Exposure to green space can boost cognitive health.

An NIA-funded study found that living environments with more green space were associated with faster thinking, better concentration and overall cognitive function in middle-aged women. Published in JAMA Network Open; The findings suggest that green space – such as trees, flowers, grass, parks and gardens – can be explored as a community-based approach to improving cognitive health.

For this study, a team of researchers from Boston University, Harvard University and the Rush University Alzheimer’s Center in Chicago analyzed cognitive test and residential green space data from 13,594 women with an average age of 61. The women were enrolled in Nurses’ Health. Study II, a longitudinal study examining the risk of major chronic diseases in women. The participants took online cognitive tests that measured psychomotor speed, attention, learning, and working memory. Then, using satellite image-based technology, the researchers determined the green space around each participant’s home. Researchers assessed the relationship between the amount of green space within walking distance of a participant’s home and their cognitive function.

They found that women who lived in areas with more green space scored higher in thinking speed, attention and overall cognitive function. Cognitively, this translates to 1.2 years younger. However, living in an environment with green space did not improve learning or memory, which included tracking information while performing a task. This finding is consistent with another study that found living in neighborhoods with green space was unrelated to the size of the hippocampus, the part of the brain responsible for memory and learning.

Next, the team tested several factors that influence cognition, including neighborhood socioeconomic status (SES). In particular, the positive relationship between green space and thinking speed and attention, as well as general cognitive function, was greater among women living in neighborhoods with higher SES. They also found that the effect of green space on intelligence was not significantly affected by population size. This indicates that the cognitive benefits of green space are transferred to different locations, such as urban neighborhoods.

Previous studies have shown that green space is associated with reduced pollution, lower levels of depression and increased physical activity – all of which have a positive effect on cognition. In this study, the researchers found that the positive effects of green space on thinking speed, attention and general cognitive function could not be explained by air quality or physical activity. However, they found that the cognitive benefits of living near green space may be partly a reduction in depression. This explanation is supported by previous findings that higher exposure to green space is associated with lower levels of depression. As depression is a risk factor for dementia, these results suggest that using green space may help reduce dementia.

According to the authors, most of the participants were white; Therefore, more research is needed to understand how racial differences and socioeconomic factors affect the relationship between green space and cognitive function. He also suggested that future research should examine how people interact with the green space around them.

This national study shows that exposure to green space can support cognitive health. Moreover, the findings support the need for more research on green space exposure to reduce the risk of cognitive decline and dementia in the elderly.

This research was supported in part by NIA grants. 1K99AG066949-02, R01AG067497, and R01AG065359.

These activities are relatedNIH AD+ADRD Research Implementation Chapter 2.H, “Continue to support unique epidemiology research to discover and understand common diseases between AD and other neurodegenerative disorders, including rare diseases, and use these for treatment development.

Jimenez MP, et al. Residential green space and cognitive function among middle-aged women in a large cohort. JAMA Network Open. 2022;5(4):e229306. doi: 10.1001/jamanetworkopen.2022.9306.