Abstract
Background
Dementia is a clinical syndrome characterized by a progressive decline in cognitive abilities (e.g., memory loss) and abilities to engage in activities of daily life, and the presence of neuropsychiatric symptoms (e.g., depression) (e.g., (Grand et al., 2011)). Dementia may be caused by several types of neuropathology, however, it is most commonly associated with Alzheimer’s Disease and vascular disease (e.g., stroke) (Grand et al., 2011). Globally, dementia is the seventh leading cause of death and a major cause of disability and dependency among older adults (e.g., (World Health Organization, 2023)). The number of people living with dementia worldwide is estimated to triple from 50 million in 2020 to 152 million in 2050, driven primarily by population growth and aging (e.g., (Livingston et al., 2020)). The incidence of dementia is increasing more steadily among some Indigenous populations globally when compared to non-Indigenous peoples (Warren et al., 2015). For instance, research suggests that the prevalence of dementia will increase by 273% for Indigenous Peoples in Canada in 2050, compared to a 187% increase among non-Indigenous peoples (Alzheimer’s Society of Canada, 2024). This disproportionate increase has been theorized to be related to a growing number of older Indigenous Peoples (e.g., longer life expectancy), and broader social factors, such as colonization (Alzheimer’s Society of Canada, 2024). The current and projected number of Indigenous Peoples living with dementia necessitates approaches to reduce risk.
Indigenous Peoples in Canada, United States, New Zealand, and Australia
The United Nations (United Nations, 2024) identifies Indigenous Peoples as self-identified persons with a historical continuity with a given region prior to colonization and the arrival of settler societies, with a continued strong link to their lands/territories who maintain distinct social, economic, and political systems, languages, cultures, beliefs, and knowledge systems from the dominant society. Globally, there are approximately 370 million Indigenous Peoples across 70 countries, representing 5% of the global population (United Nations, 2024). Indigenous communities have considerable diversity in beliefs, values, practices, and traditions. However, several Indigenous populations, including Indigenous Peoples in Canada, the United States, Australia, and New Zealand, share a common experience of colonization, resulting in a loss of culture (e.g., cultural practices and connection to community) and changes to land-based relationships and stewardship, among other manifestations (e.g., (Warren et al., 2015)).
First Nations, Métis, and Inuit (FNMI) are the Indigenous nations in Canada recognized by the federal government. FNMI peoples comprise 5% of the Canadian population, with First Nations having the largest population (Statistics Canada, 2022). First Nations peoples may be at a higher risk for dementia than Métis and Inuit (Jacklin et al., 2012; Public Health Agency of Canada, 2021). In the United States, federally recognized Indigenous Peoples include American Indians, registered to tribal nations within the continental United States, and Alaska Natives, tribal nations and villages in Alaska, which make up approximately 1.9% of the United States population (United States Census Bureau, 2023). The age-adjusted prevalence of dementia is higher among American Indians than the general population (e.g., (Moon et al., 2023; Nguyen et al., 2024)). While other Indigenous nations in the United States, including Native Hawaiians, Chamorros, and American Samoans, are not federally recognized (Bureau of Indian Affairs, 2021), the prevalence and risk of dementia may also be higher among these communities when compared to non-Indigenous peoples (Mehta & Yeo, 2017; Smith et al., 2021).
The Indigenous population in Australia is primarily made up of two distinct cultural groups, Aboriginal and Torres Strait Pacific Islander peoples. In 2021, Aboriginal and Torres Strait Pacific Islanders comprised 3.2% of the Australian population and are predominantly Aboriginal (Australian Bureau of Statistics, 2022). The number of Aboriginal and Torres Strait Pacific Islanders aged 75 years and older is increasing, which may pose an increased risk of dementia cases in these Nations (Australian Bureau of Statistics, 2022). Indeed, the rates of dementia among Aboriginal and Torres Strait Pacific Islanders in Australia are estimated to be three to five times greater when compared to the general Australian population (Nguyen et al., 2024). Māori are the recognized Indigenous Peoples in New Zealand and comprise 17.3% of the New Zealand population (Stats NZ, 2023). Similar to other Indigenous Nations, the prevalence of dementia may be higher among Māori (Cheung et al., 2022). Given the high prevalence of dementia within Indigenous populations in these countries, it is critical to examine strategies to reduce risk.
Modifiable and Non-modifiable Risk Factors of Dementia
Dementia is associated with non-modifiable (e.g., genetics, sex, and age) and modifiable risk factors. These modifiable risk factors include, but are not limited to, low education, hearing loss, traumatic brain injury, hypertension, excessive alcohol consumption, obesity, smoking, depression, social isolation, physical inactivity, air pollution, and diabetes (Livingston et al., 2020). Previous research suggests that up to 40% of dementia cases can be prevented or delayed by reducing the presence of such modifiable risk factors (Livingston et al., 2020). In Canada, the incidence of dementia among some Indigenous peoples is primarily driven by similar modifiable risk factors (e.g., (MacDonald et al., 2015)). Modifiable risk factors are thus a primary target for risk reduction strategies (e.g., (Ngandu et al., 2015)). While interventions are being developed globally that address modifiable risk factors to reduce dementia risk, Indigenous and non-Indigenous researchers in Canada emphasize the need for culturally relevant approaches (Furlano & Walker, 2023).
Social Determinants of Health
Social determinants of health describe the conditions in which people live and work that influence health (Loppie & Wien, 2013). Several additional social determinants of health have been identified for Indigenous Peoples in Canada, such as colonization (e.g., colonial governance and Residential Schools), community infrastructure, resources and capacities, the education system, health activities, self-determination (e.g., authority over natural resources) and food insecurity (Loppie & Wien, 2013). Similar social determinants of health have been identified for Indigenous Peoples globally (e.g., racism and other colonial ideologies) (United Nations Economic and Social Council, 2023), and have been linked to the modifiable risk factors of dementia (e.g., (Henderson et al., 2024)). It is plausible that these social determinants of health are critically linked to many of the modifiable risk factors of dementia.
Culture encompasses all the aspects of a way of life that are passed down socially, including values, knowledge, behaviors, and practices (Kirmayer et al., 2021). Culture (e.g., language, sacred practices, land-based practices, connection to community, and spirituality) is an international Indigenous social determinant of health (United Nations Economic and Social Council, 2023). Cultural resurgence speaks to the reclamation and re-engagement of Indigenous languages, traditions, values, relationships, governance, and relationships to lands and waters (e.g., (Loppie & Wien, 2013)). In a landmark study, cultural continuity was associated with an absence or reduced rates of suicide among many First Nations communities in Canada (Chandler & Lalonde, 1998). Connection to culture has also been associated with a lower prevalence of health conditions among Indigenous Peoples in Canada, the United States, Australia, and New Zealand (e.g., (Bourke et al., 2018)). Accordingly, it is plausible that connection to culture may help to reduce the prevalence of modifiable risk factors of dementia among Indigenous Peoples. Indeed, recent research suggests that connection to culture may be a protective factor for dementia for global Indigenous Peoples (Nguyen et al., 2024). However, as of November 2023, no reviews summarize this information for Indigenous Peoples in Canada, the United States, Australia, and New Zealand.
Sex and Gender Considerations
Dementia is typically more common among females among the general population (Alzheimer’s Society of Canada, 2024). Sex-based differences in dementia prevalence may be due to differences in life expectancy, genetic risk factors, hormones, cumulative androgen deprivation therapy (e.g., for use during prostate cancer), and differences in the prevalence of modifiable risk factors, such as cardiovascular risk factors (Alzheimer’s Society of Canada, 2024). In contrast, dementia is more prevalent among males within some Indigenous populations, such as Canada and Australia (Walker et al., 2020), but not others (e.g., (Nguyen et al., 2024)). Sex and gender may also influence the strength and characteristics of the association between connection to culture (e.g., engagement in cultural practices) and modifiable risk factors for dementia. For instance, Indigenous women in the United States report higher levels of enculturation, and acculturation is associated with alcohol and drug use in response to stress among males (Burnette et al., 2020).
Gender also plays a role in understanding the risk for dementia. For instance, certain modifiable risk factors, such as low education, may impact women more heavily, given historical and present inequalities in access to education (Alzheimer’s Society of Canada, 2024). Transgender and non-binary adults may be at a higher late-life risk for dementia when compared to cis-gendered adults, potentially due to higher stigma and discrimination (Brady et al., 2024). The experiences of dementia among transgender, non-binary, and Two-Spirit Indigenous Peoples may be markedly different than cis-gendered individuals (Adan et al., 2021).
While a sex and gender analysis may be useful to understand the risk of dementia, as of November 2023, no reviews have examined the association between connection to culture and the modifiable risk factors using a sex and gender analysis among Indigenous populations in Canada, the United States, Australia, and New Zealand. If certain cultural practices are more strongly associated with modifiable dementia risk factors, such as physical activity, depending on sex and gender, this would have important implications for informing prevention efforts.
The Current Study
Despite evidence suggesting a key role in connection to culture (e.g., cultural practices and connection to community) and the modifiable risk factors for dementia, as of November 2023, there are no existing reviews that summarize the literature on connection to culture and the major modifiable risk factors of dementia for Indigenous Peoples, nor are there any reviews that evaluate differences in the characteristics and strength of this relationship based on sex and gender. Further, there is a lack of research that summarizes how sex and gender have been characterized within this literature (e.g., terminology used when describing sex). A scoping review of the literature that examines the connection to culture and the modifiable risk factors of dementia, using a sex and gender analysis, may help inform dementia prevention and health promotion initiatives within Indigenous communities and inform local government public policy.
Research with Indigenous communities has a history of exploitation and the production of research that has not been respectful and relevant to participating communities (Huria et al., 2019; Smith, 1999). Among other efforts to rectify these past and in some cases, ongoing injustices, reporting guidelines may help to improve the quality of research and health outcomes for Indigenous communities (Huria et al., 2019). The consolidated criteria for strengthening the reporting of health research involving Indigenous Peoples (CONSIDER) statement was created to improve research practices, research conduct, and dissemination to improve health equity for Indigenous Peoples (Huria et al., 2019). Utilizing the CONSIDER statement when evaluating Indigenous research may help to inform the quality of the research from an Indigenous perspective.
Review Objectives
The objective of this scoping review is to identify and synthesize the available literature on the relationship between connection to culture and the incidence of modifiable risk factors for dementia among Indigenous Peoples in Canada, the United States, Australia, and New Zealand. We aim to: ● Identify the available research on the association between connection to culture (e.g., cultural practices and connection to community) and the modifiable risk factors of physical activity, education, alcohol, smoking, obesity, type 2 diabetes, and hypertension among FNMI, American Indians, Alaska Natives, Native Hawaiians, Chamorros, and American Samoans, Aboriginal and Torres Strait Pacific Islanders, and Māori. ● Examine how research in this area reports sex and gender, and how the association of connection to culture and the modifiable risk factors of dementia is influenced by sex and gender. ● Evaluate the quality of published studies utilizing the CONSIDER statement (Burnette et al., 2020).
Method
The proposed scoping review will follow the 2020 Joanna Briggs Institute (JBI) methodology for scoping reviews (Smith, 1999). The review protocol has been pre-registered on the Open Science Framework database (https://osf.io/3ykdr). The idea of the proposed protocol was conceptualized by the first author (B.S.) while conducting the literature review for her M.A. research, supervised by co-author C.M. The scoping review methodology and search strategy was developed by the lead author with an experienced librarian at Lakehead University in Thunder Bay, Ontario, Canada. The remaining co-authors are involved in reviewing articles, data extraction, summarizing results, and preparing the scoping review manuscript.
Self-location is a critical component of Indigenous research (Kovach, 2009). This review will be conducted by Michi Saagig Nishnaabe (B.S.), Anishinawbe (Ojibway) (C.M.), and non-Indigenous allied health researchers (A.A., I.M., H.S., and E.T.).
Eligibility Criteria
Populations
We will include studies that focus on Indigenous Peoples in Canada (FNMI), the United States (American Indians, Alaska Natives, Native Hawaiians, Chamorros, and American Samoans), Australia (Aboriginal and Torres Strait Pacific Islander), and New Zealand (Māori). While there are many Indigenous nations globally, we have chosen to focus on these nations due to similar experiences of colonization and reported impacts on health (Nguyen et al., 2024). Articles will be included that have individuals from any age, gender, and sex.
Concept
This review will include studies that examine the association between connection to culture and the primary modifiable risk factors of dementia of physical inactivity, low education, excessive alcohol consumption, tobacco smoking, obesity, type 2 diabetes, and hypertension. These modifiable risk factors were selected based on previous research conducted with the global population, and Indigenous Peoples more specifically (Livingston et al., 2020; MacDonald et al., 2015).
Connection to culture is challenging to define across multiple and highly diverse Indigenous nations. Moreover, it is important to respect the contemporary experience of cultural identities and how expressions of culture may differ across and within generations. In this review, we used a broad construct definition of connection to culture in the search strategy. Within the search strategy, connection to culture included any articles that described or explicitly listed a connection to culture, cultural continuity, cultural identity, language, cultural practices, community support, social support, sense of community and community belonging, traditional practices and modern expressions, traditional diets (e.g., wild foods), storytelling, dance (e.g., powwows), Indigenous sports (e.g., lacrosse), weaving, carving, and plant medicines.
Context
The scoping review will include studies from Canada, the United States, Australia, and New Zealand.
Types of Sources
This scoping review will draw on quantitative (e.g., experimental and correlational designs) and qualitative (e.g., interviews and focus groups) peer-reviewed studies, and gray literature (e.g., Indigenous databases and dissertations). For quantitative data, we will accept all types of outcome measures (standardized and unstandardized). Literature reviews (e.g., systematic and scoping reviews), conference abstracts, commentaries, and book chapters will not be utilized. We will conduct a hand-search of all included articles’ reference lists to identify additional relevant articles.
Search Strategy
PsychInfo Literature Search Strategy.
Study/Source Evidence Selection
In February 2024, we uploaded all articles to Rayyan software (
Data Extraction
Data Extraction Table.
Data Analysis and Presentation
We will extract the data to examine and summarize the research on the connection to culture (e.g., cultural practices and connection to community) and modifiable risk factors of dementia (e.g., low education) among Indigenous Peoples in Canada, the United States, Australia, and New Zealand. We will summarize relevant participant demographics (e.g., sex and gender), highlight sex and gender-based differences and conceptualizations, and evaluate the articles using the CONSIDER statement. We will summarize the data using a narrative synthesis, tables, and charts. The results will be reported using PRISMA-ScR (Tricco et al., 2018).
Discussion
Research suggests that connection to culture for Indigenous Peoples may reduce the incidence and prevalence of the modifiable risk factors for dementia (e.g., (Bourke et al., 2018; Nguyen et al., 2024)). To date, a comprehensive review of the literature examining this relationship among Indigenous Peoples has not been conducted. Using a broad construct definition of culture, this scoping review will identify and summarize the published research exploring the relationship between connection to culture and modifiable risk factors for dementia among Indigenous Peoples in Canada, the United States, Australia, and New Zealand. Using the CONSIDER statement, we will evaluate the quality of published literature in this area. Additionally, we will examine how sex and gender-based considerations influence the association between connection to culture and major modifiable risk factors of dementia, and evaluate how sex and gender has been conceptualized in previous research.
The results of this review will provide a nuanced understanding of how Indigenous culture influences the modifiable risk factors for dementia. The review may help to identify specific cultural practices that more greatly influence modifiable risk factors of dementia. The review may also help to identify if the strength and characteristics of the association between connection to culture (e.g., cultural practices) and modifiable risk factors vary as a function of sex and gender. Results may also inform Indigenous health research more broadly by clarifying how culture is operationalized in the current literature.
Findings may inform researchers, clinicians, health promotion initiatives, and public policy on the importance, process, and best practices for developing culturally-relevant dementia prevention programs. Results will also identify essential research gaps and needs, which may help to inform future research. We will disseminate results through a peer-reviewed journal publication, academic conferences, and community-based presentations.
Footnotes
Author Contributions
Author B.S. was responsible for the review conceptualization, development of the methodology, and literature search. Authors B.S., A.A., I.M., and H.S. all contributed equally to reviewing and selecting the included articles for this review. Authors A.A. and I.M. composed the abstract. Author A.A. composed declarations sections and assisted with paper formatting. Authors B.S., I.M., and H.S. helped to compose the discussion section. Author B.S. composed the introduction and methods sections. C.M. and E.T. provided supervision and direction on the conceptualization and methodology. All authors contributed equally to the final editing, review, and approval of the manuscript.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
