Chronic exposure to aluminum and risk of Alzheimer's disease: A meta-analysis.

A meta-analysis was performed to investigate whether chronic exposure to aluminum (Al) is associated with increased risk of Alzheimer's disease (AD). Eight cohort and case-control studies (with a total of 10567 individuals) that met inclusion criteria for the meta-analysis were selected after a thorough literature review of PubMed, Web of Knowledge, Elsevier ScienceDirect and Springer databases up to June, 2015. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of included studies. Q test and I(2) statistic were used to examine heterogeneity between selected studies. The overall odds ratio (OR) was calculated using a fixed-effect model because no significant heterogeneity between studies was found. No publication bias was observed based on a funnel plot and Egger's test. Results showed that individuals chronically exposed to Al were 71% more likely to develop AD (OR: 1.71, 95% confidence interval (CI), 1.35-2.18). The finding suggests that chronic Al exposure is associated with increased risk of AD.