Many studies have focused on the potential physical and psychological benefits of green spaces, but only a few studies have investigated their role in cognitive development. We have already highlighted some studies on the potential effects of green spaces, in particular on improving attention in young children or on the importance of spending time in nature for our physical and mental health. Recently, researchers from University College London and Imperial College London tried to determine the effects of daily access to different natural environments in adolescents ages 9 to 15. The study aimed to determine which natural spaces are the most beneficial to the brain: forests, meadows or lakes?

For their research, Mikaël J.A Maes (a PhD student in geography and biosciences at UCL and Public Health at Imperial College London) and his colleagues used data from a cohort study of 3,568 subjects carried out between 2014 and 2018 in children and teenagers in 31 London schools. By accessing this data, they were able to examine the links between different types of natural urban environments near these schools (or homes) on cognitive development, mental health, and general well-being.

The research’s originality lies in the fact that the different environments were divided into green (woods, meadows, and parks) and blue (rivers, lakes, and sea) spaces. Forests and meadows were distinguished later. By reviewing satellite data, the team of scientists was able to assess each subject’s daily exposure rate to each of the environments within 50, 100, 250 and 500 meters of their home and school.

The young participants were given cognitive, mental, psychological and social well-being assessments at the beginning and end of the study. After adjusting for different variables (age, ethnicity, gender, parents’ socio-economic status, type of school) which could skew the results, the researchers observed that a greater daily exposure to forests (but not meadows) improved cognitive development by 2.14% and reduced the risk of emotional and behavioral problems by 16%. Although not as strong, a similar effect on cognition was noted for green spaces as a whole, but not for blue spaces (it should be noted that access to the latter was relatively limited in this particular cohort).

According to the authors, these results, “contribute to our understanding of natural environment types as an important protective factor for an adolescent’s cognitive development and mental health and suggest that not every environment type may contribute equally to these health benefits.” In addition, “the results of this study suggest that urban planning decisions to optimize ecosystem benefits linked to cognitive development and mental health should carefully consider the type of natural environment included.”