Association between greenspace and cancer: evidence from a systematic review and meta-analysis of multiple large cohort studies

Neighborhood socioeconomic disparities in cancer incidence following a hypothetical intervention to increase residential greenspace cover in the UK Biobank cohort

BACKGROUND

Higher greenspace exposure has been associated with lower risk of certain cancers. However, few studies have evaluated potential benefits of increasing population-level exposure to greenspace on cancer disparities. We estimated the impact of a hypothetical intervention to increase residential greenspace cover on neighborhood socioeconomic disparities in total, breast, colorectal, lung, and prostate cancer incidence.

METHODS

Our study included 411,787 cancer-free UK Biobank participants. Percentage of greenspace around baseline residential addresses (300m, 1000m distance buffers) was derived by combining domestic gardens and greenspace cover from the Generalized Land Use Database. We categorized neighborhood socioeconomic deprivation using the Index of Multiple Deprivation (2010). We estimated hazard ratios (HR) and 95% confidence intervals (CI) of each cancer associated with greenspace, adjusting for sociodemographic and lifestyle factors. We additionally adjusted for air pollution in supplementary analyses as we a-priori hypothesized that it was on the causal pathway between greenspace and cancer. Further, we used parametric g-computation to calculate the standardized 10-year risk of each cancer, comparing the least to most socioeconomically disadvantaged participants, both without any hypothetical greenspace intervention and under a hypothetical intervention to increase residential greenspace cover to a favorable threshold (75th percentile amongst the least socioeconomically deprived participants).

RESULTS

We documented 40,519 incident cases of cancer over 4,210,008 person-years follow-up. An interquartile range increase in greenspace cover within 300m was associated with lower incidence of total (HR 0.98; 95% CI 0.97, 1.00) and lung (HR 0.96; 95% CI 0.92, 0.99) cancer, and was suggestively associated with lower prostate and breast cancer incidence, but not colorectal cancer. Additional adjustment for fine particulate matter air pollution (PM2.5) weakened lung cancer associations but strengthened breast and prostate cancer associations (e.g., greenspace 1000m breast cancer HR 0.94; 95% CI 0.89 0.99; 1000m prostate cancer HR 0.91; 95% CI 0.86, 0.95). The hypothetical intervention to increase greenspace (300m) resulted in 1.3 fewer total cancer cases per 1000 (95% CI 1.0, 1.6) in the most compared to least deprived group, a 23% reduction in the socioeconomic disparity gap.

DISCUSSION

Higher residential greenspace cover was associated with lower total and lung cancer incidence, and suggestively associated with lower breast and prostate cancer incidence. Policies to increase residential greenspace cover may reduce the risk of certain cancers, particularly among socioeconomically disadvantaged groups.

Urology on a changing planet: links between climate change and urological disease

Urological diseases and their varied forms of management warrant special attention in the setting of climate change. Regarding urological cancers, climate change will probably increase the incidence and severity of cancer diagnoses through exposures to certain environmental risk factors, while simultaneously disrupting cancer care delivery and downstream outcomes. Regarding benign urological diseases, a burgeoning body of work exists on climate-related heat waves, dehydration, urolithiasis, renal injury and infectious and vector-borne diseases. Adding to the potential effect on disease pathogenesis, many patients with urological diseases undergo high-tech, resource-intensive interventions, such as robotic surgery, and entail intensive longitudinal assessments over many years. These features incur a considerable carbon footprint, generate substantial waste, and can introduce vulnerabilities to climate-related weather events. Links exist between planetary health (the health of humans and the natural systems that support our health), climate change and urological disease and urological care providers face many challenges in the era of anthropogenic climate change. The next steps and priorities for research, management, and health care delivery include identification and prioritization of health care delivery strategies to minimize waste and carbon emissions, while supporting climate resilience. Examples include supporting telemedicine, limiting low-value care, and building resilience to minimize impacts of climate-related disasters to prepare for the challenges ahead.

Neighborhood greenness and long-term physical and psychosocial quality of life among prostate cancer survivors in the Health Professionals Follow-up Study

INTRODUCTION

Neighborhood greenness may benefit long-term prostate cancer survivorship by promoting physical activity and social integration, and reducing stress and exposure to air pollution, noise, and extreme temperatures. We examined associations of neighborhood greenness and long-term physical and psychosocial quality of life in prostate cancer survivors in the Health Professionals Follow-up Study.

METHODS

We included 1437 individuals diagnosed with non-metastatic prostate cancer between 2008 and 2016 across the United States. Neighborhood greenness within a 1230m buffer of each individual's mailing address was measured using the Landsat satellite image-based Normalized Difference Vegetation Index (NDVI). We fit generalized linear mixed effect models to assess associations of greenness (in quintiles) with longitudinal patient reported outcome measures on prostate cancer-specific physical and psychosocial quality of life, adjusting for time-varying individual- and neighborhood-level demographic factors and clinical factors.

RESULTS

The greatest symptom burden was in the sexual domain. More than half of survivors reported good memory function and the lack of depressive signs at diagnosis. In fully adjusted models, cumulative average greenness since diagnosis was associated with fewer vitality/hormonal symptoms (highest quintile, Q5, vs lowest quintile, Q1: mean difference: 0.46, 95% confidence interval [CI]: 0.81, -0.12). Other domains of physical quality of life (bowel symptoms, urinary incontinence, urinary irritation, and sexual symptoms) did not differ by greenness overall. Psychosocial quality of life did not differ by greenness overall (Q5 vs Q1, odds ratio [95% CI]: memory function: 1.01 [0.61, 1.73]; lack of depressive signs: 1.10 [0.63, 1.95]; and wellbeing: 1.17 [0.71, 1.91]).

CONCLUSION

During long-term prostate cancer survivorship, cumulative average 1230m greenness since diagnosis was associated with fewer vitality/hormonal symptoms. Other domains of physical quality of life and psychosocial quality of life did not differ by greenness overall. Limitations included potential non-differential exposure measurement error and NDVI's lack of time-activity pattern.

The Effects of Green Spaces and Noise Exposure on the Risk of Ischemic Stroke: A Case-Control Study in Lebanon

BACKGROUND

Environmental surroundings reduce the rate of several diseases, especially those related to stressful events. Ischemic stroke can be affected by such events, either directly or through its risk factors. Therefore, the present study evaluates the effects of green spaces and noise exposure on the risk of ischemic stroke.

METHODS

A case-control study was carried out, including 200 ischemic stroke cases within the first 48 h of diagnosis and 200 controls, divided equally into hospitalized and non-hospitalized participants. Controls were matched to cases based on age and gender. Socio-demographic characteristics were assessed, in addition to environmental surroundings and noise exposure at home and at workplaces.

RESULTS

Living in a house, having a house garden, and taking care of the garden were associated with a lower risk of suffering an ischemic stroke (p < 0.001, p < 0.001, and p = 0.009, respectively). However, having buildings as the view from home led to a higher stroke rate (p < 0.001). Working in an urban area, the workplace being surrounded by buildings, and the workplace not being surrounded by green spaces were also associated with a higher risk of suffering an ischemic stroke (p = 0.002, p = 0.001, and p = 0.03, respectively). As for noise exposure, being exposed to traffic noise, human noise, and other types of noise was significantly associated with a higher risk of ischemic stroke, while being exposed to higher levels of natural noise was significantly associated with a lower risk of ischemic stroke. Higher levels of noise were also associated with higher risks of ischemic stroke in homes and workplaces (p < 0.001 and p = 0.008, respectively).

CONCLUSIONS

Environmental surroundings and noise exposure were found to affect the risk of ischemic stroke. Greater green spaces and lower noise exposure play a protective role against ischemic stroke, suggesting a possible prevention strategy through environmental modifications at home and workplaces.

Different types of greenspace within urban parks and depressive symptoms among older U.S. adults living in urban areas

Access to greenspace in the form of urban parks is frequently used to study the mental health benefits of nature and may alleviate depression. However, there is a lack of research that considers the different types of vegetated and non-vegetated spaces that parks can provide. Our aim was to investigate whether different types of accessible park area, grassy; tree covered; and non-vegetated, were associated with depressive symptoms among older (≥50 years) urban US adults. We used interviews from the Health and Retirement Study spanning 2010 through 2016 as our primary data source. We calculated total grassy, tree covered, and non-vegetated park space accessible to participants using a comprehensive national database of US parks and a high resolution (10 m) landcover dataset. To measure depressive symptoms, we used the CESD-8 analyzed as a continuous scale. We used Poisson regression to estimate the percent difference in CESD-8 scores comparing quartiles of accessible park space. To control for confounding, we adjusted for sociodemographic characteristics, geography, and climate. Aggregated accessible park area was not substantively associated with depressive symptoms. However, having grassy park area near the home was associated with as much as 27 % fewer depressive symptoms. In contrast, non-vegetated park area was associated with up to 54 % more depressive symptoms. Our findings were robust to adjustment for air pollution, environmental noise, and artificial light at night. Different types of accessible park space may have disparate effects on mental health among older urban US adults.

Credibility of the evidence on green space and human health: an overview of meta-analyses using evidence grading approaches

BACKGROUND

Green space is an important part of the human living environment, with many epidemiological studies estimating its impact on human health. However, no study has quantitatively assessed the credibility of the existing evidence, impeding their translations into policy decisions and hindering researchers from identifying new research gaps. This overview aims to evaluate and rank such evidence credibility.

METHODS

Following the PRISMA guideline, we systematically searched PubMed, Web of Science, and Embase databases for systematic reviews with meta-analyses concerning green spaces and health outcomes published up to January 15, 2024. We categorized the credibility of meta-analytical evidence from interventional studies into four levels (i.e., high, moderate, low, and very low) using the Grading of Recommendation, Assessment, Development and Evaluations framework, based on five domains including risk of bias, inconsistency, indirectness, imprecision, and publication bias. Further, we recalculated all the meta-analyses from observational studies and classified evidence into five levels (i.e., convincing, highly suggestive, suggestive, weak, and non-significant) by considering stringent thresholds for P-values, sample size, robustness, heterogeneity, and testing for biases.

FINDINGS

In total, 154 meta-analysed associations (interventional = 44, observational = 110) between green spaces and health outcomes were graded. Among meta-analyses from interventional studies, zero, four (wellbeing, systolic blood pressure, negative affect, and positive affect), 20, and 20 associations between green spaces and health outcomes were graded as high, moderate, low, and very low credibility evidence, respectively. Among meta-analyses from observational studies, one (cardiovascular disease mortality), four (prevalence/incidence of diabetes mellitus, preterm birth, and small for gestational age infant, and all-cause mortality), 12, 22, and 71 associations were categorized as convincing, highly suggestive, suggestive, weak, and non-significant evidence, respectively.

INTERPRETATION

The current evidence largely confirms beneficial associations between green spaces and human health. However, only a small subset of these associations can be deemed to have a high or convincing credibility. Hence, future better designed primary studies and meta-analyses are still needed to provide higher quality evidence for informing health promotion strategies.

FUNDING

The National Natural Science Foundation of China of China; the Guangzhou Science and Technology Program; the Guangdong Medical Science and Technology Research Fund; the Research Grant Council of the Hong Kong SAR; and Sino-German mobility program.

Risk factors for prostate cancer: An umbrella review of prospective observational studies and mendelian randomization analyses

BACKGROUND

The incidence of prostate cancer is increasing in older males globally. Age, ethnicity, and family history are identified as the well-known risk factors for prostate cancer, but few modifiable factors have been firmly established. The objective of this study was to identify and evaluate various factors modifying the risk of prostate cancer reported in meta-analyses of prospective observational studies and mendelian randomization (MR) analyses.

METHODS AND FINDINGS

We searched PubMed, Embase, and Web of Science from the inception to January 10, 2022, updated on September 9, 2023, to identify meta-analyses and MR studies on prostate cancer. Eligibility criteria for meta-analyses were (1) meta-analyses including prospective observational studies or studies that declared outcome-free at baseline; (2) evaluating the factors of any category associated with prostate cancer incidence; and (3) providing effect estimates for further data synthesis. Similar criteria were applied to MR studies. Meta-analysis was repeated using the random-effects inverse-variance model with DerSimonian-Laird method. Quality assessment was then conducted for included meta-analyses using AMSTAR-2 tool and for MR studies using STROBE-MR and assumption evaluation. Subsequent evidence grading criteria for significant associations in meta-analyses contained sample size, P values and 95% confidence intervals, 95% prediction intervals, heterogeneity, and publication bias, assigning 4 evidence grades (convincing, highly suggestive, suggestive, or weak). Significant associations in MR studies were graded as robust, probable, suggestive, or insufficient considering P values and concordance of effect directions. Finally, 92 selected from 411 meta-analyses and 64 selected from 118 MR studies were included after excluding the overlapping and outdated studies which were published earlier and contained fewer participants or fewer instrument variables for the same exposure. In total, 123 observational associations (45 significant and 78 null) and 145 causal associations (55 significant and 90 null) were categorized into lifestyle; diet and nutrition; anthropometric indices; biomarkers; clinical variables, diseases, and treatments; and environmental factors. Concerning evidence grading on significant associations, there were 5 highly suggestive, 36 suggestive, and 4 weak associations in meta-analyses, and 10 robust, 24 probable, 4 suggestive, and 17 insufficient causal associations in MR studies. Twenty-six overlapping factors between meta-analyses and MR studies were identified, with consistent significant effects found for physical activity (PA) (occupational PA in meta: OR = 0.87, 95% CI: 0.80, 0.94; accelerator-measured PA in MR: OR = 0.49, 95% CI: 0.33, 0.72), height (meta: OR = 1.09, 95% CI: 1.06, 1.12; MR: OR = 1.07, 95% CI: 1.01, 1.15, for aggressive prostate cancer), and smoking (current smoking in meta: OR = 0.74, 95% CI: 0.68, 0.80; smoking initiation in MR: OR = 0.91, 95% CI: 0.86, 0.97). Methodological limitation is that the evidence grading criteria could be expanded by considering more indices.

CONCLUSIONS

In this large-scale study, we summarized the associations of various factors with prostate cancer risk and provided comparisons between observational associations by meta-analysis and genetically estimated causality by MR analyses. In the absence of convincing overlapping evidence based on the existing literature, no robust associations were identified, but some effects were observed for height, physical activity, and smoking.