (HR 2.26, 95% CI 1.70–3.01, p < 0.001). A quantitative analysis of the included studies indicated that patients suffering from Alzheimer’s disease are characterized by a greater number of lost dental elements and general edentulism compared to the control groups.


2020 ◽  
Vol 16 (5) ◽  
pp. 450-456
Author(s):  
Danilo F. Sousa ◽  
Vivian S. Veras ◽  
Vanessa E.C.S. Freire ◽  
Maria L. Paula ◽  
Maria A.A.O. Serra ◽  
...  

Background:: It is undeniable that diabetes may cause several health complications for the population. Many of these complications are associated with poor glycemic control. Due to this, strategies to handle this problem are of great clinical importance and may contribute to reducing the various complications from diabetes. Objective: : The aim of this study was to compare the effectiveness of the passion fruit peel flour versus turmeric flour on glycemic control. Methods: This is a systematic review and meta-analysis following the PRISMA protocol. The following inclusion criteria were applied: (1) Case-control studies, cohort studies, and clinical trials, due to the improved statistical analysis and, in restrict cases, cross-sectional studies; (2) Articles published in any language. The databases used for the search were PubMed, Scopus, Web of Science, Cochrane, and LILACS. A bias analysis and a meta-analyses were undertaken using R Studio (version 3.3.1) using effect- size models. Results: : A total of 565 studies were identified from which 11 met the inclusion and exclusion criteria. Through isolated analysis, the effectiveness of turmeric flour on glycemic control was in the order of 0.73 CI (Confidence Interval) (from 0.68 to 0.79) and the effectiveness of passion fruit peel flour was 0.32 CI (0.23 to 0.45). The joint analysis resulted in 0.59 CI (0.52 to 0.68). The assessment of blood glucose was by glycated hemoglobin levels. All values were significant at a p < 0.05 level. Conclusion: Both interventions showed significant effects on glycemic control.


2021 ◽  
pp. 1-12
Author(s):  
Mingyue Qu ◽  
Hanxu Shi ◽  
Kai Wang ◽  
Xinggang Wang ◽  
Nan Yu ◽  
...  

Background: Multiple lines of evidence indicate protective effects of carotenoids in Alzheimer’s disease (AD). However, previous epidemiological studies reported inconsistent results regarding the associations between carotenoids levels and the risk of AD. Objective: Our study aims to evaluate the associations of six major members of carotenoids with the occurrence of AD by conducting a systematic review and meta-analysis. Methods: Following PRISMA guidelines, a comprehensive literature search of PubMed, Web of Science, Ebsco, and PsycINFO databases was conducted, and the quality of each included studies was evaluated by a validated scoring systems. Standardized mean differences (SMD) with 95%confidence intervals (CI) were determined by using a random effects model. Heterogeneity was evaluated by I2 statistics. Publication bias was detected using funnel plots and Egger’s test. Results: Sixteen studies, with 10,633 participants were included. Pooled analysis showed significantly lower plasma/serum levels of lutein (SMD = –0.86, 95%CI: –1.67 to –0.05, p = 0.04) and zeaxanthin (SMD = –0.59; 95%CI: –1.12 to –0.06, p = 0.03) in patients with AD versus cognitively intact controls, while α-carotene (SMD = 0.21, 95%CI: –0.68 to 0.26, p = 0.39), β-carotene (SMD = 0.04, 95%CI: –0.57 to 0.65, p = 0.9), lycopene (SMD = –0.12, 95%CI: –0.96 to 0.72, p = 0.78), and β-cryptoxanthin (SMD = –0.09, 95%CI: –0.83 to 0.65, p = 0.81) did not achieve significant differences. Conclusion: Of six major members of carotenoids, only lutein and zeaxanthin concentrations in plasma/serum were inversely related to the risk of AD. More high-quality longitudinal studies are needed to verify these findings.


2021 ◽  
pp. 101421
Author(s):  
Hema Sree G N S ◽  
V. Lakshmi Prasanna Marise ◽  
Kshreeraja S. Satish ◽  
Abhijna Vithal Yergolkar ◽  
Mamatha Krishnamurthy ◽  
...  

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