In a new study spanning 18 countries, scientists have discovered a compelling link between living on greener streets and improved sleep quality. The findings have been published in the journal Environmental Research.
With sleep deprivation being a significant public health issue, linked to numerous health problems such as obesity, cognitive impairments, and mental health issues, understanding its determinants is crucial. While factors like urban or rural living conditions and neighborhood quality have been studied, the role of natural surroundings, especially the type and extent of greenery around homes, has remained less explored.
The study leveraged data from the BlueHealth International Survey, which gathered responses from 18,838 adults across 18 diverse countries. This comprehensive survey collected responses from 18,838 adults, representing a broad demographic cross-section of the global population. The study honed in on a subset of 16,077 participants for whom complete data on key variables—sleep duration, types of nature exposure, mental well-being, and physical activity—were available.
To capture the multifaceted nature of environmental exposure, the study assessed six distinct types of nature interactions. These ranged from subjective perceptions of local streetscape greenery and views of blue spaces from one’s home to more objective measures like the presence of green space within a 1-kilometer radius and proximity to the coast.
Both perceived streetscape greenery and having a view of blue spaces from home were associated with higher mental well-being. This improved mental well-being, in turn, predicted lower rates of insufficient sleep, defined as less than 6 hours per night. The association between streetscape greenery and better sleep was particularly strong, with mental well-being serving as a partial mediator, suggesting that the psychological benefits derived from viewing greenery directly contribute to this effect.
Although having a blue view from home did not show a significant direct impact on sleep, the indirect effects through mental well-being indicate that such views can still play a valuable role in promoting better sleep patterns.
Lead author Leanne Martin from the University of Exeter’s European Centre for Environment and Human Health said: “People that lived in greener streets reported better mental health, which was the driving factor behind getting a better night’s sleep. Streetscape greening initiatives already exist in urban cities to tackle environmental risks like flooding and heat island effects, but our findings suggest policymakers should extend that to residential areas to support public health by promoting healthier sleep habits.”
Overall, results found 17 percent of people who lived on green streets reported getting fewer than six hours sleep a night, compared to 22 percent of those who did not live on green streets.
Co-author Mathew White, from the University of Vienna, explained: “Whilst a five percent difference may seem small, these findings are comparable to the difference in sleep between people who are coping on their present income and those under financial strain. With money worries widely recognized as an important determinant of sleep, we think this demonstrates street greenness should be recognised by governments as an important public health issue.”
The study also explored the effects of visiting green and blue spaces, finding that frequent visits to these areas were linked to both higher levels of physical activity and better mental well-being. However, when it came to sleep, only the pathways through mental well-being were significant, highlighting the importance of psychological health in the nature-sleep relationship.
Despite its extensive scope, the study acknowledges limitations, such as its cross-sectional design and reliance on self-reported data, which could affect the ability to draw causal inferences. Furthermore, variations in the impact of natural environments on sleep across different countries suggest cultural and environmental differences that future research needs to explore.
This research paves the way for further studies to explore the nuanced relationship between nature exposure and sleep quality, including longitudinal studies and investigations into other potential mediators. It also raises questions about how urban planning and public policies could harness the power of green and blue spaces to improve public health.
“The current study provides evidence that nature visible from home (streetscape greenery, blue views) and recreational visits to green and blue spaces were independently associated with lower rates of insufficient sleep,” the researchers concluded. “These associations were mediated, to varying degrees, by better mental wellbeing.”
“If further evidence can corroborate that these associations are causal, then improved provision and maintenance of residential blue and green spaces may offer a viable strategy of improving mental wellbeing and promoting healthier sleep duration at the population-level. Further, more targeted nature-based interventions may be an appropriate strategy to assist people who are most affected by insufficient sleep.”
The study, “Mechanisms underlying the associations between different types of nature exposure and sleep duration: An 18-country analysis,” was authored by Leanne Martin, Mathew P. White, Lewis R. Elliott, James Grellier, Thomas Astell-Burt, Gregory N. Bratman, Maria L. Lima, Mark Nieuwenhuijsen, Ann Ojala, Anne Roiko, Matilda van den Bosch, and Lora E. Fleming.
