Greenspace, Inflammation, Cardiovascular Health, and Cancer: A Review and Conceptual Framework for Greenspace in Cardio-Oncology Research

Engagement with nature and proinflammatory biology

BACKGROUND

Prior evidence indicates that contact with nature improves physical health, but data explicitly linking engagement with nature to biological processes are limited.

DESIGN

Leveraging survey and biomarker data from 1,244 adults (mean age = 54.50 years, range = 34-84 years) from the Midlife in the United States (MIDUS II) study, we examined associations between nature engagement, operationalized as the frequency of pleasant nature encounters, and systemic inflammation. Concentrations of interleukin-6 (IL-6), C-reactive protein (CRP), and fibrinogen were measured from fasting blood samples. Analyses adjusted for sociodemographic, health behavior, and psychological well-being covariates.

RESULTS

More frequent positive nature contact was independently associated with lower circulating levels of inflammation.

CONCLUSIONS

These findings add to a growing literature on the salubrious health effects of nature by demonstrating how such experiences are instantiated in downstream physiological systems, potentially informing future interventions and public health policies.

Multilevel Characteristics of Cumulative Symptom Burden in Young Survivors of Childhood Cancer

Importance

Symptom burden and its characteristics among survivors of pediatric cancers aged 8 to 18 years remain understudied.

Objective

To examine the prevalence of symptom burden among young childhood cancer survivors and identify associations with sociodemographic, clinical, and psychological resilience skills, and health-related quality of life (HRQOL).

Design, Setting, and Participants

A cross-sectional analysis using data collected from November 1, 2017, to January 31, 2019, in a survivorship clinic at a US-based comprehensive cancer center was conducted. Participants included 302 dyads of children aged 8 to 18 years who survived at least 5 years beyond diagnosis and their primary caregivers. Data analysis was performed from March 13, 2023, to February 29, 2024.

Exposures

Diagnosis, caregiver-reported family conflict, self-reported caregiver anxiety, neighborhood-level social vulnerability, and survivor-reported meaning and purpose.

Main Outcomes and Measures

Novel symptom-level burden, integrating the attributes of severity and daily activity interference using the pediatric version of the Patient-Reported Outcomes Version of the Common Terminology Criteria for Adverse Events, global cumulative symptom burden, and HRQOL using the EuroQol-5D. Multinomial logistic regression identified characteristics associated with symptom burden; linear regression assessed symptom burden and HRQOL associations.

Results

Among 302 survivors (mean [SD] age, 14.2 [2.9] years, mean [SD] time since diagnosis, 10.9 [2.9] years; 153 [50.7%] male), 186 (62.0%) had low, 77 (25.7%) moderate, and 37 (12.3%) high global cumulative symptom burden. Greater caregiver anxiety was associated with moderate (risk ratio [RR], 1.56; 95% CI, 1.09-2.24) global symptom burden. Greater neighborhood deprivation was associated with moderate global symptom burden (RR, 4.86; 95% CI, 1.29-18.26). Survivors with greater meaning/purpose were less likely to have moderate (RR, 0.42; 95% CI, 0.29-0.61) and high (RR, 0.27; 95% CI, 0.16-0.46) global symptom burden. The burden of individual symptoms displayed similar patterns. Low (Cohen d, -0.60; 95% CI, -0.87 to -0.32) and moderate/high (d, -0.98; 95% CI, -1.53 to -0.43) general pain, moderate/high numbness (d, -0.99; 95% CI, -1.69 to -0.29), and moderate/high worry (d, -0.55; 95% CI, -0.99 to -0.11) were associated with lower HRQOL.

Conclusions and Relevance

In this cross-sectional study of young childhood cancer survivors, symptom burden was prevalent. Caregiver anxiety and disparity-related neighborhood factors were associated with greater symptom burden, whereas meaning and purpose was a protective factor. Greater specific symptom burden contributed to poorer HRQOL. The findings suggest that interventions targeting resilience and neighborhood adversity may alleviate symptom burden and improve HRQOL.

Disparities in Cardiovascular Disease-Related Outcomes Among Cancer Survivors in the United States: A Systematic Review of the Literature

BACKGROUND

Cancer and cardiovascular disease (CVD) are major causes of morbidity and mortality in the United States (US). Cancer survivors have increased risks for CVD and CVD-related mortality due to multiple factors including cancer treatment-related cardiotoxicity. Disparities are rooted in differential exposure to risk factors and social determinants of health (SDOH), including systemic racism. This review aimed to assess SDOH's role in disparities, document CVD-related disparities among US cancer survivors, and identify literature gaps for future research.

METHODS

Following the Peer Review of Electronic Search Strategies (PRESS) guidelines, MEDLINE, PsycINFO, and Scopus were searched on March 15, 2021, with an update conducted on September 26, 2023. Articles screening was performed using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2020, a pre-defined Population, Exposure, Comparison, Outcomes, and Settings (PECOS) framework, and the Rayyan platform. A modified version of the Newcastle-Ottawa Scale was used to assess the risk of bias, and RAW Graphs for alluvial charts. This review is registered with PROSPERO under ID #CRD42021236460.

RESULTS

Out of 7,719 retrieved articles, 24 were included, and discussed diverse SDOH that contribute to CVD-related disparities among cancer survivors. The 24 included studies had a large combined total sample size (n=7,704,645; median=19,707). While various disparities have been investigated, including rural-urban, sex, socioeconomic status, and age, a notable observation is that non-Hispanic Black cancer survivors experience disproportionately adverse CVD outcomes when compared to non-Hispanic White survivors. This underscores historical racism and discrimination against non-Hispanic Black individuals as fundamental drivers of CVD-related disparities.

CONCLUSIONS

Stakeholders should work to eliminate the root causes of disparities. Clinicians should increase screening for risk factors that exacerbate CVD-related disparities among cancer survivors. Researchers should prioritise the investigation of systemic factors driving disparities in cancer and CVD and develop innovative interventions to mitigate risk in cancer survivors.

Time outdoors and residential greenness are associated with reduced systemic inflammation and allostatic load

Contacts with nature are linked with reduced morbidity and mortality. Hypothesized pathways include relaxation, physical activity, and improved immune function. This cross-sectional study of 320 adults in central North Carolina assessed health benefits of residential greenness using allostatic load (AL) and systemic inflammation (INFL) indices, composite biomarker-based measures of physiological dysregulation and inflammation, respectively. Distance-to-residence weighted tree cover and vegetated land cover measures were estimated within 500 m of each residence; 37 biomarkers of immune, neuroendocrine, cardiovascular, and metabolic functions were dichotomized at distribution or health-based cut-offs. AL was calculated as a sum of potentially unhealthy values of all biomarkers; INFL was based on a subset of 18 immune biomarkers. Regression analysis used generalized additive models for Poisson-distributed outcome. An interquartile range (IQR) increase in tree cover was associated with 0.89 (95 % Confidence Limits 0.82; 0.97) and 0.90 (0.79; 1.03)-fold change in AL and INFL, respectively. Greater daily outdoor time was associated with reduced AL and INFL, while leisure screen time, problems with sleeping, and common chronic infections were linked with increased AL and INFL. Among 138 individuals spending more than 1 h outdoors daily, an IQR increase in tree cover was associated with 0.76 (0.67; 0.86) and 0.81 (0.65; 1.02)-fold changes in AL and INFL, respectively. Among individuals with residential tree cover above the 50th percentile, spending more than 3 h outdoors daily was associated with 0.54 (0.37; 0.78) and 0.28 (0.15; 0.54)-fold changes in AL and INFL, respectively, compared to spending less than 30 min outdoors; there were no significant effects in the low tree cover stratum. Consistent but weaker effects were observed for vegetated land cover. Interaction effects of tree and vegetative cover and time spent outdoors on AL and INFL were statistically significant. This biomarker-based approach can help to assess public health benefits of green spaces.

Forest Bathing Increases Adolescents' Mental Well-Being: A Mixed-Methods Study

Previous research has demonstrated that practicing forest bathing has significant positive effects on adult psychological well-being. Considering the ongoing adolescents' mental health crisis of increasing anxiety and depression, determining whether forest bathing has similar effects on adolescents is an important expansion of forest bathing research. This study investigated the possibility that forest bathing could improve adolescents' mental well-being and sought to determine participants' experiences of forest bathing. It used a convergent, parallel, mixed-methods design that was partially co-created with 24 participants aged 16-18 as part of a youth participatory action research (YPAR) project in which participants practiced forest bathing three times over 3 weeks. As measured using the Warwick-Edinburgh Mental Well-Being Survey, the mean participant mental well-being increased significantly after forest bathing, with moderate to large effect sizes. Participants described reduced stress and increased feelings of relaxation, peace, and happiness. These findings correlate with previous forest bathing research involving adult participants. It is recommended that educators and others who work with adolescents consider forest bathing as a simple, low-cost way to improve adolescents' mental well-being.

The Exposome and Cardiovascular Health

The study of the interplay between social factors, environmental hazards, and health has garnered much attention in recent years. The term "exposome" was coined to describe the total impact of environmental exposures on an individual's health and well-being, serving as a complementary concept to the genome. Studies have shown a strong correlation between the exposome and cardiovascular health, with various components of the exposome having been implicated in the development and progression of cardiovascular disease. These components include the natural and built environment, air pollution, diet, physical activity, and psychosocial stress, among others. This review provides an overview of the relationship between the exposome and cardiovascular health, highlighting the epidemiologic and mechanistic evidence of environmental exposures on cardiovascular disease. The interplay between various environmental components is discussed, and potential avenues for mitigation are identified.

Neighborhood attributes and cardiovascular disease risk in breast cancer survivors: The Pathways Study

BACKGROUND

Breast cancer survivors are at a higher risk of cardiovascular disease (CVD) morbidity and mortality compared with the general population. The impact of objective social and built neighborhood attributes on CVD risk in a cohort of female breast cancer survivors was examined.

METHODS

The 3975 participants came from the Pathways Study, a prospective cohort of women with invasive breast cancer from an integrated health care system in northern California. Women diagnosed with breast cancer from 2006 through 2013 were enrolled on average approximately 2 months after diagnosis. Their baseline addresses were geocoded and appended to neighborhood attributes for racial/ethnic composition, socioeconomic status (SES), population density, urbanization, crime, traffic density, street connectivity, parks, recreational facilities, and retail food environment. Incident CVD events included ischemic heart disease, heart failure, cardiomyopathy, or stroke. Cox proportional hazards models estimated associations of neighborhood attributes with CVD risk, which accounted for clustering by block groups. Fully adjusted models included sociodemographic, clinical, and behavioral factors.

RESULTS

During follow-up through December 31, 2018, 340 participants (8.6%) had CVD events. A neighborhood racial/ethnic composition measure, percent of Asian American/Pacific Islander residents (lowest quintile hazard ratio [HR], 1.85; 95% CI, 1.03-3.33), and crime index (highest quartile HR, 1.48; 95% CI, 1.08-2.03) were associated with the risk of CVD events independent of individual SES, hormone receptor status, treatment, cardiometabolic comorbidities, body mass index, and physical activity.

CONCLUSIONS

With the application of a socio-ecological framework, how residential environments shape health outcomes in women with breast cancer and affect CVD risk in this growing population can be understood.

Historical redlining and breast cancer treatment and survival among older women in the United States

BACKGROUND

Breast cancer (BC) is the most common cancer among US women, and institutional racism is a critical cause of health disparities. We investigated impacts of historical redlining on BC treatment receipt and survival in the United States.

METHODS

Home Owners' Loan Corporation (HOLC) boundaries were used to measure historical redlining. Eligible women in the 2010-2017 Surveillance, Epidemiology, and End Results-Medicare BC cohort were assigned a HOLC grade. The independent variable was a dichotomized HOLC grade: A and B (nonredlined) and C and D (redlined). Outcomes of receipt of various cancer treatments, all-cause mortality (ACM), and BC-specific mortality (BCSM) were analyzed using logistic or Cox models. Indirect effects by comorbidity were examined.

RESULTS

Among 18 119 women, 65.7% resided in historically redlined areas (HRAs), and 32.6% were deceased at a median follow-up of 58 months. A larger proportion of deceased women resided in HRAs (34.5% vs 30.0%). Of all deceased women, 41.6% died of BC; a larger proportion resided in HRAs (43.4% vs 37.8%). Historical redlining is a statistically significant predictor of poorer survival after BC diagnosis (hazard ratio = 1.09, 95% confidence interval [CI] = 1.03 to 1.15 for ACM, and hazard ratio = 1.26, 95% CI = 1.13 to 1.41 for BCSM). Indirect effects via comorbidity were identified. Historical redlining was associated with a lower likelihood of receiving surgery (odds ratio = 0.74, 95% CI = 0.66 to 0.83, and a higher likelihood of receiving palliative care odds ratio = 1.41, 95% CI = 1.04 to 1.91).

CONCLUSION

Historical redlining is associated with differential treatment receipt and poorer survival for ACM and BCSM. Relevant stakeholders should consider historical contexts when designing and implementing equity-focused interventions to reduce BC disparities. Clinicians should advocate for healthier neighborhoods while providing care.

Green space exposure and colorectal cancer: A systematic review

Green space has been linked to colorectal cancer, but the evidence is still limited and inconclusive. This review aimed to investigate the relationship between green space and CRC. The studies were searched using three primary journal databases: PubMed, Scopus, and Web of Science. The retrieved citations were screened, and data from articles about GS exposure and CRC were extracted. The Newcastle-Ottawa Quality Assessment Form for Cohort Studies was used to evaluate the studies' quality. Five of the 1792 articles identified were eligible for the final review, which included five cohort studies published between 2017 and 2022. Each one article from the United States, the United Kingdom, France, Belgium, and Germany and All studies are of high quality. Four studies reported CRC incidence and one study reported CRC mortality from GS exposure. There was no significant association between GS attributes (Normalized Difference Vegetation Index (NDVI), surrounding greenness, surrounding green area, proximity to GS (agricultural lands, urban GSs, and forests), and count of recreational facilities and parks) with CRC. Only one study discovered that a healthier ecosystem was linked to a lower CRC risk. Although the evidence is still limited, the findings may indicate the presence of other factors in the relationship between GS and CRC. Future research should continue to focus on the variation of GS and the factors that influence it. Specific attention to the development of GS has the potential to produce benefits while mitigating cancer risk.

Nature-Based Interventions and Exposure among Cancer Survivors: A Scoping Review

BACKGROUND AND PURPOSE

nature-based interventions (NBI) have been shown to have positive effects on physical, psychological, social, and spiritual health. The purpose of this scoping literature review was to describe what is known regarding the cancer survivor experience in relationship to their interaction with the natural environment. Description/methods: this review was completed using the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The research strategy included a combination of these terms: cancer, neoplasms, nature, and forest therapy. The articles were blinded and screened by four independent researchers. A total of twelve articles were selected. Outcome/results: a total of 2786 cancer survivors participated in the twelve studies with multiple types and stages of cancer represented. The studies used multiple designs and measures. Results showed improvements in anxiety, depression, sleep, connectedness, stress, tension, confusion, fatigue, and pain. Participants reported that nature was the most important resource in coping with their cancer.

CONCLUSIONS AND IMPLICATIONS

nature is beneficial for cancer survivors while they experience cancer diagnosis and treatment. Nature opportunities can be feasibly delivered with this population and need to be explored further and safely implemented to support the overall health and well-being of cancer survivors.

The impact of greenspace or nature-based interventions on cardiovascular health or cancer-related outcomes: A systematic review of experimental studies

SIGNIFICANCE

Globally, cardiovascular disease (CVD) and cancer are leading causes of morbidity and mortality. While having different etiologies, CVD and cancer are linked by multiple shared risk factors, the presence of which exacerbate adverse outcomes for individuals with either disease. For both pathologies, factors such as poverty, lack of physical activity (PA), poor dietary intake, and climate change increase risk of adverse outcomes. Prior research has shown that greenspaces and other nature-based interventions (NBIs) contribute to improved health outcomes and climate change resilience.

OBJECTIVE

To summarize evidence on the impact of greenspaces or NBIs on cardiovascular health and/or cancer-related outcomes and identify knowledge gaps to inform future research.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and Peer Review of Electronic Search Strategies (PRESS) guidelines, we searched five databases: Web of Science, Scopus, Medline, PsycINFO and GreenFile. Two blinded reviewers used Rayyan AI and a predefined criteria for article inclusion and exclusion. The risk of bias was assessed using a modified version of the Newcastle-Ottawa Scale (NOS). This review is registered with PROSPERO, ID # CRD42021231619.

RESULTS & DISCUSSION

Of 2565 articles retrieved, 31 articles met the inclusion criteria, and overall had a low risk of bias. 26 articles studied cardiovascular related outcomes and 5 studied cancer-related outcomes. Interventions were coded into 4 categories: forest bathing, green exercise, gardening, and nature viewing. Outcomes included blood pressure (BP), cancer-related quality of life (QoL) and (more infrequently) biomarkers of CVD risk. Descriptions of findings are presented as well as visual presentations of trends across the findings using RAW graphs. Overall studies included have a low risk of bias; and alluvial chart trends indicated that NBIs may have beneficial effects on CVD and cancer-related outcomes.

CONCLUSIONS & IMPLICATIONS

(1) Clinical implication: Healthcare providers should consider the promotion of nature-based programs to improve health outcomes. (2) Policy implication: There is a need for investment in equitable greenspaces to improve health outcomes and build climate resilient neighborhoods. (3) Research or academic implication: Research partnerships with community-based organizations for a comprehensive study of benefits associated with NBIs should be encouraged to reduce health disparities and ensure intergenerational health equity. There is a need for investigation of the mechanisms by which NBIs impact CVD and exploration of the role of CVD biological markers of inflammation among cancer survivors.

Emerging mitochondrial signaling mechanisms in cardio-oncology: beyond oxidative stress

Many anticancer therapies (CTx) have cardiotoxic side effects that limit their therapeutic potential and cause long-term cardiovascular complications in cancer survivors. This has given rise to the field of cardio-oncology, which recognizes the need for basic, translational, and clinical research focused on understanding the complex signaling events that drive CTx-induced cardiovascular toxicity. Several CTx agents cause mitochondrial damage in the form of mitochondrial DNA deletions, mutations, and suppression of respiratory function and ATP production. In this review, we provide a brief overview of the cardiovascular complications of clinically used CTx agents and discuss current knowledge of local and systemic secondary signaling events that arise in response to mitochondrial stress/damage. Mitochondrial oxidative stress has long been recognized as a contributor to CTx-induced cardiotoxicity; thus, we focus on emerging roles for mitochondria in epigenetic regulation, innate immunity, and signaling via noncoding RNAs and mitochondrial hormones. Because data exploring mitochondrial secondary signaling in the context of cardio-oncology are limited, we also draw upon clinical and preclinical studies, which have examined these pathways in other relevant pathologies.