The association between natural outdoor environments and common somatic symptoms

There is growing evidence that urban natural outdoor environments (NOE) may positively impact health by reducing stress and stress-related symptoms. However, there is limited research investigating this link across a range of NOE indicators. This cross-sectional study investigated the association between neighbourhood NOE (availability, use, and satisfaction with NOE) and common somatic symptoms and the role of potential mediators. Data were analysed from 3481 adults from Barcelona (Spain), Doetinchem (Netherlands), Kaunas (Lithuania) and Stoke-on-Trent (United Kingdom). NOE data were obtained through self-reported data and environmental measurements. Common somatic symptom data were self-reported. Mixed effects regression models were used for analysis, with models adjusted for potential sociodemographic confounders. Higher satisfaction with neighbourhood NOE was associated with lower prevalence of common somatic symptoms (exp(β) 0.97; 95% CI 0.96, 0.98); an association partially mediated by mental health, social cohesion and air quality concern. A longer time spent in NOE was associated with lower prevalence of common somatic symptoms in low socioeconomic status neighbourhoods (exp(β) 0.98; 95% CI 0.96, 1.00). A higher number of neighbourhood green spaces (300m buffer) was associated with higher prevalence of common somatic symptoms (exp(β) 1.03; 95% CI 1.00, 1.05). No statistically significant associations were found for other NOE indicators. Study findings suggest that higher satisfaction with NOE may be associated with lower prevalence of common somatic symptoms, with mental health, social cohesion and concern about air quality playing partial mediating roles. Little evidence was found of an association between objective NOE measurements and common somatic symptoms, underlining the importance of perceptions of NOE for conferring health benefits.