Early Life Exposure to Green Space Linked to Mid-Childhood Cognition

Among the top attributes people look for in a neighborhood is access to green space. Science backs up this notion, with studies showing that proximity to parks and plants are good for our health. Knowing that early life is a crucial window for brain growth and development, a new study asks, what can access to green space do to children’s cognitive development? The study of Massachusetts children finds that exposure to green space in early childhood was associated with better visual memory at mid-childhood (at around the 8-year mark). The results are published in the journal American Epidemiology. Co-author Marianthi-Anna Kioumourtzoglou is an assistant professor of environmental health sciences at Columbia University Mailman School of Public Health and a member of the NIEHS Center for Environmental Health in Northern Manhattan.

Yet, according to the study, the benefits of green space may not be universal. The researchers observed that living in proximity to green space did not improve the visual memory of children whose parents had relatively little education. According to the researchers, these parents might have jobs that keep them and children from enjoying outdoor space. So, what is it that green space does that is good for some young brains? The researchers explored two possibilities—lower air pollution and increased physical activity. They found neither mediated the effect of green space, but say the results should be confirmed in future studies.   

Using satellite images to quantify green space, the researchers examined childhood cognitive development at early and mid-childhood. These children were part of the Project Viva cohort, a group of children and their mothers in Massachusetts enrolled in a research cohort from 1999 to 2010. Children were assessed in different areas of cognitive development, such as vocabulary, visual and motor skills, and visual memory, at different points. The authors investigated changes in development at around 3 and 8 years of age—crucial milestones of brain development. A total of 852 children were included for analysis. Finally, in order to fully capture any meaningful association between green space and development, the researchers adjusted for child race, sex, and age, mothers’ intelligence, parent educational attainment, annual household income, neighborhood median income, and neighborhood population density.

Marcia P Jimenez, Jessica Shoaff, Marianthi-Anna Kioumourtzoglou, Susan Korrick, Sheryl L Rifas-Shiman, Marie-France Hivert, Emily Oken, Peter James, Early Life Exposure to Green Space and Mid-childhood Cognition in the Project Viva Cohort (Massachusetts, USA), American Journal of Epidemiology, 2021;, kwab209, https://doi.org/10.1093/aje/kwab209