Exposure to green spaces may promote cognitive health
An NIA-funded study found that residential areas with more green space were associated with faster thinking, better attention, and better overall cognitive function in middle-aged women.was announced in JAMA network open, The findings suggest that green spaces such as trees, flowers, lawns, gardens and parks can be investigated as potential community-based approaches to improve cognitive health.
For this study, a team of researchers from the Alzheimer’s Disease Center at Boston University, Harvard University, and Rush University in Chicago analyzed cognitive tests and residential green space data from 13,594 women with an average age of 61 years. Study II, a longitudinal study examining major chronic disease risk factors in women. Participants underwent online cognitive tests that measured psychomotor speed, attention, learning, and working memory. Using satellite imagery-based techniques, the researchers then determined the amount of green space around each participant’s home. Researchers assessed the association between the amount of green space within walking distance of participants’ homes and cognitive function.
Women who lived in areas with more green space were found to have higher scores for speed of thought, attention, and overall cognitive function. Cognitively, this means she is 1.2 years younger. However, living in an area with lots of green space had no effect on learning or working memory, including tracking information while performing tasks. This finding is consistent with another study that found that living in areas with green spaces was not associated with the size of the hippocampus, the part of the brain involved in memory and learning.
Next, the team tested several factors thought to influence cognition, including neighborhood socioeconomic status (SES). In particular, positive associations between green space and thinking speed and attention, and overall cognitive function were higher among women living in areas with high SES. We also found that the impact was not significantly affected by population density. This suggests that the cognitive benefits of green spaces extend to different environments such as urban areas.
Previous studies have shown that green space is associated with lower pollution levels, lower risk of depression, and increased physical activity. All of these can have a positive impact on cognition. However, they found that some of the cognitive benefits of living near green spaces may be due to reduced rates of depression. This explanation is supported by previous findings that higher exposure to green spaces is associated with lower risk of depression. Given that depression is a risk factor for dementia, these results also suggest that the use of green spaces may help reduce the risk of dementia.
As noted by the authors, most of the participants were Caucasian. Therefore, additional research is needed to understand how racial disparities and socioeconomic factors affect the association between green space and cognitive function. They also noted that future research should explore how people interact with the green spaces around them.
This national study shows that exposure to green space may support cognitive health. Furthermore, the findings support the need for further research on the use of green space exposure as a potential method to reduce the risk of cognitive decline and dementia in older adults.
This research was supported in part by an NIA grant 1K99AG066949-02, R01AG067497, and R01AG065359.
These activities areNIH AD+ADRD Research Implementation Milestone 2.H, “We will continue to support interdisciplinary research to discover and understand disease mechanisms common to Alzheimer’s disease and other neurodegenerative diseases, including rare diseases, and leverage these for therapeutic development. “
Jimenez MP et al. Residential green space and cognitive function in a large cohort of middle-aged women. JAMA network open2022;5(4):e229306. Doi: 10.1001/jamanetworkopen.2022.9306.