Traditional knowledge, planetary health and healthcare: a systematic review

Healthcare plays a crucial role in managing disease and injury, yet tensions exist within its broad scope, from public health to highly technical medical interventions. Resource allocation between public health initiatives and hospital care is one example of a tension, while a larger-scale tension exists between planetary health and healthcare’s environmental impact. Healthcare, which accounts for 4.4% of global greenhouse gas emissions,¹ contributes significantly to climate change. Healthcare generates large volumes of waste, often disposed of through environmentally harmful methods like incineration.² Some healthcare supply chains involve unethical labour practices,³ making them a double-edged sword, benefitting some people at the expense of others, usually in different localities.

The recognition that human health and the health of Earth are inextricably linked^4,5 has led clinicians to create a movement for planetary health.⁶ Although the literature on planetary health has been substantial in recent time, much of it appears to come from a “modern” paradigm⁷ in which the issue of climate change is viewed as a problem to be solved external to ourselves. By contrast, traditional viewpoints often regard the world and all living beings as interconnected,⁸ as expressed by Al-Delaimy et al.: “Earlier civilisations … consider the earth, nature, and its bounties a privilege to be cherished and respected because of the interdependence with the environment for their survival … They have ensured that they are part of the eco-system and are a positive force to live and let animals, plants and all other creations live.”⁹

Interconnectedness is also explained in a statement made at the 23rd World Conference on Health Promotion in 2019: “Core features of Indigenous worldviews are the interactive relationship between spiritual and material realms, intergenerational and collective orientations, that Mother Earth is a living being – a ‘person’ with whom we have special relationships that are a foundation for identity, and the interconnectedness and interdependence between all that exists, which locates humanity as part of Mother Earth’s ecosystems alongside our relations in the natural world.”¹⁰

The burden of climate change does not fall equally on all. Indigenous populations are one of the vulnerable groups that are disproportionately burdened by biodiversity loss, climate change and rising sea levels.¹¹ The reasons are multifactorial. Indigenous peoples often have a close relationship with and dependence on the land, sea and other natural resources. Additionally, Indigenous populations often carry the burden of social and economic inequity.¹² Added to this is the growing body of evidence that Indigenous management and land tenure provide valuable lessons in how to safeguard natural resources.¹³

Therefore, the purpose of this review is to scope the international literature on scientific research at the nexus of the natural environment, traditional knowledge and healthcare and to identify opportunities for future research and policy.

Methods

The protocol for this review was registered at the Open Science Framework (OSF), reference osf.io/r4yh2. Study data are openly available on OSF (see: https://osf.io/r4yh2/). This report conforms to the Preferred Reporting Items for Systematic reviews and Meta-Analyses – Scoping Reviews¹⁴ and the Enhancing Transparency in Reporting the Synthesis of Qualitative Research,¹⁵ as shown in Tables S1 and S2 at OSF (see: https://osf.io/r4yh2/).

The eligibility criteria included research papers that addressed environmental sustainability, Indigenous or traditional knowledge or ways of knowing and human healthcare. Excluded were reviews, editorials and opinion pieces. No date or language limits were applied. Information sources for database searches were the Web of Science, Scopus, Medline and Embase. Two researchers (JA and JH) developed the search strategy with advice from librarians at The University of Auckland’s Philson Library. Searches reflected the three main concepts: the natural environment, traditional knowledge and healthcare. Combinations of key words and Medline subject headings were trialled in an iterative process to arrive at the final search strategy. The search strategy for Web of Science was as follows: TS = (Indigenous or “first nation people” or “native people” or tribe or “Indigenous population” or “Indigenous health services” or “Indigenous Canadians” or “Pacific Islander” or “Native Hawaiian” or “American Indian” or “Australian Aboriginal” or “Torres Strait Islanders” or “oceanic ancestry group” or Māori) AND TS = (healthcare or health-care or “health care” or “health service” or “health system” or “community-based care” or “primary care”) AND TS = (“planetary health” or “environmental sustainab” or “environmental health” or “environmental restoration” or “environmental remediation” or “natural resources conservation” or “conservation of natural resources” or deforestation or “environmental protection” or “environmental policy”). The search strategy for Medline is available in Table S3 at OSF (see: https://osf.io/r4yh2/files/osfstorage). Searches were performed from June to August 2023 and updated in April 2024.

Two reviewers (JA and JH) performed the searches, imported the results into the online platform Rayyan,¹⁶ removed duplicates, screened titles and abstracts and screened full text articles for eligibility. Screening was performed independently and blinded. Blinding was then removed and the two reviewers resolved any discrepancies around eligibility by discussion and consensus. In addition to database searches, the two reviewers citation tracked and searched the internet for relevant papers.

Two reviewers extracted data from each paper onto a spreadsheet. This recorded the article’s characteristics (author, country of origin and year of publication), the aims/purpose of the study (which was obtained either from the abstract or the introduction of the paper), the study population and sample size if available, the methodology if relevant, the study outcomes and details, and key findings related to the scoping question. The quality of included papers was assessed using a checklist based on the Standards for Reporting Qualitative Research¹⁴ that scored each paper’s compliance with each of the 20 items.

For thematic synthesis, we adapted Braun and Clarke’s method of reflective thematic analysis^17,18 and Noblit and Hare’s method of meta-ethnography¹⁹ into the following steps:

1. Identify the area of study and the theoretical paradigm.
2. Literature search and paper selection.
3. Quality assessment of each included paper.
4. Familiarisation with the dataset/papers.
5. Code key metaphors, ideas, phrases and concepts.
6. Generate initial themes.
7. Refine, define and, as necessary, rename themes to minimise overlap and ensure overall coherence.
8. Express the results in a written report and other forms of communication.

A detailed description of thematic synthesis is available in the study protocol at OSF (see: https://osf.io/r4yh2/).

Results

After removing duplicates, we identified a total of 374 references, which, after screening, were narrowed down to 22 reports^20–41 from 21 studies, as shown in Figure 1. Publication dates ranged from 2006 to 2024 with 15 studies within the last 10 years, as shown in Table 1. Geographically, research originated from Africa, Australia, India, Indonesia, and Central and North America as shown in Table S4 at OSF (see: https://osf.io/r4yh2/files/osfstorage). Quality scores are shown in Table S5 at OSF (see: https://osf.io/r4yh2/files/osfstorage). Quality assessment yielded a mean score of 12/20 (range 6–18, SD 3.5).

From the coded studies, six initial themes emerged: holistic wellbeing, multiple ways of knowing, Earth, community, justice and healthcare system diversity, as shown in Table S6 and Figure S1 at OSF (see: https://osf.io/r4yh2/). These were further refined into two overarching themes: “holistic wellbeing” and “epistemological pluralism” as shown in Figure S2 at OSF (see: https://osf.io/r4yh2/files/osfstorage). The holistic wellbeing theme encompasses the relationship between nature and health, emphasising the need for healthcare to adopt a nature-centred, culturally informed understanding of health. The epistemological pluralism theme highlights the value of integrating diverse knowledge systems in healthcare to enhance health outcomes.

Theme 1: holistic wellbeing

The core idea of the holistic wellbeing theme is that healthcare needs a more holistic concept of wellbeing as a basis of healthcare planning than it currently has. Nineteen papers had codes pertaining to holistic wellbeing, as shown in Table S6 at OSF (see: https://osf.io/r4yh2/files/osfstorage). Beaudin²⁴ explored the health concepts of the Oneida Nation in Canada as they relate to a World Health Organization (WHO) framework called the International Classification of Functioning, Disability and Health (ICF). Although the ICF framework promotes a holistic approach, it lacks a cultural dimension, which is essential for mutual understanding. Beaudin proposed a three-step process for cultural system improvement: 1) learning through engagement, 2) interpretation and reform, and 3) application and engagement.²⁴

The Mandala of Health, a model proposed by Hancock,⁴² was adapted by Langmaid et al.³² to incorporate traditional knowledge systems in Australia. The authors found that “The cultural context of communities and … understanding of Indigenous cultures are crucial elements of health promotion.”³² Building upon this framework, Langmaid et al. ³² developed a modified Mandala of Health that emphasised the interconnected aspects of ecosystems with the human mind, body and spirit.

Redvers et al.³⁷ used a consensus approach led by Indigenous people from around the world to develop a model of planetary health that interconnected the following components: Mother Earth–level determinants (respect of the feminine and ancestral legal personhood designation); interconnecting determinants (human interconnectedness within nature, self and community relationships, the modern scientific paradigm, and governance and law); and Indigenous peoples–level determinants (Indigenous land tenure rights, Indigenous languages, Indigenous peoples’ health, and Indigenous elders and children).³⁴

Models that support planetary health consider nature to be an integral foundational aspect rather than a single “leg” so to speak. DiPrete Brown et al. reflected this in their “three-legged stool” model.³⁰ In their initial model they equated three aspects of sustainability—environmental protection, economic development and social development—with a three-legged stool. However, the environment is not merely a component but the foundation of life on Earth; therefore, the authors modified the model to make the environment the “floor” on which the stool stands and the three legs of the stool became 1) human rights and related legal frameworks, 2) gender analysis and gender mainstreaming practices, and 3) local and Indigenous history, knowledge and ways of knowing.

The importance of place-based local environments, variously referred to as Earth, land or country, was prominent in the literature.^{20,25–27,38} Brand et al. explained that “The Aboriginal flag, like the roots keeps me grounded, turn to my boodja [land or country], to keep connected you know, that my spirit my Wirrin [spirit] is keeping me strong.”³⁸ A participant in the study by Kingsley et al. explained that “If the land’s healthy, the animals are healthy, it makes the people healthy … but if the animals don’t have habitat than that means the land and people are sick.”²⁶ Other determinants of health referred to in the studies included: land and country; sense of Mother Earth; intergenerational health; reciprocity—caring, respect and gratitude; social, cultural and economic determinants of health; and justice, self-determination, community empowerment.

Theme 2: epistemological pluralism

The second major theme is epistemological pluralism, which advocates for the integration of multiple knowledge systems in healthcare. Redvers et al.³⁴ discussed epistemological pluralism using the metaphor of a “two-eyed seeing lens” as originally described by Bartlett et al.: “Two-eyed seeing is the gift of multiple perspectives treasured by many aboriginal peoples and explains that it refers to learning to see from one eye with the strengths of Indigenous knowledges and ways of knowing, and from the other eye with the strengths of Western knowledges and ways of knowing, and to using both these eyes together, for the benefit of all.”⁴³

2.1: systems thinking

Traditional knowledge connects nature with society in a way comparable to complex systems thinking. In an ethnographic study on First Nations peoples’ perspective on health and wellness, Beaudin²⁴ found that connectedness was experienced within the community between the community and the environment, and at the level of planet Earth. Participants spoke of being stewards of the land and how land contamination from landfill sites, and other environmental challenges, influenced individual’s and the community’s health: “That’s our connection to Mother Earth, it’s our medicines. So our health has a lot to do with it, of who we are and what we believe in … when something happens to the land, it will affect us too.”²⁴

In an Indigenous-led project, Smith et al. found that the Indigenous people of Central America and the Caribbean conceptualised health as a relationship with nature: “What the Maya present is an understanding of health and wellbeing that is attained via strong, reciprocal relationships with land, forests, plants and people − factors which are frequently absent within Western accounts of health.”³⁶

Systems thinking is characteristic of traditional knowledge as expressed by one of the participants in the study by Carrington et al.: “What’s happening is that the science is catching up to the mātauranga [traditional knowledge] Māori way of thinking… in that through whakapapa [genealogy], everything is connected, or maybe in the natural environment anyway. Things are connected.”³⁹

2.2: coming together

Traditional knowledge could have a role not only in environmental sustainability but in the way the research is conducted. Grande et al. argued for a participatory approach with Indigenous stakeholders, especially young people: “The results showed that capacity building and partnership between Indigenous and non-Indigenous communities at the systems and individual levels are critical in underpinning sustainable system-level change.”⁴⁰

Poland et al. related Indigenous methods (“talking circles”) to planetary health and to the ecological determinants of human health: “Recognising that problems cannot always be solved from the same level of thinking that created them, contemporary sustainability and social challenges are prodding us to look beyond conventional approaches to ‘greening’ business as usual … and to release the fiction that sustainability is a technical risk management problem, or even one of political will. In so doing, we create space to acknowledge the existence and relevance of alternative and hitherto marginalised worldviews, ways of knowing, and perspectives.”³³

Beaudin described the coming together of traditional and Western knowledge in an “ethical space” where there is common ground and mutual respect: “An ‘ethical space’ is a place where two worldviews come together.”²⁴ The “personal factors” component within the ICF “conceptual factors” component is ideally suited to assist in identifying potential areas where two worldviews intersect (i.e., an ethical space), and it would certainly be most beneficial to identify ethical spaces and potential solutions during the programme planning and service development stages related to healthcare. Traditional knowledge and voices should not only be incorporated into decision making but also into health-professional education, as explained by Brand et al.: “This change will ensure that health professionals, and others, are prepared to be environmental and human stewards of a healthy planet for all.”³⁸

Discussion

This systematic review shows that there is a small but growing interest in the nexus of traditional knowledge, healthcare and the environment. The two themes developed from our thematic synthesis are inter-related and claim that we in the health sector could widen our view of what constitutes wellbeing and broaden the ways in which we gain understanding. The two themes could be thought of as forming parts of a whole, in that a holistic concept of wellbeing gives direction to healthcare’s efforts while epistemological pluralism drives better understanding. Healthcare must learn through the diverse knowledge systems present in society; however, it is also important to avoid simply subsuming traditional knowledge, as explained by Redvers et al: “Traditional knowledges are not meant to be an assortment of information that can be simply merged with western scientific knowledge systems … traditional knowledges are collective, holistic, community-based, land-informed ways of knowing that are inherently interconnected with people and the environment … As such, they can be a source of knowledge for environmental strategic management in distinct ecosystems.”⁴⁴ Therefore, healthcare approaches should be grounded in Earth in general and in place-based local environments in particular.

The planetary health movement, which grew out of the environmental movements of the 1970s and 1980s,⁴⁵ recognises that “Human health and human civilisation depend on flourishing natural systems”.⁶ In 2018, the Canmore conference defined the principles of planetary health as: 1) the sustainable vitality of all systems, 2) values and purpose, 3) integration and unity, 4) narrative health, 5) planetary consciousness, 6) nature relatedness, 7) biopsychosocial interdependence, 8) advocacy, 9) countering elitism, social dominance and marginalisation, and 10) personal commitment to shaping new normative behaviours.⁴⁶ These principles could also be used to formulate a definition of human health.

The WHO defined health as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”.⁴⁷ Schramme argued that the word “complete” in the WHO definition of health should be interpreted as holistic, or “exhaustive of all constitutive features of well-being”⁴⁸—that is, physical, mental and social wellbeing. Schramme argued that interpreting the word “complete” to mean “perfect” health is problematic⁴⁸—can elderly people or those living with disabilities or chronic illnesses not also experience wellbeing? Redvers et al. modified the WHO definition to emphasise humans’ interconnectedness to nature: “Health is a state of dynamic balance within and between our physical, mental, social and spiritual well-being that is completely dependent on planetary health.”⁴⁹

Building on their definition of health, the WHO developed the ICF framework. Although relatively holistic in its approach, the present review found that the ICF misses a cultural dimension. This cultural dimension includes language, connectedness, traditional values, traditional medicines, cultural appropriateness of healthcare services, and environmental issues such as climate change; all of which are important determinants of health.²⁴ Other studies in our review emphasised the connection with nature, Mother Earth, land and country as central to the wellbeing of Indigenous peoples;^{20,26,28,34,38,44} therefore, although some health and economic organisations have come a long way,⁴⁶ they still need “a new set of values, which heed and privilege the wisdom of Indigenous worldviews, as well as a renewed sense of spirituality that can re-establish a reverence for nature”.⁸

A clue as to the way forward for healthcare lies in the second theme of the present study: epistemological pluralism. Epistemologically, Indigenous peoples use oral traditions, which represent collective knowledge acquired over thousands of years.⁵⁰ The concept of “two-eyed seeing” is a metaphor for many ways of knowing, a concept not only in the Indigenous literature but also debated in science studies literature. Orthia observed that: “Actions that steer the world towards a sustainable path must be rooted in science that is multidisciplinary, equitable and inclusive, openly shared and widely trusted, and socially robust.”⁵¹ Two examples of epistemological pluralism in Aotearoa New Zealand are Te Whare Tapa Whā⁵² and Rongoā Māori.⁵³ Te Whare Tapa Whā uses the metaphor of a meeting house to represent health: the four walls represent spiritual, mental, physical and family health respectively, and connection with the land (whenua) forms the foundation.⁵² Jenkins and Egger discussed Te Whare Tapa Whā in relation to how ecological restoration projects and Indigenous-led governance can promote public mental health.⁵⁴ The Rongoā Māori model encompasses spirituality, love (aroha), connections with the land, and herbal remedies.⁵³ The Aotearoa New Zealand health system introduced the Rongoā Māori Action Plan in 2024 to promote better health outcomes for Māori and non-Māori.⁵⁵ Recently, Rongoā Māori has been investigated in the public hospital surgical setting⁵⁶ and early results indicate a positive effect on patient care.⁵⁷

Our review indicates the need for more epistemological diversity in healthcare planning. DeShazo addressed the question of health disparities from the perspective of epistemological recalcitrance in health systems, concluding that alternative epistemologies could be a saving grace for healthcare: “By including a more diverse set of professionals, a diversity of tools can be added to the toolbox from which all healthcare professionals could draw.”⁵⁸ In this way, DeShazo operationalised the abstract concept of epistemology for healthcare: include diverse people of diverse knowledge systems in healthcare policy, planning and delivery. For example, in a collaborative project involving Māori health providers, regional district health boards and local iwi authorities, a cost-effectiveness analysis can be used to articulate both quantitative outcomes (such as reduced hospital admissions) and qualitative benefits (such as strengthened cultural identity). A recent report prepared for the Ministry of Health – Manatū Hauora recommended engaging “Māori leaders, healthcare providers, and communities in the planning and evaluation process (consistent with a Treaty partnership approach)”.⁵⁹ Internationally, Redvers et al. engaged with Indigenous elders in Canada’s circumpolar north to map out how to discuss health systems change.⁶⁰ Future research could follow a similar collaborative process.

Future research could also explore what constitutes health and wellbeing, perhaps in relation to specific groups such as children, the elderly, specific ethnic groups and certain socio-economic groups. Special attention should be applied to methods that adhere to the “ethical spaces” concept discussed in this review—that is, coming together on mutually respectful and equal footings. Research on national issues, such as how best to spend a limited health budget, is fundamentally societal and would benefit from diverse epistemological views. Other Indigenous health models that did not show up in the present review could be investigated—for example, the Fonofale model of health and wholeness of Pacific peoples, which could be explored in relation to connection to nature and to healthcare delivery.⁶¹

Limitations

The databases we searched cover the majority of health journals, but we may have missed relevant studies in the grey literature. The number of papers were small, most were qualitative, and quality scores were quite low for several papers, limiting generalisability. The choice of themes was a judgement call based on our purpose to inform health systems and the reflexivity of the research team, in keeping with our use of reflexive thematic analysis¹⁷ as a methodological basis. As noted by Redvers et al.: “Indigenous-specific land pedagogies are embedded directly within the respective lands stewarded by Indigenous peoples.”⁴⁴ Therefore, we need to be cautious about broad generalisations that remove the knowledge from its context. We hope the main points—holistic health conceptualisation and epistemological pluralism—are generalisable enough to overcome this limitation, particularly in relation to the consideration of diverse knowledge systems.

Conclusions

Literature on traditional knowledge as related to planetary health and healthcare remains under-explored, but it is gaining relevance. Healthcare systems in Western culture may benefit by adopting a broader, more inclusive definition of health that incorporates environmental stewardship and diverse cultural perspectives. The concept of health could extend the definition of the WHO charter by emphasising nature and the diversity of different cultures and localities. More research is needed on geographically specific, local Indigenous perspectives on healthcare and wellbeing. Locality-specific engagement with Indigenous communities and incorporating their knowledge into health-professional education is an important step towards creating a more sustainable and holistic healthcare system.

View Table 1, Figure 1.