Slower epigenetic (biological) aging is associated with exposure to green space, according to researchers based at Northwestern University.

According to the study results, people who lived near more green spaces were biologically 2.5 years younger, on average, than those who live near less greenness. The study’s 924 participants with a mean age of 45.3 years consisted of 376 Black and 548 white participants where 453 were men and 471 were women. Five hundred and four (54.5%) participants had parks within 5 km of their residential address.

Study participants reside in four cities across the U.S.: Birmingham, Ala.; Chicago; Minneapolis; and Oakland, Calif. This sample represents a subset of a larger-scale cohort study conducted in the U.S., the Coronary Artery Risk Development in Young Adults (CARDIA).

Black participants tended to have less surrounding green space compared to the white participants, and beneficial association of greenness with epigenetic aging was only found among white participants, according to the research. The study’s sex-stratified analyses exhibited protective associations of greenness in women but not in men.

While researchers acknowledge that additional study is needed, the results help make the case for age- and dementia friendly community stakeholders to consider how to add, improve, or activate green spaces to support healthy aging.