Effects of freshwater blue spaces may be beneficial for mental health: A first, ecological study in the North American Great Lakes region

Abstract

Research linking green space and mental health abounds. It also appears that oceanic blue spaces may be salutogenic, benefitting mental health through their expansive viewscapes, and possibly auditory and olfactory stimuli. Yet, it is unknown whether the same is true for freshwater bodies. In this ecological study, we explored associations between hospitalizations for anxiety/mood disorder in Michigan (>30,000) and proximity to the North American Great Lakes. As a sensitivity analysis, we examined associations for 15 different inland lake sizes. Results showed small, protective effects for distance to Great Lake (β = 0.06, p <0.001) and percentage of inland lakes (β = -0.04, p = 0.004). Unexpectedly, shorter distance to nearest inland lake was associated with higher anxiety/mood disorder hospitalizations. The protective effects of percentage area covered by inland lakes was observed for all lake sizes. These initial findings provide a foundation for future individual-level research with finer measurement of health outcomes and blue space exposure.

Mechanisms of Impact of Blue Spaces on Human Health: A Systematic Literature Review and Meta-Analysis

“…Among the 50 articles included in this review, 35 articles had a cross-sectional design [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ], four were cross-over studies [ 66 , 67 , 68 , 69 ], seven were of longitudinal design [ 70 , 71 , 72 , 73 , 74 , 75 , 76 ], two were cohort studies [ 77 , 78 ], one article had both a longitudinal and cross-sectional design [ 79 ] and one article had both a cross-over and cross-sectional design [ 28 ] ( Table 1 ). For physical activity, 14 articles were cross-sectional […”

“…For physical activity, 14 articles were cross-sectional [ 28 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 55 , 56 , 57 , 58 , 59 ], one longitudinal [ 70 ], two cohort studies [ 77 , 78 ] and one both cross-over and cross-sectional [ 28 ]. For restoration, 14 articles were cross-sectional [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 55 , 56 , 57 , 60 , 61 , 62 , 63 ], three were longitudinal [ 71 , 72 , 75 ], three were cross-over [ 66 , 67 , 69 ] and one study had both a longitudinal and cross-sectional design [ 79 ]. For social interaction, six articles were of cross-sectional design [ 43 , 46 , 47 , 56 , 57 , 61 ] and one article was longitudinal [ 73 ].…”

“…The association between exposure to blue spaces and restoration was explored in 21 articles [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 55 , 56 , 57 , 60 , 61 , 62 , 63 , 66 , 67 , 69 , 71 , 72 , 75 , 79 ]. 18 articles reported statistically significant effects of blue spaces on restoration [ 40 , 41 , 42 , 44 , 45 , 55 , 56 , 60 , 61 , 62 , 63 , 66 , 67 , 69 , 71 , 72 , 75 , 79 ], while three articles [ 39 , 43 , 57 ] did not find an association. Living closer to blue space or in an area with more blue space or more blue space surface was generally reported to positively influence restoration compared to living further away or in an area with less blue space or blue space surface, in adult populations.…”

“…More specifically, seven studies found a beneficial effect of blue space availability or visibility on stress or psychological distress [ 41 , 43 , 55 , 56 , 63 , 66 , 71 ], while four articles used mental or emotional wellbeing as a restoration indicator and also found a beneficial effect [ 40 , 60 , 66 , 71 ]. Positive effects of blue space availability or visibility on anxiety or mood disorders were reported in one study [ 42 ]. Pearson et al [ 42 ] suggested that proximity to Great Lakes had a positive effect on mood disorders but proximity to inland lakes had a negative effect.…”

Introduction

“…The chapter on the blue mind explores this concept and reports on the research that supports it. The mere act of providing good stewardship of our ocean ecosystems seems to play an important role in this benefit [7].…”