A Meta-Analysis of Stressors from the Total Environment Associated with Children’s General Cognitive Ability

Abstract

General cognitive ability, often referred to as ‘general intelligence’, comprises a variety of correlated abilities. Childhood general cognitive ability is a well-studied area of research and can be used to predict social outcomes and perceived success. Early life stage (e.g., prenatal, postnatal, toddler) exposures to stressors (i.e., chemical and non-chemical stressors from the total (built, natural, social) environment) can impact the development of childhood cognitive ability. Building from our systematic scoping review (Ruiz et al., 2016), we conducted a meta-analysis to evaluate more than 100 stressors related to cognitive development. Our meta-analysis identified 23 stressors with a significant increase in their likelihood to influence childhood cognitive ability by 10% or more, and 80 stressors were observed to have a statistically significant effect on cognitive ability. Stressors most impactful to cognition during the prenatal period were related to maternal health and the mother’s ability to access information relevant to a healthy pregnancy (e.g., diet, lifestyle). Stressors most impactful to cognition during the early childhood period were dietary nutrients (infancy), quality of social interaction (toddler), and exposure to toxic substances (throughout early childhood). In conducting this analysis, we examined the relative impact of real-world exposures on cognitive development to attempt to understand the inter-relationships between exposures to both chemical and non-chemical stressors and early developmental life stages. Our findings suggest that the stressors observed to be the most influential to childhood cognitive ability are not permanent and can be broadly categorized as activities/behaviors which can be modified to improve childhood cognition. This meta-analysis supports the idea that there are complex relationships between a child’s total environment and early cognitive development.

Iron deficiency and cognitive impairment in children with low blood lead levels

“…This suggests that the child probably interacts better when surrounded by family members and thus develops working memory skills. In this sense, a recent meta-analysis supports the idea that the quality of social interaction is one of the stress factors that impact the development of cognitive abilities during the early childhood period [62] .…”

Fatores associados ao desenvolvimento infantil em crianças brasileiras: linha de base da avaliação do impacto do Programa Criança Feliz

“…Assim como observado neste estudo, estimativas agrupadas em estudos de metanálise identificaram relação positiva, com gradiente dose-resposta, entre escolaridade dos pais e escores de desenvolvimento infantil 11 . Nilsen et al 25 realizaram uma metanálise que avaliou dados de 185 estudos. Foram analisados mais de 100 fatores estressores maternos e seus efeitos sobre as habilidades cognitivas em crianças e adolescentes menores de 18 anos.…”

“…Foram analisados mais de 100 fatores estressores maternos e seus efeitos sobre as habilidades cognitivas em crianças e adolescentes menores de 18 anos. Os estressores socioeconômicos, entre eles a baixa escolaridade materna, foram responsáveis por 13% e 18% do atraso de desenvolvimento de habilidades cognitivas em crianças e adolescentes, respectivamente 25 . A literatura sobre os efeitos da escolaridade materna na saúde infantil 26,27,28,29 explica esta associação a partir de mecanismos indiretos, relacionados às inequidades em saúde.…”

A Benchmark Dose Analysis for Maternal Pregnancy Urine‐Fluoride and IQ in Children

“…These findings provide additional evidence that fluoride is a developmental neurotoxicant (i.e., causing adverse effects on brain development in early life). Given the ubiquity of fluoride exposure, the population impact of adverse effects from fluoride may be even greater than for other toxic elements like lead, mercury, and arsenic (Nilsen et al 2020). Adverse effects of the latter trace elements are associated with blood concentrations that are about 100-fold lower than the serum-fluoride concentration that corresponds to the benchmark concentration (Grandjean, 2019).…”