Mobility and sleep tracker data are not included in HBHA datasets. Researchers wishing to access wearable device data must select “Physical Assessment” under the Core CLSA Data in Part 2 (Data Checklist) of their data access application. Follow-up 3 physical assessment data will be available for researchers to access beginning in October 2026.
A Platform for Brain Health Research
As the population ages, there is a critical need to understand the
determinants of successful cognitive aging such as physical activity,
sedentary behaviour, diet and sleep using large-scale, population-based methods. The CLSA is an ideal research platform to advance this understanding through its longitudinal design, inclusion of adults from mid-life to older age, and its comprehensive collection of questionnaire data, physical assessments, and biological specimens. The CLSA-Weston Healthy Brains, Healthy Aging (HBHA) Initiative will further develop the CLSA as a global platform for research on cognitive aging with the introduction of neuroimaging, gut microbiome analyses and enhanced lifestyle measures.
CLSA-Weston HBHA Initiative
Since 2021, the Canadian Longitudinal Study on Aging has received more than $13 million in research funding from the Weston Family Foundation to establish the CLSA-Weston Healthy Brains, Healthy Aging Initiative. As a result of this funding, the CLSA introduced brain imaging (MRI scans), stool sample collection and additional cognitive measures. These data are combined with existing CLSA measures of physical and cognitive health, medical, psychosocial, socioeconomic, environment, lifestyle, and biospecimens to critically advance fundamental knowledge regarding successful cognitive aging. The introduction of the CLSA-Weston HBHA Initiative provides a unique opportunity to address research on the aging brain from a multisystem approach that requires data from cell to society.
HBHA Data Collection
Launched in 2022, the CLSA-Weston HBHA Initiative includes 6,051 participants from the CLSA Comprehensive Cohort. Of these participants, 6,041 provided stool samples for microbiome and metabolomic profiling.
A subset of 2,373 participants completed structural and functional brain MRI and three cognitive tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Both MRI and stool sample data are available for 2,263 participants.
HBHA participants were invited to wear mobility trackers to enable the measurement of physical activity and mobility. Participants invited to complete the MRI protocol were also offered sleep trackers to enable the assessment of sleep patterns. Stool samples were collected at all 11 sites. Structural and functional MRI data were collected at eight sites with MRI facilities that met the study protocol requirements.
Follow-up HBHA data collection began in April 2025 during Follow-up 4 and will continue through 2028.
Data Access and Data Availability
Researchers can submit new applications for Baseline HBHA data beginning in October 2026 through the CLSA data access process. Due to the nature of the data, amendments to existing data access applications will not be accepted.
As of October 2026, baseline HBHA alphanumeric data are available, including stool microbiome profiles, MRI-derived data including measures of global and regional brain volumes and cortical thicknesses; volume of white matter hyperintensities, and presence and location radiologic markers of cerebrovascular disease and neurodegeneration, and three cognitive tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB). MRI image files, and derived MRI measures including cerebral blood flow through arterial spin labelling, brain iron accumulation through quantitative susceptibility mapping, measures of microstructural white matter changes through diffusion imaging and myelin water imaging, and resting state connectivity are not available at this time.
The HBHA data release does not include mobility and sleep tracker data. Data collected from wearable devices will be integrated into data releases of Core CLSA physical assessments, expanding the range of measures available to researchers. Follow-up 3 physical assessment data will be available for researchers to access beginning in October 2026.
Frequently Asked Questions
Find answers to some of the most common queries about the CLSA
As of October 2026, baseline HBHA alphanumeric data are available, including stool microbiome profiles, MRI-derived data including measures of global and regional brain volumes and cortical thicknesses; volume of white matter hyperintense lesions, and presence and location of radiologic markers of cerebrovascular disease and neurodegeneration, and three cognitive tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB). MRI image files, and derived MRI measures including cerebral blood flow through arterial spin labelling, brain iron accumulation through quantitative susceptibility mapping, and measures of microstructural white matter changes through diffusion imaging and myelin water imaging are not available at this time.
Graduate students (Masters or PhD) enrolled at Canadian universities who wish to obtain the CLSA data for the sole purpose of their thesis, and postdoctoral or clinical fellows (limit 1 waiver per fellow) who wish to obtain the CLSA data for the sole purpose of their postdoctoral project, may request a fee waiver. This fee waiver only applies to alphanumeric data. Any additional data requested, such as images and raw data, have associated fees. The trainee fee waiver cannot be applied to CIHR catalyst grant applications. Canadian trainees working outside Canada but funded through a Canadian source are also eligible for a fee waiver.
Researchers should review the Data Availability Table, Data Dictionaries, and Researcher Resources sections.
Applicants should plan on receiving data six months after the submission deadline. For more information, visit Data Access.
No. Only new applications will be accepted for HBHA data.
Researchers must submit new applications to access HBHA data. The standard CLSA data access fee is $4,000 for researchers within Canada, and $10,000 USD for researchers outside Canada. Depending on the data requested as part of the application, additional fees apply for access to image files, raw data and datasets that require more complex customization.
Research Team
Research Funding
Support for the study is provided through the Canadian Institutes of Health Research and the Canada Foundation for Innovation. The introduction of brain imaging and gut microbiome analyses into the CLSA has been generously supported by the Weston Family Foundation.
