Horticultural Therapy Reduces Biomarkers of Immunosenescence and Inflammaging in Community-Dwelling Older Adults: A Feasibility Pilot Randomized Controlled Trial

A silver bullet for ageing medicine?: clinical relevance of T-cell checkpoint receptors in normal human ageing

Immunosenescence describes dysregulation of the immune system with ageing manifested in both the innate and adaptive immunity, including changes in T-cell checkpoint signaling. Through complex and nuanced process, T-cells lose excitatory signaling pathways and upregulate their inhibitory signaling, leading to ineffective immune responses that contribute to the formation of the ageing phenotype. Here we expand on the expression, function, and clinical potential of targeting the T-cell checkpoint signaling in age and highlight interventions offering the most benefits to older adults' health. Notably, modifications in vaccination such as with mTOR inhibitors show immediate clinical relevance and good tolerability. Other proposed treatments, including therapies with monoclonal antibodies fail to show clinical efficacy or tolerability needed for implementation at present. Although T-cell co-signaling fits a valuable niche for translational scientists to manage immunosenescence, future study would benefit from the inclusion of older adults with multiple long-term conditions and polypharmacy, ensuring better applicability to actual patients seen in clinical settings.

Effects of Health-Promoting Lifestyle on Late-Onset Depression in Older Adults: Mediating Effect of Meaning in Life and Interleukin-6 (IL-6)

Purpose

Late-onset depression (LOD) with poor treatment response has high incidence and mortality in the China's aged people, this study aims to explore the correlation between health-promoting lifestyle, meaning in life, interleukin-6 (IL-6) and LOD for providing scientific basis of LOD prevention and rehabilitation.

Patients and Methods

A total of 496 LOD patients (study group) and healthy older adults (control group) were enrolled and investigated by using the Health-promoting lifestyle Profile-II, revised (HPLP-IIR), Meaning in Life Questionnaire-Chinese Version (MLQ-C), and Hamilton Depression Scale (HAMD). The interleukin-6 (IL-6) in the circulating blood was detected by utilizing ELISA kit.

Results

The results showed that the scores of all factors in HPLP-IIR and MLQ were significantly lower and IL-6 level was higher in the study group than the control group. Scores of most factors in HPLP-IIR and MLQ negatively and IL-6 positively correlated with scores of subscales and total HAMD score. Meaning in life and IL-6 partially mediated the relationship between health-promoting lifestyles and depression severity in the study group, with the mediating effect explains 15.76% and 22.64% of the total effect, respectively.

Conclusion

Health-promoting lifestyles, meaning in life, and IL-6 are predictors of LOD, and an unhealthy lifestyle could induce LOD through the mediating effect of meaning in life and IL-6 in older adults.

Health effects of green prescription: A systematic review of randomized controlled trials

An increasing number of studies have examined the effects of green prescription on various health outcomes. The aim of this study was to systematically review published randomized controlled trial studies on the health benefits of green prescriptions. We searched PubMed, Scopus, and Web of Science for the relevant original articles published in English until June 30, 2023. Our search initially retrieved 26176 articles, of which 31 studies were included in our review after removing the duplicates and excluding ineligible articles based on their titles, abstracts, and full-text review. Consistent positive health benefits of green prescription were reported for psychological health and wellbeing (16 out of 24 studies), cardiometabolic health (five out of nine studies), physical activity (eight out of nine studies), and inflammation (two out of two studies). The reviewed studies did not report any significant benefits in orthopedic conditions, pain, and recovery from exhaustion disorder due to their implemented green prescriptions; however, the number of studies was too small to generalize the effect of green prescriptions on these outcomes. The quality of these studies was generally acceptable, with 28 studies having some concerns regarding their overall risk of bias and only three studies with a high risk of bias. All in all, this systematic review suggests that green prescriptions can be effective in improving various health outcomes, but further studies with larger sample sizes and objective measures are needed.

Effects of horticultural therapy on health in the elderly: A review and meta-analysis

Aim

Given the current aging population, the demand on medical facilities, facilities for elderly care, and even their high prevalence, it is crucial to investigate the advantages of older people. The purpose of our study was to systematically review the existing literature on the health effects of horticultural therapy as a treatment option for the elderly.

Subject and methods

Article searches were conducted through five databases: Web of science, Science Direct, PubMed, EBSCO, and Google Scholar, according to the standard method of systematic evaluation and meta-analysis. Thirty-two published articles were included, and 27 relevant variables were meta-analyzed to assess the benefits of horticultural therapy in terms of physical and psychological functioning in the elderly.

Results

Results show that horticultural therapy may be helpful in helping seniors lose weight -0.195 (95% CI -0.507,0.117), reduce their waist circumference -0.327 (95% CI -0.637, -0.017), lower their stress -0.339 (95% CI -0.610, -0.069) and cortisol -0.902 (95% CI -0.728, -0.002) levels, improve their physical flexibility 0.302 (95% CI 0.036, 0.569), social interaction 0.370, (95% CI 0.115, 0.624), and daily vegetables and fruit consumption 0.688 (95% CI: 0.287, 1.089).

Conclusion

Horticultural therapy may be a useful tool for enhancing the physical, mental and social aspects of the elderly. However, there is substantial heterogeneity and wide variation in the quality of the included studies. Further high-quality studies, rigorous controls and adjustments for significant confounding variables, and larger populations are needed in the future to further our understanding of the link between horticultural therapy and elder health.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-023-01938-w.

Effect of nature prescriptions on cardiometabolic and mental health, and physical activity: a systematic review

Nature prescriptions are gaining popularity as a form of social prescribing in support of sustainable health care. This systematic review and meta-analysis aims to synthesise evidence on the effectiveness of nature prescriptions and determine the factors important for their success. We searched five databases from inception up to July 25, 2021. Randomised and non-randomised controlled studies featuring a nature prescription (ie, a referral or an organised programme, by a health or social professional, to encourage spending time in nature) were included. Two reviewers independently conducted all steps of study selection; one reviewer collected summary data from published reports and conducted the risk of bias assessment. Random-effect DerSimonian-Laird meta-analyses were conducted for five key outcomes. We identified 92 unique studies (122 reports), of which 28 studies contributed data to meta-analyses. Compared with control conditions, nature prescription programmes resulted in a greater reduction in systolic blood pressure (mean difference -4·82 mm Hg [-8·92 to -0·72]) and diastolic blood pressure (mean difference -3·82 mm Hg [-6·47 to -1·16). Nature prescriptions also had a moderate to large effect on depression scores (post-intervention standardised mean difference -0·50 [-0·84 to -0·16]; change from baseline standardised mean difference -0·42 [-0·82 to -0·03]) and anxiety scores (post-intervention standardised mean difference -0·57 [-1·12 to -0·03]; change from baseline standardised mean difference -1·27 [-2·20 to -0·33]). Nature prescriptions resulted in a greater increase in daily step counts than control conditions (mean difference 900 steps [790 to 1010]) but did not improve weekly time of moderate physical activity (mean difference 25·90 min [-10·26 to 62·06]). A subgroup analysis restricted to studies featuring a referring institution showed stronger effects on depression scores, daily step counts, and weekly time of moderate physical activity than the general analysis. Beneficial effects on anxiety and depression scores were mainly provided by interventions involving social professionals whereas beneficial effects on blood pressures and daily step counts were provided mainly by interventions involving health professionals. Most studies have a moderate to high risk of bias. Nature prescription programmes showed evidence of cardiometabolic and mental health benefits and increases in walking. Effective nature prescription programmes can involve a range of natural settings and activities and can be implemented via social and community channels, in addition to health professionals.

Systematic metabolic characterization of mental disorders reveals age‐related metabolic disturbances as potential risk factors for depression in older adults

Mental disorders are associated with dysregulated metabolism, but comprehensive investigations of their metabolic similarities and differences and their clinical relevance are few. Here, based on the plasma metabolome and lipidome of subcohort1, comprising 100 healthy participants, 55 cases with anxiety, 52 persons with depression, and 41 individuals with comorbidity, which are from WCHAT, a perspective cohort study of community‐dwelling older adults aged over 50, multiple metabolites as potential risk factors of mental disorders were identified. Furthermore, participants with mental illnesses were classified into three subtypes (S1, S2, and S3) by unsupervised classification with lipidomic data. Among them, S1 showed higher triacylglycerol and lower sphingomyelin, while S2 displayed opposite features. The metabolic profile of S3 was like that of the normal group. Compared with S3, individuals in S1 and S2 had worse quality of life, and suffered more from sleep and cognitive disorders. Notably, an assessment of 6,467 individuals from the WCHAT showed an age‐related increase in the incidence of depression. Seventeen depression‐related metabolites were significantly correlated with age, which were validated in an independent subcohort2. Collectively, this work highlights the clinical relevance of metabolic perturbation in mental disorders, and age‐related metabolic disturbances may be a bridge‐linking aging and depressive.

A 5-year community program in Singapore to prevent cognitive decline

INTRODUCTION

There is a scarcity of naturalistic follow-up studies on cognitive stimulating activities (CSAs), particularly in a real-world setting and over long-term. We thus investigated a pooled novel CSA intervention to prevent cognitive decline amongst community-dwelling older adults without dementia.

METHODS

Nested within a community-based longitudinal follow-up cohort study of community-dwelling and multi-ethnic older adults (N = 991), a subset of the cohort (n = 264) underwent four single-blinded randomized controlled trials involving four novel CSAs, including mindfulness, horticulture, art therapy, and choral singing. At the cohort's 5-year follow-up, we examined if involvements in the CSAs improved cognition, compared to controls (n = 727). The primary outcomes were changes in global cognition and specific cognitive domain scores measured by the mini-mental state examination (MMSE). Exploratory subgroup analyses stratified by baseline cognitive status and the number of CSAs were also conducted.

RESULTS

Compared to the control group, there was a small improvement in the CSA group on the total MMSE score (d = 0.108) and MMSE-immediate recall score (d = 0.199). Furthermore, subgroup analyses revealed medium effect sizes of improvements (d = 0.420) in cognitive domains in mild cognitive impairment (MCI) (vs. cognitively healthy) and those involved in two CSAs (vs. one CSA).

DISCUSSION

In summary, a CSA intervention improved cognition. MCI and those involved in two CSAs gained greater benefits from the CSAs. These sustained improvements in cognitive functions could have a significant impact on delaying or preventing dementia.

How Nature Benefits Mental Health

Abstract. We present an overview of the evidence of how nature benefits mental health, popular theories used to explain the effects, and the development potential of these theories. A large body of evidence highlights the beneficial effects of nature on mental health, with observed outcomes ranging from alleviating the symptoms of psychiatric disorders to improvements in cognitive abilities. The theoretical backbone for these salutary effects of nature consists of a set of models, mainly the attention restoration theory (ART), the stress reduction theory (SRT), and the Biophilia hypothesis. However, these high-level models are only loosely related and lack a pronounced biopsychological basis. While biopsychological measurements have been used widely in recent years, these efforts have not sufficiently been reflected in theories aiming to explain the benefits of nature contact for mental health. This paper seeks to encourage interdisciplinary work and further theory development to guide both research and practice toward strategically green and healthy living conditions.

Cellular senescence: the good, the bad and the unknown

Cellular senescence is a ubiquitous process with roles in tissue remodelling, including wound repair and embryogenesis. However, prolonged senescence can be maladaptive, leading to cancer development and age-related diseases. Cellular senescence involves cell-cycle arrest and the release of inflammatory cytokines with autocrine, paracrine and endocrine activities. Senescent cells also exhibit morphological alterations, including flattened cell bodies, vacuolization and granularity in the cytoplasm and abnormal organelles. Several biomarkers of cellular senescence have been identified, including SA-βgal, p16 and p21; however, few markers have high sensitivity and specificity. In addition to driving ageing, senescence of immune and parenchymal cells contributes to the development of a variety of diseases and metabolic disorders. In the kidney, senescence might have beneficial roles during development and recovery from injury, but can also contribute to the progression of acute kidney injury and chronic kidney disease. Therapies that target senescence, including senolytic and senomorphic drugs, stem cell therapies and other interventions, have been shown to extend lifespan and reduce tissue injury in various animal models. Early clinical trials confirm that senotherapeutic approaches could be beneficial in human disease. However, larger clinical trials are needed to translate these approaches to patient care.

Effect of horticultural therapy on mental health: A meta-analysis of randomized controlled trials

WHAT IS KNOWN ON THE SUBJECT?: Mental health assessment is a common topic in horticultural therapy (HT). Some study findings were contrary to positive findings, although several studies have explored the effect of HT on mental health and reported positive results. There is weak evidence in the benefits of HT based on evidence-based medicine. Stronger evidence of the link between HT and mental health will help in policy making by health policy makers and governments. WHAT THE PAPER ADDS TO EXISTING KNOWLEDGE?: The purpose of this meta-analysis of randomized controlled trials (RCTs) was to explore the effect of HT on mental health. This study is the first meta-analysis of RCTs to provide critical evidence that HT has a positive effect on mental health. The effect size of HT on mental health was medium (0.55). The included studies had no negative effects on mental health. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: HT should be considered a useful therapy to be integrated in healthcare settings by horticultural therapists to improve mental health. In the HT program, indoor and outdoor plant activities, plant-related arts, crafts and other activities were common interventions to improve specific mental health problems through at least eight sessions. ABSTRACT: Introduction HT has been widely used to promote mental health. However, heterogeneity and sample size issues of randomized controlled trials made it challenging to illustrate effect sizes across the evidence. Aim The purpose of this meta-analysis was to explore the effect of HT on mental health. Methods We used the PRISMA framework. A keyword search of Web of Science, PubMed, ProQuest and Cochrane was performed. The inclusion criteria were HT with RCTs and mental health assessments. A random-effects model was used to perform the meta-analysis. Results A total of 1,056 records were searched, and 18 eligible studies were extracted. The included RCTs had no statistical heterogeneity and publication bias. The meta-analysis showed that the HT experimental groups had a significant and positive impact on mental health compared with the control groups (effect size = 0.55). Discussion HT should be considered for enhancing mental health. The included studies had no negative outcomes and the most common HT intervention was at least eight sessions. Therefore, HT should be considered to enhance mental health. However, the concealed allocation and blinding processes should be improved in future studies. Implications for Practice: This study recommends that HT should be integrated into healthcare settings to improve mental health.

An immunologist's guide to immunosenescence and its treatment

INTRODUCTION

: The ageing process causes several changes in the immune system, although immune ageing is strongly influenced by individual immunological history, as well as genetic and environmental factors leading to inter-individual variability.

AREAS COVERED

: Here, we focused on the biological and clinical meaning of immunosenescence. Data on SARS-CoV-2 and Yellow Fever vaccine have demonstrated the clinical relevance of immunosenescence, while inconsistent results, obtained from longitudinal studies aimed at looking for immune risk phenotypes, have revealed that the immunosenescence process is highly context-dependent. Large projects have allowed the delineation of the drivers of immune system variance, including genetic and environmental factors, sex, smoking, and co-habitation. Therefore, it is difficult to identify the interventions that can be envisaged to maintain or improve immune function in older people. That suggests that drug treatment of immunosenescence should require personalized intervention. Regarding this, we discussed the role of changes in lifestyle as a potential therapeutic approach.

EXPERT OPINION

: Our review points out that age is only part of the problem of immunosenescence. Everyone ages differently because he/she is unique in genetics and experience of life and this applies even more to the immune system (immunobiography). Finally, the present review shows how appreciable results in the modification of immunosenescence biomarkers can be achieved with lifestyle modification.

Horticulture therapy affected the mental status, sleep quality, and salivary markers of mucosal immunity in an elderly population

Horticultural therapy (HT) has been reported to be beneficial to mental and physical health. This study investigated the effects of HT on the psychological status and mucosal immunity of elderly individuals. Twenty-four participants aged 70-93 were recruited from residential facilities and adult day-care services. Six different HT activities were designed and guided by licensed instructors who performed saliva collection and helped the participants complete the questionnaires before and after each activity. The sleep quality scores were collected during the 6 weeks of HT activities. Saliva was collected and analyzed to determine the concentrations of immunoglobulin A (IgA), lactoferrin, chromogranin A (CgA), α-amylase (AA) and total protein (TP). Comparisons of the questionnaire scores between preactivity and postactivity showed that feelings of satisfaction and happiness were significantly enhanced after each activity. In addition, sleep quality was significantly improved after the 6-week course of HT activities. Regarding mucosal immunity, the preactivity IgA and IgA/TP were significantly increased at week 3 and week 6; in addition, the ratio of lactoferrin/TP was significantly decreased at week 6 compared to week 1. The postactivity AA and CgA levels were significantly enhanced at weeks 2, 3 and 5 compared to the corresponding preactivity levels. In conclusions, HT activities significantly improved the happiness, satisfaction, well-being and sleep quality of the elderly. Moreover, mucosal immunity proteins, including IgA, lactoferrin, CgA and AA, were significantly increased.

The Interplay between Housing Environmental Attributes and Design Exposures and Psychoneuroimmunology Profile-An Exploratory Review and Analysis Paper in the Cancer Survivors' Mental Health Morbidity Context

Adult cancer survivors have an increased prevalence of mental health comorbidities and other adverse late-effects interdependent with mental illness outcomes compared with the general population. Coronavirus Disease 2019 (COVID-19) heralds an era of renewed call for actions to identify sustainable modalities to facilitate the constructs of cancer survivorship care and health care delivery through physiological supportive domestic spaces. Building on the concept of therapeutic architecture, psychoneuroimmunology (PNI) indicators-with the central role in low-grade systemic inflammation-are associated with major psychiatric disorders and late effects of post-cancer treatment. Immune disturbances might mediate the effects of environmental determinants on behaviour and mental disorders. Whilst attention is paid to the non-objective measurements for examining the home environmental domains and mental health outcomes, little is gathered about the multidimensional effects on physiological responses. This exploratory review presents a first analysis of how addressing the PNI outcomes serves as a catalyst for therapeutic housing research. We argue the crucial component of housing in supporting the sustainable primary care and public health-based cancer survivorship care model, particularly in the psychopathology context. Ultimately, we illustrate a series of interventions aiming at how housing environmental attributes can trigger PNI profile changes and discuss the potential implications in the non-pharmacological treatment of cancer survivors and patients with mental morbidities.

Increased plasma brain-derived neurotrophic factor (BDNF) as a potential biomarker for and compensatory mechanism in mild cognitive impairment: a case-control study

Background: Previous meta-analyses examining the continuum of Alzheimer’s disease (AD) concluded significantly decreased peripheral brain-derived neurotrophic factor (BDNF) in AD. However, across different meta-analyses, there remain inconsistent findings on peripheral BDNF levels in individuals with mild cognitive impairment (MCI). This issue has been attributed to the highly heterogenous clinical and laboratory factors. Thus, BDNF’s level, discriminative accuracy for identifying all-cause MCI and its subtypes, and its associations with other biomarkers and neurocognitive domains, remain largely unknown.

Methods: To address this heterogeneity, we compared a healthy control cohort (n=56, 45 female) to an MCI cohort (n=40, 28 female), to determine whether plasma BDNF, hs-CRP, and DHEA-S can differentiate healthy from MCI individuals, including two MCI subtypes (amnestic [aMCI] and non-amnestic [non-aMCI]). The associations between BDNF with other biomarkers and neurocognitive tests were examined. Adults with cerebral palsy were included as sensitivity analyses.

Results: Compared to healthy controls, BDNF was significantly higher in all-cause MCI, aMCI, and non-aMCI. Furthermore, BDNF had good (AUC=0.84, 95% CI=0.74 to 0.95, p<0.001) and excellent discriminative accuracies (AUC=0.92, 95% CI=0.84 to 1.00, p<0.001) for all-cause MCI and non-amnestic MCI, respectively. BDNF was significantly and positively associated with plasma hs-CRP (β=0.26, 95% CI=0.02 to 0.50, p=0.038), despite attenuated association upon controlling for BMI (β=0.15, 95% CI=-0.08 to 0.38, p=0.186). Multiple inverse associations between BDNF and detailed neurocognitive tests were also detected.

Conclusions: These findings suggest BDNF is increased as a compensatory mechanism in preclinical dementia, supporting the neurotrophic and partially the inflammatory hypotheses of cognitive impairment.

Mindfulness Awareness Practice (MAP) to Prevent Dementia in Older Adults with Mild Cognitive Impairment: Protocol of a Randomized Controlled Trial and Implementation Outcomes

BACKGROUND

With an aging population, developing non-pharmacological interventions (NPIs) to delay dementia has become critical. Apart from cognitive decline, dementia is associated with multiple pathophysiology, including increased oxidative stress, dysregulated gene expressions, cytokine, neurotrophin, and stress markers, telomere shortening, and deteriorations in brain connectivity. Although mindfulness practices have been proposed to ameliorate these biological changes, no empirical studies were conducted. We thus aimed to investigate the effects of mindfulness awareness practice (MAP) to prevent cognitive decline and improve peripheral biomarkers in community-dwelling older adults diagnosed with mild cognitive impairment (MCI).

METHODS/DESIGN

This was a single-blinded and parallel-group randomized controlled trial with two arms (intervention and active control arms), conducted over nine months. A total of 60 consenting community-dwelling older adults diagnosed with MCI were planned to be randomized in a 1:1 ratio to either the MAP or the Health Education Program (HEP). Interventions were performed weekly for the initial 12 weeks, and monthly for the subsequent six months. Outcome measures were assessed at baseline, 3-month, and 9-month post-intervention by blinded assessors. Primary outcomes were neurocognitive tests, comprehensive peripheral biomarkers, and brain imaging scans. Secondary outcomes included basic health screening measures, affective symptoms, and measures of physical functions. Linear-mixed models were used to examine the effects of MAP on these outcome measures.

SIGNIFICANCE

This is the first randomized controlled trial to systematically investigate the effects of a mindfulness intervention in improving cognitive functions and various biomarkers in community-dwelling older adults diagnosed with MCI. Our findings have the potential to inform mindfulness intervention as a novel approach to delay dementia.

Influence of Exercise on Exhausted and Senescent T Cells: A Systematic Review

The impaired effector function of exhausted and senescent T cells is implicated in cancer progression and inadequate vaccine responses. Exercise has been shown to improve cancer therapy and vaccine efficacy, most likely by improving immune function. However, given inconsistent terminology and definitions, the interactions between exercise and exhausted and senescent T cells remain unclear. We therefore performed a systematic review to investigate the effect of exercise on senescent and exhausted CD8⁺ T cell populations clearly defined by protein surface markers. Thirty articles were included, with the majority (n = 24) reporting senescent T cell populations defined according to a variety of surface markers. Repeated exercise was shown to be beneficial through limiting the accumulation of senescent and exhausted CD8⁺ T cells. This outcome is likely related to exercise-induced preferential mobilization of senescent T cells promoting apoptosis in the peripheral blood compartment. Future studies need to determine the clinical relevance of this effect in cancer prevention and vaccine efficacy. Data regarding exercise and exhausted T cells are limited due to a lack of available high-quality studies. Future studies require the control of confounding variables such as sex and cytomegalovirus (CMV) status, and consistent definitions of exhausted and senescent T cell populations to improve comparisons between studies and interventions.

Synergistic Action of Membrane-Bound and Water-Soluble Antioxidants in Neuroprotection

Prevention of neurodegeneration during aging, and support of optimal brain function throughout the lifespan, requires protection of membrane structure and function. We review the synergistic action of different classes of dietary micronutrients, as well as further synergistic contributions from exercise and stress reduction, in supporting membrane structure and function. We address membrane-associated inflammation involving reactive oxygen species (ROS) that produce immune regulators from polyunsaturated fatty acids (PUFAs) of membrane phospholipids. The potential of dietary micronutrients to maintain membrane fluidity and prevent chronic inflammation is examined with a focus on synergistically acting membrane-soluble components (zeaxanthin, lutein, vitamin E, and omega-3 PUFAs) and water-soluble components (vitamin C and various phenolics). These different classes of micronutrients apparently operate in a series of intertwined oxidation-reduction cycles to protect membrane function and prevent chronic inflammation. At this time, it appears that combinations of a balanced diet with regular moderate exercise and stress-reduction practices are particularly beneficial. Effective whole-food-based diets include the Mediterranean and the MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay diet, where DASH stands for Dietary Approaches to Stop Hypertension).

Association between housing type and accelerated biological aging in different sexes: moderating effects of health behaviors

Introduction: Despite associated with multiple geriatric disorders, whether housing type, an indicator of socioeconomic status (SES) and environmental factors, is associated with accelerated biological aging is unknown. Furthermore, although individuals with low-SES have higher body mass index (BMI) and are more likely to smoke, whether BMI and smoking status moderate the association between SES and biological aging is unclear. We examined these questions in urbanized low-SES older community-dwelling adults.

Methods: First, we analyzed complete blood count data using the cox proportional hazards model and derived measures for biological age (BA) and biological age acceleration (BAA, the higher the more accelerated aging) (N = 376). Subsequently, BAA was regressed on housing type, controlling for covariates, including four other SES indicators. Interaction terms between housing type and BMI/smoking status were separately added to examine their moderating effects. Total sample and sex-stratified analyses were performed.

Results: There were significant differences between men and women in housing type and BAA. Compared to residents in ≥3 room public or private housing, older adults resided in 1–2 room public housing had a higher BAA. Furthermore, BMI attenuated the association between housing type and BAA. In sex-stratified analyses, the main and interaction effects were only significant in women. In men, smoking status instead aggravated the association between housing type and BAA.

Conclusion: Controlling for other SES indicators, housing type is an independent socio-environmental determinant of BA and BAA in a low-SES urbanized population. There were also sex differences in the moderating effects of health behaviors on biological aging.

Social connectedness as a mediator for horticultural therapy's biological effect on community-dwelling older adults: Secondary analyses of a randomized controlled trial

BACKGROUND

Elevated levels of inflammatory marker and a lack of social connectedness are two prominent risk factors for developing dementia and depression. Horticultural therapy (HT) has been shown to improve social connectedness and inflammatory markers. However, the underpinning mechanisms of HT remained unknown. Within this study, we hypothesized that improved social connectedness mediates the effects of HT on IL-6 levels.

METHODS

The present study is a secondary analysis of a randomized controlled trial investigating the bio-psycho-social effects of HT. Social connectedness was operationalized as positive relationships with others (PRWO), a sub-scale of the Ryff's scale of psychological well-being. IL-6 was quantified using a commercial ELISA kit. Outcomes were assessed at baseline, 3-month and 6-month post-intervention. Mediation analyses with bootstrapping were run to investigate our primary hypothesis. All analyses were controlled for covariates.

RESULTS

We recruited 59 participants (78% women; 67.10 ± 4.31 years). 29 participants partook in HT and 30 participants were included in the waitlist control group. At baseline, social connectedness was significantly correlated with IL-6 levels (β = -0.12, 95% CI = -0.21 to -0.03, p = 0.008). Furthermore, social connectedness at 3-month significantly mediated the effects of HT on IL-6 levels at 6-month (β = 0.32, 95% CI = 0.09 to 0.54, p = 0.005; β = -0.25, 95% CI = -0.45 to -0.05, p = 0.016).

CONCLUSIONS

These findings highlight the critical roles of social connectedness as a social determinant of health in eliciting HT's biological effects. When administering HT, interventionalists should consider social connectedness as a modifiable factor for ameliorating increased inflammation in older adults.

Pilot evaluation of horticultural therapy in improving overall wellness in veterans with history of suicidality

OBJECTIVES

Novel approaches to mental health and suicide prevention are lacking. Converging evidence has shown the effectiveness of horticultural therapy (HT) in improving mental health symptoms, but whether it would reduce suicide risk and contributing risk factors is unknown.

DESIGN

Using a cohort model, HT was delivered 3.5 h over four weekly, sessions administered by a registered horticultural therapist to veterans with history of suicide ideation or attempt who felt isolated and experienced ongoing environmental stressors with interest in learning new coping strategies.

SETTING

HT delivery occurred in an urban garden, through a community partnership between the VA (Veterans Administration) and the New York Botanical Garden. Guided by principles of biophilia, participating veterans took part in nature walks, self-reflection and journaling, and planting activities.

OUTCOME MEASURES

Stress, mood, pain, and social isolation levels were measured weekly pre-post HT sessions using thermometer scales, with concordant validity to validated clinical instruments.

RESULTS

Of the 20 men and women with a history of suicide attempts/ideation, HT demonstrated immediate improvements after each session across all symptom domains in magnitude of reduction in stress, pain, mood, and loneliness. The effect sizes were in medium to large range (Cohen's d>.5). Additionally, a single HT session showed a sustained effect over subsequent 2-to-4 weeks as observed by the significantly decreased pre-session thermometer scores in subsequent weeks. Reductions in mood symptoms correlated with decline in suicidal ideation (r_s = 0.63).

CONCLUSION

HT intervention maybe a promising therapeutic modality for improving overall wellness in suicide prevention in at-risk veteran populations.