The Many Faces of Dementia
REPRESENTING DIVERSE SAMPLES IN DEMENTIA RESEARCH.
Much of our current health data and treatment strategies for dementia have been based on samples from older, white people, and may not reflect the realities, supports, and cultural considerations for diverse people with dementia.
According to the Alzheimer Society of Canada’s 2024 report, “The Many Faces of Dementia in Canada,” there is a pressing need to raise awareness that people of all ethnic and racial groups may develop dementia. With age as the largest risk factor for dementia, as the ethnocultural demographics of older adults shifts in Canada and other countries with high levels of immigration, these demographic changes will be reflected in populations living with dementia.
Ensuring that diverse samples are represented in future dementia research is critical to enhancing our knowledge of the disease and developing appropriate services and supports.
WEIRD SAMPLING
Lack of diversity in health science and behavioural science sampling is not a new issue. In a 2010 article published in Behavioral and Brain Sciences, Drs. Joseph Henrich, Stephen Heine, and Ara Norenzayan from the University of British Columbia coined the tongue-in-cheek acronym “WEIRD” to refer to research samples comprised of university undergraduates from Western (primarily white), Educated, Industrialized, Rich, and Democratic countries.
The authors examined research sampling practices in top-cited academic journals and found that scientific knowledge of human psychology has been largely based on WEIRD “convenience” samples, primarily from American universities.
Through a comparative analysis of findings from WEIRD samples to other samples (e.g., non-Western samples, non-university-educated Americans), Henrich et al. provided compelling evidence that “WEIRD subjects are particularly unusual compared with the rest of the species – frequent outliers.”
It followed that broad claims about human nature made from WEIRD samples could not hold up across diverse populations.
The authors challenged researchers to identify creative ways to include diverse samples in their work so that findings could be generalized across populations.
Another issue raised by Henrich and colleagues was that the researchers themselves who published in top-cited journals tended to be WEIRD, which influenced the types of issues that they investigated and their scientific approaches.
In a 2024 symposium organized by the Brain Resilience and Diversity in Aging and Dementia Collaboratory in Montreal, Dr. Karen Campbell, Canada Research Chair in Cognitive Neuroscience of Aging at Brock University, explained,
“WEIRD samples collected by WEIRD labs leads to WEIRD results, and a lack of understanding of how different groups of people experience (phenomena like) aging.”
Although the influential article by Henrich and his team has been cited more than 14,000 times, unrepresentative WEIRD samples and WEIRD research labs continue to hinder our understanding of human behaviour and the brain, said Dr. Campbell. One solution is to create more opportunities for trainees from diverse cultures who will then go on to become principal investigators and bring new perspectives to the research world.
Diverse research labs may also help to devise new participant recruitment strategies, build trusting relationships with under-represented groups, and minimize perceptions of stereotype threat, i.e., the fear of confirming negative stereotypes about one’s group.
In Dr. Campbell’s experience, recruitment methods and researcher mistrust are among the reasons why participants who opt into studies tend to be highly educated and relatively wealthy. Taking time to connect and consult with historically marginalized and racialized communities throughout the research process will assist in identifying questions that are relevant to broader populations, lead to findings that apply to a wider range of groups, and subsequently create recommendations that are useful and feasible to implement in more communities.
MANY FACES OF DEMENTIA
With more immigration than ever before, countries around the world are increasingly ethnically and racially diverse, and this diversity is starting to be reflected in dementia research. A cohort study by Dr. Shiekh and colleagues in 2020 examined the onset and frequency of dementia among global racialized populations.
Published in Journal of Epidemiology & Community Health, this report showed that there were significant differences in dementia risk between racial and ethnic groups, with the highest incidence reported among Black groups, similar incidence rates for Latin and white groups, and the lowest rates among Asian groups.
While some of this increased risk for dementia among Black groups related to higher rates of hypertension and diabetes, which are major risk factors for dementia, social inequalities also contributed to disease risk.
In a follow-up review published in Journal of Alzheimer’s Disease in 2021, Dr. Shiekh and his team explained that inequalities in care seeking, likelihood of diagnosis, and uptake of treatments contributed to ethnic differences in dementia.
A 2011 systematic review published in International Journal of Geriatric Psychiatry, Drs. Mukadam, Cooper, and Livingston examined why people from minority ethnic groups tend to seek care at later stages, once dementia has progressed toward moderate or severe stages.
Among the reasons for delays in seeking care were fear of shame and stigma within the community, not knowing that treatment options were available, believing that dementia was normal in the course of aging, negative experiences with healthcare providers, and believing that care was a family responsibility.
As clinicians rely on individuals and care partners to report symptoms and potential problems, if such information is not shared during medical visits, this can delay access to supports.
The authors concluded that there are real barriers for seeking help in minority ethnic groups, and more research is needed to examine the role of ethnicity and culture, and to identify when and where prevention efforts should be focused.
Ongoing research by the Canadian Centre for Economic Analysis (CANCEA) on behalf of the Alzheimer Society of Canada is helping to fill knowledge gaps on racially diverse communities and dementia.
CANCEA created the Landmark Study to examine how sociodemographic factors, like ethnic and racial diversity, impact people affected by dementia and influence the course of disease. The Landmark Study uses a microsimulation model to predict the proportion and characteristics of people who will be affected by dementia over the next 30 years.
By modelling the characteristics of those who will be affected by dementia, researchers hope to better understand and prepare healthcare systems to meet the needs of culturally and ethnically diverse populations.
In 2022, the first report based on the Landmark Study showed that by 2050, we will have 1.7 million Canadians living with dementia, which is almost three times the number in 2020. With age as the strongest predictor of dementia, the three-fold increase is largely related to the growing number of older adults.
We will need tools for early diagnosis to increase the utility of interventions, strategies to mitigate the effects of dementia, and capacity to address the increased demand in services.
The second report published in 2024 was titled “The Many Faces of Dementia in Canada” and predicted that the changing ethnic and racial makeup of the population will also be reflected in the rates of dementia, with the largest increase projected for people of Asian ancestry, followed by increases in people with Indigenous, Caribbean, or African ethnic origins.
Emerging research cited in the report showed that differences in biological markers (biomarkers) found in certain racialized populations may contribute to the incidence of dementia.
For example, the Apolipoprotein epsilon 4 gene has been linked to risk of late onset Alzheimer’s dementia. Higher rates of this gene have been reported among Black populations when compared to white populations, while the latter group has higher rates of having the gene present than Asian and Latin American populations.
While genetic risk factors are largely beyond our control, the report also identified disparities in modifiable risk factors and social determinants of health as key drivers of dementia in racialized populations.
Dr. Ingrid Waldron, the HOPE Chair in Peace and Health in the Global Peace and Social Justice Program at McMaster University in Hamilton, Ontario, explains, “While there are genetic components to the development and progression of dementia, social determinants, like under education, unemployment, racism, food insecurity, and housing insecurity can lead to health disparities between racialized communities (like Black communities) and white communities more so than biology or genetics.”
These health disparities in turn lead to higher rates of comorbid diseases like hypertension and diabetes, and an increase in potentially preventable dementia cases. It is therefore expected that addressing social determinants of health can create more equitable conditions for racialized communities and delay or reduce the incidence of dementia in these groups.
EXPERIENCES OF BLACK CANADIANS WITH DEMENTIA & THEIR CARE PARTNERS
Dr. Waldon’s research broadly examines the social determinants of health in Black, Indigenous, immigrant, and refugee communities. Her specific interest in dementia experiences stems from personal experience as a Black woman and a family care partner for her mother with Alzheimer’s dementia.
“We have had dementia in Black communities for years, but many of us didn’t know what it was. We didn’t have a name for the behaviours characterized by dementia, like wandering and becoming less communicative, and previous generations did not receive an official diagnosis.”
In addition to limited knowledge on dementia in racially diverse communities in Canada, Dr. Waldron discovered that there is also limited research available on dementia experiences – of both patient and care partner – and their respective needs within Black and other racialized communities. This has hindered the creation of culturally tailored supports and services.
In an effort to explore intersections of race and dementia, Dr. Waldron convened a team of researchers to study 12 Black Canadian care recipients living with dementia and their respective care partners. Participants took part in interviews, and findings were published in a 2024 report called “The Experiences of Black Canadians Living with Dementia in the Greater Toronto and Hamilton Area and their Care Partners in Providing Care”
When asked about perceptions of cultural competency among their healthcare workers, many interviewees felt that the care they received was culturally competent, though care recipients wished to see more representation of Black people.
“Participants explained that it would have been preferable if their physician or other support workers were Black,” said Dr. Waldron, and could understand where the care recipients were coming from.
Participants also shared some ideas on what culturally tailored supports and services could look like. As many care partners were relatives, they suggested that intergenerational programming activities would be ideal to strengthen relationships and improve well-being for everyone involved.
Participants were keen to learn more about how to live better and what to do to alleviate dementia symptoms. “We need to start talking about dementia and making positive changes in our lifestyle. There are things you can actually change to reduce your risk of dementia, such as improving diet and increasing exercise to prevent obesity, and stopping smoking,” explained Dr. Waldron.
“Whatever we can do in terms of prevention and leading healthy lifestyles, we should be doing.”
As part of future applications, the research team will devise health promotion strategies for Black communities, including creating digital resources featuring Black individuals.
“Statistics show that more and more of us will get dementia, like Alzheimer’s, and it will primarily impact women. I want Black women to take dementia seriously and be able to understand the risk factors and get information on modifiable lifestyle factors to prevent this disease. I want Black women to know that there is no shame in having or talking about dementia. We need to become more aware and less dismissive,” hopes Dr. Waldron.
Source: Mind Over Matter V19