Maternal Dietary Nitrate Intake and Risk of Neural Tube Defects: A Systematic Review and Dose-Response Meta-Analysis Publisher Pubmed



Kakavandi NR^{1, 2} ; Hasanvand A³ ; Ghazikhansari M⁴ ; Sezavar AH^{1, 2} ; Nabizadeh H^{1, 5} ; Parohan M^{1, 6} Show Affiliations
Source: Food and Chemical Toxicology Published:2018

Abstract

Despite growing evidence for the potential teratogenicity of nitrate, knowledge about the dose-response relationship of dietary nitrate intake and risk of specific birth defects such as neural tube defects (NTDs) is limited. Therefore, the aim of this meta-analysis was to synthesize the knowledge about the dose-response relation between maternal dietary nitrate intake and the risk of NTDs. We conducted a systematic search in PubMed, ISI Web of Science and Scopus up to February 2018 for observational studies. Risk ratios (RRs) and 95% confidence intervals (95% CI) were calculated using a random-effects model for highest versus lowest intake categories. The linear and non-linear relationships between nitrate intake and risk of NTDs were also investigated. Overall, 5 studies were included in the meta-analyses. No association was observed between nitrate intake and NTDs risk in high versus low intake (RR: 1.33; 95% CI: 0.89–1.99, p = 0.158) and linear dose-response (RR: 1.03; 95% CI: 0.99–1.07, p = 0.141) meta-analysis. However, there were positive relationships between nitrate intake and risk of NTDs in non-linear (pnon-linearity<0.05) model. Findings from this dose-response meta-analysis indicate that maternal nitrate intake higher than ∼3 mg/day is positively associated with NTDs risk. © 2018 Elsevier Ltd