Background

We all hope to maintain our brain health and live an active and cognitively engaged life as we age.

However, advanced age is associated with cognitive decline and increased risk of cognitive impairment and dementia. Yet there is significant individual variability in both level and slope of cognitive and brain aging trajectories. Indeed, currently there exist health inequities, i.e., increased prevalence of cognitive impairment and dementia, based on sex, gender, race, and ethnicity. For example, two-thirds of older adults diagnosed with AD are females. Yet, we know little about why this sex difference in AD prevalence exists and whether it is due to female biological sex, the gendered life experiences of women and/or the interaction of sex and gender. In addition, in North America, disparities in some social and structural determinants of health (SSDH, e.g., education, poverty, poor diet) are linked to poorer aging trajectories and increased dementia risk in some communities that have been historically excluded from research.

However, advanced age is associated with cognitive decline and increased risk of cognitive impairment and dementia. Yet there is significant individual variability in both level and slope of cognitive and brain aging trajectories. Indeed, currently there exist health inequities, i.e., increased prevalence of cognitive impairment and dementia, based on sex, gender, race, and ethnicity. For example, two-thirds of older adults diagnosed with AD are females. Yet, we know little about why this sex difference in AD prevalence exists and whether it is due to female biological sex, the gendered life experiences of women and/or the interaction of sex and gender. In addition, in North America, disparities in some social and structural determinants of health (SSDH, e.g., education, poverty, poor diet) are linked to poorer aging trajectories and increased dementia risk in some communities that have been historically excluded from research.

It has been proposed that the observed variabilities and inequities in cognitive and brain aging trajectories reflect individual differences in biology, life experiences, and lifestyle choices.

A framework for understanding individual variability in aging trajectories has been proposed by the National Institutes of Health (USA) Collaboratory on Research Definitions for Reserve and Resilience in Cognitive Aging and Dementia. In this framework, resilience is characterized as a general term that subsumes three concepts and mechanisms that support one’s ability to maintain effective levels of cognition and brain function with aging: i) brain reserve, defined as the neurobiological status of individual’s brain structure that is relevant to cognition; ii) brain maintenance, defined as individual differences in the ability to resist to age-related neurodegeneration and aggregation of dementia-related neuropathology, e.g., amyloid plaques and tangles in the case of Alzheimer’s disease (AD); and iii) cognitive reserve, defined as individual differences in the ability to maintain cognition and brain function in the presence of age- or AD-related brain changes. Notably, all aspects of resilience can be influenced by sex, gender, and differential exposures to enriching or detrimental life experiences and SSDH. Systematic patterns of such differential exposures may underlie the health inequities observed in cognitive aging and dementia prevalence. However, it remains unclear what environmental, social, and biological factors support or hinder one’s brain resilience, and if these factors are the same across historically marginalized communities (diversity), females and males (sex), and across genders. This paucity of knowledge is problematic to the development of more inclusive and precise models of cognitive and brain aging trajectories representative of Canada’s diverse aging community.

A framework for understanding individual variability in aging trajectories has been proposed by the National Institutes of Health (USA) Collaboratory on Research Definitions for Reserve and Resilience in Cognitive Aging and Dementia. In this framework, resilience is characterized as a general term that subsumes three concepts and mechanisms that support one’s ability to maintain effective levels of cognition and brain function with aging: i) brain reserve, defined as the neurobiological status of individual’s brain structure that is relevant to cognition; ii) brain maintenance, defined as individual differences in the ability to resist to age-related neurodegeneration and aggregation of dementia-related neuropathology, e.g., amyloid plaques and tangles in the case of Alzheimer’s disease (AD); and iii) cognitive reserve, defined as individual differences in the ability to maintain cognition and brain function in the presence of age- or AD-related brain changes. Notably, all aspects of resilience can be influenced by sex, gender, and differential exposures to enriching or detrimental life experiences and SSDH. Systematic patterns of such differential exposures may underlie the health inequities observed in cognitive aging and dementia prevalence. However, it remains unclear what environmental, social, and biological factors support or hinder one’s brain resilience, and if these factors are the same across historically marginalized communities (diversity), females and males (sex), and across genders. This paucity of knowledge is problematic to the development of more inclusive and precise models of cognitive and brain aging trajectories representative of Canada’s diverse aging community.

This Collaboratory was formed to address this knowledge gap, with the awareness that addressing health equity and inclusion in research on aging and dementia requires the integration of research questions, theories, methodologies, and applications from complementary research fields, including cognitive and clinical neuroscience, geriatrics, neurology, biology, epidemiology, computational neuroscience, sex and gender science, as well as sociology and other cultural and social sciences. In addition to academic input, addressing this problem also requires the input and experiences of i) Knowledge Users with direct connections to diverse community-dwelling older adults and influence on research and healthcare policy and priorities; and ii) Persons with Lived Experiences (PWLE), including persons with dementias and carers.

This Collaboratory was formed to address this knowledge gap, with the awareness that addressing health equity and inclusion in research on aging and dementia requires the integration of research questions, theories, methodologies, and applications from complementary research fields, including cognitive and clinical neuroscience, geriatrics, neurology, biology, epidemiology, computational neuroscience, sex and gender science, as well as sociology and other cultural and social sciences. In addition to academic input, addressing this problem also requires the input and experiences of i) Knowledge Users with direct connections to diverse community-dwelling older adults and influence on research and healthcare policy and priorities; and ii) Persons with Lived Experiences (PWLE), including persons with dementias and carers.