Research has shown the importance of a plant heavy green environment in create positive public health outcomes.
While previous research has linked exposure to greenery with better cognitive functioning, a new study involved a larger participant group and longer observation period than past analyses. It is also the first to examine how different environmental features affect the relationship between greenery and cognition in APOE-ɛ4 carriers.
A new study, published in Environmental Health Perspectives, highlights how living near greenery, such as parks and trees, during middle age can benefit cognitive health later in life. The study discovered that residing in greener areas during midlife could slow cognitive decline by approximately eight months. This effect was even more significant in low socioeconomic status and densely populated neighborhoods.
The study also found that individuals with the APOE-ɛ4 gene, a significant risk factor for Alzheimer’s disease, experienced a threefold reduction in cognitive decline when exposed to more greenery compared to those without the gene.
The researchers analyzed data from the Nurses’ Health Study (NHS). They focused on 16,962 nurses aged 70 or older who participated in a substudy from 1995 to 2008. Cognitive function was assessed through telephone surveys, and satellite imagery was used to measure greenery around participants’ residences. The researchers evaluated greenery exposure up to nine years before the first cognitive test, with assessments including five cognitive tests administered up to four times over an average of six years.
After adjusting for age and socioeconomic factors, higher exposure to greenery during midlife was linked to better cognitive function and slower cognitive decline. This association was stronger for participants of low socioeconomic status and densely populated neighborhoods, suggesting that increasing greenery in disadvantaged areas could help reduce health inequities..
The study underscores the important of greenery in urban and suburban development as well as policies to preserve green spaces and advocates against removing these kinds of spaces for the sake of public health. It is important that we continue to plant trees and create and preserve forests and other green spaces as well as improving our urban centers with more plant life. Such practices can help address certain inequities, too.
MP Jimenez et al. Midlife Residential Greenness and Late-Life Cognitive Decline among Nurses’ Health Study Participants. Environmental Health Perspectives (2024). https://doi.org/10.1289/EHP13588
