Exposure to green spaces may improve cognitive health
According to an NIA-funded study, residential areas with more green space were associated with faster thinking, better attention, and higher overall cognitive function in middle-aged women. Posted in Opening of the JAMA network, the results suggest that green spaces – such as trees, flowers, grass, gardens and parks – could be explored as a potential community approach to improving cognitive health.
For this study, a team of researchers from Boston University, Harvard University, and the Alzheimer’s Disease Center at Rush University in Chicago analyzed data from cognitive testing and residential green spaces in 13,594 women aged 61 on average. The women were enrolled in the Nurses’ Health Study II, a longitudinal study that examines risk factors for major chronic diseases in women. Participants took online cognitive tests that measured psychomotor speed, attention, learning and working memory. Then, using satellite image-based technology, the researchers determined the amount of green space around each participant’s home. The researchers assessed the association between the amount of green space within walking distance of a participant’s home and their cognitive function.
They found that women living in areas with more green space had higher scores in thinking speed, attention and overall cognitive function. From a cognitive point of view, this translates to 1.2 years younger. However, living in an area with more green space did not affect learning or working memory, which involves keeping track of information while performing a task. This finding is consistent with another study that found living in neighborhoods with green spaces was not associated with the size of the hippocampus, a part of the brain responsible for memory and learning.
Next, the team tested several factors believed to affect cognition, including neighborhood socioeconomic status (SES). Notably, among women living in higher SES neighborhoods, the positive association between green spaces and speed of thinking and attention, as well as overall cognitive function, was higher. They also found that the effects of green spaces on cognition were not significantly affected by population density. This suggests that the cognitive benefits of green spaces extend to diverse contexts, such as urban neighborhoods.
Previous research has shown that green spaces are associated with lower pollution levels, lower risk of depression, and increased physical activity, which may have a positive effect on cognition. In this study, researchers found that the positive impact of green spaces on thinking speed, attention, and overall cognitive function could not be explained by air quality or activity effects. physical. However, they found that the cognitive benefit of living near green space may be partly due to reduced rates of depression. This explanation is supported by previous findings that higher exposure to green spaces is associated with a lower risk of depression. Given that depression is a risk factor for dementia, these findings also suggest that using green space may help reduce dementia risk.
As the authors noted, most participants were white; thus, further research is needed to understand how racial disparities and socioeconomic factors affect the association between green spaces and cognitive function. They also noted that future studies should examine how people interact with the green spaces around them.
This national study shows that exposure to green spaces can promote cognitive health. Additionally, the results support the need for further research into the use of exposure to green space as a possible way to reduce the risk of cognitive decline and dementia in older adults.
This research was supported in part by grants from the NIA 1K99AG066949-02, R01AG067497 and R01AG065359.
These activities concernNIH AD+SARD Research Implementation Stage 2.H, “Continue to support interdisciplinary research to discover and understand the disease mechanisms that are common between Alzheimer’s disease and other neurodegenerative disorders, including rare disorders, and exploit them for the development of therapies.
Jiménez MP, et al. Residential green space and cognitive function in a large cohort of middle-aged women. Open JAMA Network. 2022;5(4):e229306. doi: 10.1001/jamanetworkopen.2022.9306.