Co-exploring how environments shape brain health through a planetary health lens: a photovoice study in Auckland, Aotearoa New Zealand

Abstract

Objectives

Dementia prevention and climate action share a common imperative: safeguarding future generations’ health. Despite evidence that nearly half of dementia cases could be prevented by addressing modifiable risk factors, current interventions focused mostly on individual behaviours have yielded mixed cognitive benefits. At the same time, climate change is introducing unprecedented environmental stressors, including air pollution, extreme heat exposure and degraded green spaces, that compound dementia risk. This study aimed to explore how midlife adults perceive the relationship between their daily environments, brain health-related behaviours and planetary health.

Design

Qualitative study using the photovoice method.

Setting

Community setting in Auckland, Aotearoa New Zealand.

Participants

14 community-dwelling adults aged 40–65 years residing in Auckland, Aotearoa New Zealand.

Methods

Participants took photographs and shared narratives to document how their daily environments nurture or threaten lifestyle factors related to brain health. The project involved a five-session participatory process, and data were analysed using reflexive thematic analysis informed by a planetary health framework.

Results

Reflexive thematic analysis, underpinned by a planetary health framework, revealed four inter-related themes: (1) nature as restorative and protective; (2) the mental burden of pollution, sensory overload and climate-driven landscape changes; (3) the protective role of social connection, community care and routines; (4) the co-benefits of education and mindful, eco‐friendly behaviours.

Conclusions

These findings underscore that midlife adults perceive their brain health as intertwined with ecological and social contexts. Dementia risk reduction strategies may therefore benefit from integrating planetary health perspectives that consider environmental conditions alongside social determinants of health. By centring lived experiences and diverse perspectives, photovoice generated context-rich insights that can guide research on more holistic approaches to dementia risk reduction.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• The photovoice approach enabled participants to document lived environmental influences on brain health through photographs and narratives.

• A structured five-session participatory process facilitated iterative reflection and collective interpretation.

• Reflexive thematic analysis provided a systematic framework for analysing qualitative data.

• The small purposive sample limits transferability of findings beyond the study context.

• Recruitment from a single urban setting and a gender imbalance among participants may limit the diversity of perspectives represented.

Introduction

Dementia is a leading cause of disability and dependency in later life, with its global public health effects projected to increase sharply in the coming decades.^{1 2} By 2050, almost 153 million people are expected to be living with dementia worldwide—a nearly threefold increase from 57 million in 2019.³ In Aotearoa New Zealand (AoNZ), this trend is mirrored: over 70 000 people are currently living with dementia, and this number is estimated to exceed 170 000 by midcentury.⁴ The impact of this rise will be felt not only by individuals and their families, but also across the health system, workforce and broader society.⁴ While population ageing is a primary driver of the increase, dementia risk is not distributed evenly: Māori and Pacific peoples of AoNZ experience higher prevalence and earlier onset, driven by structural inequities in access to education, health services and other social determinants of health.⁵

Over the past decade, evidence has emerged linking dementia to a range of modifiable risk factors across the life course, including cardiovascular conditions, mental health, sensory impairment and psychosocial factors.⁶ In AoNZ, almost half of all dementia cases (47.7%) may be preventable if modifiable risk factors were addressed, with even higher proportions for Māori and Pacific peoples.⁷ These estimates underscore the importance of dementia risk reduction and prevention as a public health priority.² In response, multidomain interventions simultaneously targeting individual-level lifestyle and health factors in late midlife and older adults at risk for dementia have been developed and tested, with mixed results to date—while some interventions did not show improvements in cognitive functioning,⁸ some suggested small positive effects.9,11 These mixed outcomes suggest, among other explanations, that targeting individual behaviours and health management alone may be insufficient to achieve larger effects.¹² Increasingly, evidence points to the importance of considering the broader contexts—social, structural and environmental—that shape brain health across the life course.^{13 14}

Environmental factors increasingly recognised as influencing brain health and dementia risk include air pollution,¹⁵ heat exposure,¹⁶ access to green space,¹⁷ food insecurity¹⁸ and neighbourhood deprivation.¹⁹ Rising temperatures and prolonged heatwaves, expected to become more frequent with advancing climate change, are linked to worse cognitive functioning in older adults, particularly in those with higher social disadvantage.²⁰ Adults over 50 years of age are disproportionately affected not only by heatwaves, but also floods and wildfire-related smoke events due to age-related physiological changes, multimorbidity, polypharmacy and reduced mobility.²¹ These escalating environmental stressors coincide with pivotal life transitions in late midlife and early older age, such as work insecurity, caregiving responsibilities, adaptation to retirement and emerging health declines, thereby compounding mental and cognitive health vulnerability.²²

While there is growing recognition that dementia risk is embedded not just in bodies, but in environments people live in,^{14 23} the very environments are increasingly threatened by the cascading effects of environmental degradation and climate change.²⁴ Planetary health provides a compelling framework for understanding these interdependencies.²⁵ It defines human health as inseparable from the health of the natural systems on which we rely.²⁵ This perspective invites a more holistic approach to dementia risk reduction and prevention: one that sees protecting the planet as aligned with protecting the brain—and vice versa.

Given a need for a holistic understanding of these intertwined influences, we turned to photovoice for community-dwelling individuals to document and reflect on how their environments may support or undermine their brain health and opportunities for dementia risk reduction. Photovoice is a participatory, empowering method that fills gaps left by traditional approaches by foregrounding participants’ realities and fostering critical dialogue²⁶—highly suitable to explore lived experience perspectives on the intersection of environmental exposure, lifestyle practices and brain health. As a secondary aim, we tested whether the study changed dementia literacy and evaluated environmental identity (EID) and eco-anxiety. By centring midlife voices, we aimed to generate person-centred insights to inform research examining dementia risk and risk reduction opportunities through a planetary health lens.

Methods

Study design

The study was conducted as a participatory action research project using photovoice to involve community members directly in data collection, analysis and interpretation. By adopting photovoice as our primary method, we positioned participants not merely as subjects but as co-researchers,²⁶ providing them with cameras, if needed, and guiding prompts to document and reflect on the environmental conditions shaping their lifestyle and brain health. This approach, rooted in empowerment education, ensures democratic access to knowledge creation, enabling participants to critically assess their lived realities, generate evidence and advocate for change at both personal and community levels.²⁷ The photovoice methodology was informed by Sutton-Brown²⁸ and is described in detail under Procedure. The study adheres to the Standards for Reporting Qualitative Research guidelines.²⁹

Participants and recruitment

Between late January and mid-March 2024, participants were recruited through a purposive and snowball sampling approach involving printed flyers spread through local community organisations (eg, libraries, community centres), researchers’ networks and geo-fenced, targeted advertisement on social media (Facebook, Instagram) across northern and central Auckland. The target population comprised adults in midlife, considered a critical stage for brain health improvement before dementia risk significantly increases with increasing age.³⁰

Eligibility criteria were: age between 40–65 years, residing in Auckland and willingness and ability to attend study sessions, commit time and engage in photography tasks. Photovoice studies typically involve relatively small groups to facilitate discussion and collective interpretation of images; accordingly, we aimed to recruit between 8–20 participants, which is within the range commonly reported in photovoice research.²⁸

Patient and public involvement

This study was conducted using photovoice, a participatory method that positions community members as co-researchers. As part of the photovoice process, participants co-designed aspects of the study, created and captioned their own images, and collectively interpreted emerging themes during group discussions. This iterative approach ensured that the feasibility and burden of participation were continuously assessed and that activities remained meaningful and acceptable. Regarding dissemination, participants curated their photographs and narratives for two public exhibitions in Auckland. They approved the presentation of their work, received exhibition materials and retained their canvases, ensuring the project’s outcomes were both co-produced and co-owned.

Procedure

The study took place between April and October 2024. Initially, potential participants were invited to contact the study team, who provided an information package about the study aims and procedures. Those who agreed to participate were invited to the first session, where they were officially enrolled in the study based on providing written informed consent to participate, including to produce, discuss and disseminate their photographic narratives. All photographs included in this study were taken by study participants as part of the photovoice process. Participants retain copyright of their images and provided written permission for their use and publication in scientific outputs and public dissemination related to the project. Images containing identifiable individuals were removed to prevent identification. The photovoice data collection process was implemented across five fortnightly 90-minute in-person evening sessions, held at a community centre in Takapuna, North Shore, Auckland (Mary Thomas Centre). The sessions were structured as follows:

Session 1: Setting the frame. The first session focused on relationship-building and establishing a safe, inclusive environment. Participants got to know one another and the facilitation team (project lead, professional photographer and research assistant). We discussed the study design and aims, commitment and consent (including ethical considerations), as well as the session plan. Participants then completed a short, standardised paper-and-pencil questionnaire to collect sociodemographic information, dementia literacy and climate-relevant scales (see Data collection). Followed by a lecture on dementia and dementia risk as well as providing educational materials.

Session 2: Introduction to photography 101 and thematic orientation. After a warm-up community building activity, we discussed the prompts to guide the photography phase. Participants received a respective worksheet. Core prompts comprised: (1) Thinking of your own brain health: What matters to you? What helps you/do you do to keep your brain healthy? What challenges do you face regarding your brain health? How is this related to sustainability, eco-friendliness, environmental protection and/or climate change? (2) Thinking of well-being in your community and/or your neighbourhood: What is important to you about your community? What is it about your community/neighbourhood that supports brain health and well-being? What would you change in your neighbourhood to achieve better brain health outcomes? How is this related to sustainability, eco-friendliness, environmental protection and/or climate change?

The professional photographer then provided a photography 101 training session covering basics of digital photography, ethics and safety considerations. In addition, participants were offered an optional one-on-one photography training session to cater to different photography skill levels and training needs.

Photography sessions: After session 2, participants started taking their photographs. All used their own devices, ranging from smartphones to digital single-lens reflex cameras.

Session 3: Progress check-in and visual storytelling. We began with a community-building exercise. Next, we held a progress check‐in, inviting participants to discuss how their photography assignments were unfolding, troubleshoot any issues and address questions about framing, focus or ethical considerations. The professional photographer then transitioned to visual storytelling training, presenting key principles such as composition, perspective and context that help a single image convey layered meaning. Finally, we introduced the SHOWED technique for crafting captions,²⁶ using prompts: What do you See? What is Happening? How does this relate to Our lives? Why does this situation exist? How could this image Educate others? What can we Do about it? At the end of the session, we assigned participants to continue taking photographs and, prior to session 4, submit up to six of their preferred images and upload them via a unique, secure link to a dedicated Massey University OneDrive folder. This OneDrive instance complies with the University’s data security guidelines, employing encryption in transit, access controls tied to institutional credentials and storage within Massey’s managed cloud environment. Only the research team could access the files.

Session 4: Photography selection and caption crafting. Participants reconvened to finalise their contributions and lay the groundwork for public sharing. First, we displayed prints of all submitted photographs across the room for collective viewing. Then, each participant selected their two preferred photographs, guided by the emerging group themes and their personal narratives. Using the SHOWED framework introduced previously, participants then crafted and refined captions, ensuring each image was paired with a concise narrative that linked individual experience to broader planetary and brain health themes.

Session 5: Collective meaning making and exhibition planning. We dove into collective meaning making, as participants reviewed selected photographs. We discussed overlaps and divergences in interpretation and gave room for reflections on the process and photographs. We then moved into exhibition planning. To capture the impact of the photovoice process, participants completed a postproject questionnaire reassessing dementia literature, EID and eco-anxiety.

At all sessions, catering was provided, and participants received a general-purpose voucher valued at NZD40 as a means of incentive.

Data collection and analysis

Data sources included the pre-questionnaire and post-questionnaire, photographs and captions, as well as researcher field notes. The questionnaire collected standardised sociodemographic information (pre only), knowledge about dementia and dementia risk factors adapted from Heger et al³¹(see online supplemental file 1), and climate-relevant information (revised EID scale,³² Hogg Eco-Anxiety Scale/HEAS-13).³³ EID measures the extent to which individuals incorporate the natural environment into their self-concept. 14 items are rated on a 1–7 Likert scale, with higher scores indicating stronger EID. HEAS-13 captures cognitive-emotional, behavioural and affective responses to climate change. 13 items are rated on a 1–5 Likert scale, with higher scores reflecting greater eco-anxiety.

Baseline sociodemographic characteristics were summarised using frequencies and percentages for categorical variables and mean (SD) for continuous variables. The main analysis drew on participants’ photographs and captions and was conducted using reflexive thematic analysis,³⁴ focusing on patterned meanings across the photo-caption set. Both photographs and captions were treated as units of meaning. For each image, we created an image log comprising metadata, a denotative (objective) visual description and basic compositional notes. To streamline preparation, the denotative description was auto-generated with a locally run image-captioning model and then human-verified by the researchers; the participant-authored caption remained the primary interpretive source. Materials were imported to NVivo, where we applied an inductive–deductive coding approach. Codes generated by the researchers were compared and refined collaboratively, ensuring consistency and transparency in interpretation. Themes were developed by synthesising participant-generated meanings with the research team’s coding, maintaining close alignment with participants’ language and perspectives.

We additionally analysed pre-intervention and post-intervention survey data. Dementia risk factor knowledge (20 items) and dementia knowledge (7 items) were rated on Likert scales (eg, 1=strongly agree to 5=strongly disagree), with scoring aligned to the correct scientific response (lower scores=greater knowledge). For each item, the distribution of responses was calculated as percentages and visualised using 100% stacked bar charts with pre–post values next to each other. Mean agreement scores were computed for each knowledge domain, reverse-coding items where necessary and compared between time points using paired t-tests or Wilcoxon signed-rank tests, as appropriate. Self-rated overall dementia knowledge (single item), EID and eco-anxiety (HEAS-13) were analysed as continuous variables, with pre–post comparisons using the same paired-sample approach. All statistical analyses were conducted in Python, with a focus on effect sizes (Cohen’s d) due to the small sample size.

Researcher characteristics and reflexivity

The study was led by researchers with expertise in dementia epidemiology, ageing and social determinants of health (SR), and psychology and ageing (FA), supported by a professional photographer and a research assistant. The research team brought a strong commitment to participatory and equity-focused approaches, which shaped the choice of photovoice as the primary method. SR’s prior work with community and Indigenous groups, and the team’s interest in planetary health, informed the assumption that brain health is best understood in its social and environmental contexts. These professional backgrounds and values have influenced both the framing of research prompts and the interpretation of participants’ narratives. To mitigate the influence, reflexive practices were used, including collaborative theme development, open dialogue during group sessions and transparency about researcher positionality. The team’s interdisciplinary composition, combining public health, psychology and arts practice, supported critical reflection and helped balance potential biases.

Results

Participant characteristics

16 participants enrolled in the study, but 2 dropped out at the first session (the study did not meet their expectations) and 14 (87.5%) participated throughout. Participants were on average 49.2 (SD=7.0, range=40–63) years old and the majority was female (85.7%). All participants had a high level of education. There was high ethnic/cultural diversity among the sample, and every participant was born in a different country. Full details are presented in table 1. Of the 14 completers, 12 (85.7%) provided postquestionnaire data.

Table 1. Characteristics of study participants (n=14).

Variable	Category/metric	n or mean±SD	%
Age	Years	49.2±7.0
Gender	Female	12	85.7
	Male	2	14.3
Education	Postsecondary cert, diploma or trade diploma	7	50.0
	University degree	7	50.0
Work status	Full-time paid work, for an employer	8	57.1
	Part-time paid work, for an employer	1	7.1
	Part-time self-employed paid employment	1	7.1
	Fully retired, no paid work	1	7.1
	Full-time homemaker	1	7.1
	Unable to work due to health or disability issue	1	7.1
	Unemployed and seeking work	1	7.1
Marital status	I am married	8	57.1
	I am single	3	21.4
	I am a widow or widower	1	7.1
	I am in a civil union/de facto/partnered relationship	1	7.1
	I am divorced or permanently separated from my legal husband or wife	1	7.1
Household composition (living with…)	My spouse or partner(s)	8	57.1
	My parent(s) and/or parent(s)-in-law	2	14.3
	My son(s) and/or daughter(s)	2	14.3
	I live alone	1	7.1
	Other people not listed above	1	7.1
Ethnic/cultural identity	European	3	28.5
	New Zealand European	1	7.1
	Samoan	1	7.1
	Indian	1	7.1
	Welsh	1	7.1
	South African	1	7.1
	Australian	1	7.1
	Sri Lankan	1	7.1
	Korean	1	7.1
	Pakistani	1	7.1
	Taiwanese	1	7.1
Country of birth	UK	2	14.3
	New Zealand	1	7.1
	Australia	1	7.1
	India	1	7.1
	South Africa	1	7.1
	Sri Lanka	1	7.1
	South Korea	1	7.1
	Slovakia	1	7.1
	Pakistan	1	7.1
	Hong Kong	1	7.1
	Germany	1	7.1
	Taiwan	1	7.1
	Macedonia	1	7.1
Self-rated overall dementia knowledge	Likert scale agreement	2.08±0.51
Dementia knowledge	Likert scale agreement	2.29±0.39
Dementia risk factor knowledge	Likert scale agreement	2.41±0.42
Environmental identity	Likert scale agreement	6.27±1.04
Eco-anxiety	Likert scale agreement	1.97±0.64

Empty categories are not listed.

Themes identified from photographs and captions

Across the 28 photographs and captions (two entries per participant), we identified four main themes. Photographs and captions can be found in the supplement which is suggested to be viewed concurrently with the theme descriptions. Images (n=8) containing potentially identifiable individuals were not included.

1. Nature as restorative and protective: Participants consistently described nature as a powerful source of restoration and protection for mental well-being. Contact with green and blue spaces, whether vast landscapes or fleeting urban encounters, was linked to stress relief, cognitive renewal and a sense of belonging. Immersion in expansive natural settings was described as sanctuary-like. In ‘A Place for Lunch’, one participant recounted the simple act of eating beneath trees on Fort Street as ‘better than sitting in the office’, offering a reprieve from the pressures of work. Similarly, ‘Day Out at Piha Beach’ illustrated the free, accessible therapeutic value of coastal reserves, where ‘physical activity has substantial benefits to our brain… neurogenesis helps maintain brain health’. Smaller-scale encounters provided what participants described as ‘micro-moments’ of connection with nature in otherwise urbanised lives. The lone ‘Dandelion’ was celebrated for its ‘raw beauty’ and role in sustaining pollinators, an understated reminder of the ecological systems that support food security and cognitive nutrition. In ‘Kitty Cat’, the simple joy of a neighbour’s visiting pet was framed as ‘the best serotonin-boosting head bops… a welcome visitor’ that punctuated daily routines with warmth. Participants also reflected on built-nature hybrids as symbols of endurance and the integration of nature into urban life. ‘The Lamp’, a streetlamp overgrown by bush yet still standing, was seen as a metaphor for resilience ‘when nurtured’. In ‘Evening Stroll’, a boardwalk weaving through mangroves was praised as an example of urban planning that makes ‘touch with nature easier for all’, supporting physical, mental and social health.

2. Environmental threats and cognitive stressors: Alongside restorative experiences, participants expressed concern about environmental degradation and urban stressors, which were seen as eroding both ecological and cognitive health. Pollution and debris were described as both physical scars on landscapes and emotional burdens. In ‘Rangitoto Clean Up’, floating plastic fragments were a tangible reminder that ‘everything we drop… affects ocean animals and ends up’ in cherished places. ‘Broken’ used the image of a discarded chair among wood offcuts to comment on the hidden mental costs of a throw-away culture, where ‘once precious items… now [lie] in debris’. Sensory overload in urban areas, particularly from light and noise, was also seen as a cognitive disruptor. ‘The Dark Places’ lamented that excessive artificial lighting denies 99% of people the ability to view the night sky, eroding sleep quality and threatening insect populations essential to food webs. As one participant noted, ‘darkness also holds peace’. For some, the most unsettling stressors were climate-driven changes. ‘Mt. Cook – Ever Changing Landscape’ depicted retreating glaciers as a visible sign of irreversible transformation, prompting calls to ‘work harder to protect… so future generations can enjoy it’. In ‘Rusted’, rusting metal debris washed ashore symbolised slow but persistent environmental decline; ‘man-made remnants… take years’ to degrade, all the while contributing to ocean pollution.

3. Social and community-centred well-being: Participants also emphasised that cognitive resilience is shaped not only by the natural environment but by the quality of social relationships, shared activities and meaningful roles, which were seen as sources of resilience against climate change. Acts of collective caring and resource-sharing were valued for their capacity to stimulate minds and strengthen bonds. ‘Book Box’ described a community book exchange that ‘encourages everyone to read’, fostering curiosity and shared learning while fostering sustainability. In ‘Zooming Home’, the choice to use public transport reduced carbon emissions and commuter stress, allowing participants to ‘get to where I want without driving in rush hour’. Celebrations of kinship underscored the mental health benefits of intentional social connection. ‘Tofā Feavata’i’ captured a garage lunch for visiting whānau, highlighting ‘deliberate connections with respect’ as a source of belonging. ‘Smiles, Sunshine and Sweetness’ depicted a mother-daughter day in nature, reflecting the belief that positive emotions ‘attract positivity’ for brain health. Stability, routine and purpose were seen as cognitive anchors in a changing world. In ‘Somewhere You Belong To’, a local business was described as ‘part of our history’ and a source of security through ‘having a stable job’. ‘On The Bus’ reframed a son’s daily 90-minute commute as a purposeful pause for reflection and a contribution to climate action, ‘actively reducing his carbon footprint’.

4. Education, mindfulness and cobenefits: Finally, participants described how conscious awareness and intentional behaviour could produce benefits for both brain health and the planet. Mindful attention to light, dark and presence was reflected in ‘When You Are in Darkness’, where noticing ‘even a small bit of light’ was both a metaphor for seeking help and a call for sustainable practices such as LED lighting, solar panels and community counselling services. In ‘Enlightenment’ and ‘Awakening and Blissfulness’, Buddha imagery and contrasts of light and shadow were used to illustrate mindfulness in nature as a way of calming thought processes. Behavioural choices with dual benefits illustrated the synergy between personal health and environmental sustainability. ‘Zooming Home’ framed bus commuting as both low-carbon and stress-reducing, while ‘Breakfast’ depicted a nutrient-rich, mindful morning of muesli, fruit and reading as a ‘brain-planet co-benefit’. Themes of growth, resilience and future orientation linked the personal to the intergenerational. ‘Growth and Resilience’ likened a flower’s pollination cycle to the ripple effects of ‘one person’s positive, driven attitude’ influencing others. In ‘Twin Girls Exploring Their World’, concern about clutter and screen use inspired a call to ‘just play… and enjoy’, fostering clarity and creativity for future generations.

Overall, the four themes illustrate how brain health and resilience can be shaped by the interplay of restorative connections with nature, awareness of environmental threats, strong social bonds and community engagement, and mindful, future-oriented actions that generate cobenefits for both brain health and the planet.

Dementia literacy

Self-rated dementia knowledge showed that, on average, most participants stated to know ‘something’ about dementia. Comparing the data across 12 pre-questionnaires and post-questionnaires, the pre-mean score was M=2.08 (SD=0.53) and the postscore M=1.92 (SD=0.29), suggesting a change of −0.17 and higher self-rated dementia knowledge (Wilcoxon rank test: p=0.317, d=0.29), indicating a non-significant change and small effect (figure 1). Objective dementia knowledge across seven items suggested a change of −0.37 from pre (M=2.29, SD=0.45) to post (M=1.91, SD=0.44), suggesting significant knowledge gain and a large effect (paired t-test(1) = 3.64, p=0.0039, d=0.72) (figures2 3). Dementia risk factor knowledge showed a change of −0.28 from pre (M=2.42, SD=0.45) to post (M=2.14, SD=0.56), suggesting a non-significant knowledge gain and small-moderate effect (paired t-test(11) = 1.21, p<0.252, d=0.35) (figure 4 and online supplemental figure S1).

Figure 1. Average agreement rating for overall self-rated dementia knowledge, with lower scores indicating higher knowledge (aka better agreement). (How much do you know about dementia? 1—A lot, 2—Something, 3—Rather little, 4—Nothing).

Figure 2. Agreement with dementia knowledge items at the beginning of the study (pre) and at the end of the study (post).

Figure 3. Average agreement across seven dementia knowledge items at the beginning of the study (pre) and at the end of the study (post). Lower scores indicating higher knowledge (aka better agreement).

Figure 4. Average agreement across 20 dementia risk factor items at the beginning of the study (pre) and at the end of the study (post). Lower scores indicating higher knowledge (aka better agreement).

Environmental identity and eco-anxiety

The 14 participants showed on average a high level of EID (M=6.27, SD=1.04) and low-to-moderate eco-anxiety (M=1.97, SD=0.64). Considering a pre–post comparison of the 12 available datasets, EID changed −0.31 from pre (M=6.03, SD=0.88) to post (M=5.72, SD=0.86; paired t-test(11) = 1.22, p=0.248, d=0.35), suggesting a non-significant difference and small-to-moderate effect towards lower EID. Eco-anxiety among the 12 pre–post survey completers showed no change (−0.02) from pre (M=1.99, SD=0.68) to post (M=1.97, SD=0.64; paired t-test(11) = 0.19, p=0.854, d=0.05).

Knowledge translation and public exhibition

Two curated public exhibitions were held in September and October 2024 at a local gallery in Auckland. They featured the participants’ selected photographs and narratives, with consented names included. The exhibition was designed to serve as both an awareness-raising tool and a form of public dissemination. A printed and digital exhibition brochure was developed to extend the project’s reach. Key stakeholders, including health practitioners, policymakers, researchers and community members, were provided with the materials. The exhibition served as both a celebration of lived experience and an action-oriented forum to spark conversation about how dementia risk reduction can be supported through more equitable and sustainable environments. Participants were given copies of the brochures, and they received their canvases after the exhibition.

Discussion

This study aimed to co-explore lived-experience perspectives on opportunities for dementia risk reduction from a planetary health lens by engaging adults in midlife through participatory action research applying photovoice. Using a reflexive thematic analysis, we identified four overarching themes across the 28 resulting photographs and captions: (1) nature as restorative and protective; (2) the mental burden of pollution, sensory overload and climate-driven landscape changes; (3) the protective role of social connection, community care, education and routines; (4) the cobenefits of education and mindful, eco‐friendly behaviours, illuminating how everyday environments and practices may shape brain health and dementia risk. Participants portrayed green and blue spaces such as parks, beaches and street vegetation as key sites for stress reduction, cognitive restoration and sources of resilience. Conversely, waste pollution, light pollution and climate-driven landscape changes were depicted as cognitive and mental stressors. Social connections and communal care emerged as vital for mental stimulation and emotional support, buffering isolation and sources of mutual support and collective meaning making amid climate change threats. Lastly, mindful practices and eco-friendly behaviours (eg, choosing public transport, energy-efficient lighting) demonstrated how personal agency can simultaneously benefit brain and planetary health.

The theme of the protective role of nature aligns with evidence that access to urban green spaces supports cognitive function and reduces dementia risk.^{17 35} For example, Paul et al³⁵ showed that increased exposure to urban green space was associated with reduced dementia incidence among 1.7 million adults from Ontario, Canada. A study among Australians aged 45 and older, residing in Sydney, Newcastle and Wollongong, suggested that higher urban tree canopy cover, but not more open grass, was associated with lower dementia risk.¹⁷ Spending time in nature has been found to improve cognitive abilities, including attention, memory and executive functioning.³⁶ Fine particulate air pollution, an established risk factor for dementia via systemic inflammation and cerebrovascular damage,³⁷ was vividly illustrated by participants’ depictions of waste and proximity to traffic. The sensory overload from light pollution, yet underexplored in dementia research, echoes findings on disrupted sleep,³⁸ which in turn can detrimentally impact cognitive functioning.³⁹

The social and community theme reinforces the importance of social engagement in dementia risk reduction. Social isolation accounts for a significant proportion of dementia risk and is addressed in WHO guidelines on risk reduction of cognitive decline and dementia.¹ Photovoice participants emphasised reciprocal care and communal sharing—practices that foster social reserve.⁴⁰ Notably, community and collective meaning-making have been suggested as key aspects in mitigating climate anxiety and concerns about climate change.⁴¹

Finally, the theme of mindfulness and cobenefit behaviours echoes the planetary health concept: actions beneficial to both the environment and human health.²⁵ In the photovoice narratives, participants described everyday practices that simultaneously supported personal well-being and environmental sustainability, including mindful engagement with self, nature, mobility and food choices. Our findings suggest that embedding sustainability into daily lifestyle routines, such as using public transport or making mindful dietary choices such as favouring a plant-based diet, may amplify the protective effects on brain health. Indeed, a large longitudinal analysis of data of over 180 000 participants from the UK Biobank cohort study showed that a plant-based diet rich in healthful plant foods was associated with lower risk for dementia and depression.⁴² Plant-based diets are also widely recognised within the planetary health framework as dietary patterns that can generate cobenefits by simultaneously reducing environmental impacts of food systems while supporting human health. Similarly, mindfulness practices have been associated with attenuated cognitive decline and lower amyloid-β and τ accumulation in older adults at risk for Alzheimer’s disease, suggesting a neuroprotective role that may reduce dementia risk.⁴³ Such practices may support brain health by lowering stress, improving attention control and supporting adaptive coping, thereby protecting brain health in later life and, when practised in nature, may enhance environmental awareness, stewardship and resilience to climate-related stressors.⁴⁴

Overall, this illustrates that brain health and planetary health are deeply intertwined, consistent with the planetary health framework which emphasises the interdependence between human health and the natural systems on which it depends.²⁵ Within this perspective, safeguarding natural systems can be understood as a prerequisite for environments that enable human flourishing across the life course, including healthy ageing and brain health. Community-dwelling adults readily grasp this complexity when engaged through participatory approaches. The photovoice process foregrounded multiple, tangible pathways for integrating dementia risk-reducing behaviours with environmentally sustainable practices, ranging from restorative engagement with nature and reduction of environmental stressors to fostering social connection and adopting mindful, eco‐friendly routines. These themes reflect key dimensions of planetary health, highlighting how environmental conditions, social contexts and everyday behaviours interact to shape opportunities for brain health. In doing so, the study not only highlighted possible co-benefits for cognitive and planetary resilience, but the study also enhanced dementia literacy, empowering participants to recognise how everyday choices and environments can support both brain and environmental well-being.

Strengths and limitations

A major strength is the participatory photovoice methodology itself, which empowered participants as co-researchers and yielded rich, contextually grounded insights. Our reflexive thematic analysis allowed for an inductive–deductive interrogation of narratives. Inclusion of diverse cultural perspectives added to the study’s relevance for holistic dementia risk reduction.

This study has several limitations. The rather small sample size, drawn from a single urban region, limits generalisability. Participants were self‐selected, had high education levels and showed high EID, which does not reflect the broader population, introducing selection bias. Moreover, the sample was predominantly female, which may have influenced the perspectives captured, as gender differences may exist in environmental engagement, caregiving roles and health-related behaviours related to brain health. While photovoice illuminates lived experience, it is inherently subjective: the meaning of images and captions may vary between participants and researchers, and group discussions may have shaped the issues highlighted, leading to some convergence of perspectives. Social desirability bias may also have influenced the photographs and narratives, with participants potentially favouring pro-environmental or pro-health representations. The method is more suited to capturing visible, tangible phenomena; less observable or structural determinants of brain and planetary health may therefore be underrepresented. Additionally, differences in photography skills and comfort with technology may have influenced the type and quality of submissions. Photovoice provides a temporal snapshot; seasonal or evolving environmental conditions and changes in personal circumstances cannot be captured. Finally, we did not collect objective indicators of environmental vulnerability (eg, pollution exposure, or neighbourhood characteristics).

Conclusions

Our findings underscore that dementia risk is not merely perceived as an individual biopsychosocial and medical issue but as deeply rooted in environmental contexts. Participants cared and were aware of the ways in which their surroundings, communities and daily choices intersect with brain health—similar educational public health campaigns may be able to reach broader groups. Strategies that protect and restore natural environments, mitigate pollution, foster social cohesion and promote mindful, sustainable behaviours hold promise for synergistic benefits to brain and planetary health—a necessity amid the concurrent megatrends of population ageing and climate change. Integrating these insights into public health policy and urban planning, for example, expanding green infrastructure, regulating light pollution and enhancing community transport, could inform a more holistic approach to dementia risk reduction. Future research could evaluate the impact of integrated interventions on cognitive outcomes across diverse populations.

Data availability statement

Data are available upon reasonable request.