Associations of Residential Brownness and Greenness with Fasting Glucose in Young Healthy Adults Living in the Desert.

Hector A Olvera-Alvarez,Matthew H E M Browning,Gregory N Bratman,Andreas M Neophytou

doi:10.3390/ijerph18020520

Abstract

Evolutionary psychology theories propose that contact with green, natural environments may benefit physical health, but little comparable evidence exists for brown, natural environments, such as the desert. In this study, we examined the association between “brownness” and “greenness” with fasting glucose among young residents of El Paso, Texas. We defined brownness as the surface not covered by vegetation or impervious land within Euclidian buffers around participants’ homes. Fasting glucose along with demographic and behavioral data were obtained from the Nurse Engagement and Wellness Study (n = 517). We found that residential proximity to brownness was not associated with fasting glucose when modeled independently. In contrast, we found that residential greenness was associated with decreased levels of fasting glucose, despite the relatively low levels of greenness within the predominantly desert environment of El Paso. A difference between the top and bottom greenness exposure quartiles within a 250 m buffer was associated with a 3.5 mg/dL decrease in fasting glucose levels (95% confidence interval: −6.2, −0.8). Our results suggest that within the understudied context of the desert, green vegetation may be health promoting to a degree that is similar to other, non-desert locations in the world that have higher baselines levels of green.

Highlights

Despite an unprecedented rate of global urbanization in recent decades, human evolution has primarily occurred in natural environments [1,2,3,4]
The Nurse Engagement and Wellness Study (NEWS) consists of a prospective cohort of 517 women and men between 18 and 55 years of age enrolled during the first semester of the Bachelor of Science in Nursing (BSN) program at the University of Texas at El Paso
In contrast to what the biophilia hypothesis and traditional theories from evolutionary psychology might predict, we did not observe a negative association of residential brownness with fasting glucose in a cohort of young adults living in the desert region of El Paso, Texas

Summary

Introduction

Despite an unprecedented rate of global urbanization in recent decades, human evolution has primarily occurred in natural environments [1,2,3,4]. A mounting body of evidence shows that exposure to elements of these natural environments (e.g., trees, vegetation, lakes, and oceans) contributes to human health and well-being [5,6,7,8]. Exposure to blueness (i.e., lakes, rivers, sea) has been linked to mental health and well-being [28,29,30,31,32,33,34] Rare in this field are studies that examine the impact of “brownness” (i.e., elements of the desert environment) on health—despite the fact that these natural landscapes represent more than 35% of Earth’s land cover and are home to over 20% of the global population [35].

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Discussion

Conclusion