Researchers can now submit applications to access the first baseline data release from the Healthy Brains, Healthy Aging (HBHA) Initiative, marking a major milestone for brain health and healthy aging research in Canada and internationally. The HBHA Initiative, a substudy of the Canadian Longitudinal Study on Aging (CLSA), was established with support from the Weston Family Foundation to strengthen the CLSA as a world-leading platform for understanding cognitive aging and the factors that promote lifelong brain health.
The first HBHA data release includes baseline stool microbiome (metagenomic) data from nearly 6,000 participants, including approximately 2,400 participants who also completed brain MRI scans and cognitive assessments. At the same time, new core CLSA Follow-up 3 data, including sleep tracker data, are being released, providing additional information that can be linked with the HBHA data. Together with the CLSA’s extensive health, biological, social, lifestyle, and environmental data, these measures provide researchers with new opportunities to investigate the biological, behavioural, and environmental factors associated with brain health and cognitive aging.
The brain imaging data provide detailed measures of brain health, including brain structure, white matter integrity, and markers of neurodegeneration. These measures can be examined alongside the extensive health, biological, social, lifestyle, and environmental information already collected through the CLSA, supporting research into factors associated with healthy cognitive aging, brain and cognitive reserve. Future HBHA data releases will include stool metabolomics data and additional MRI measures including cerebral blood flow through arterial spin labelling, brain iron accumulation through quantitative susceptibility mapping, and white matter microstructure and myelin integrity through diffusion imaging and myelin water fraction.
Importantly, the HBHA Initiative is designed to support research on how these relationships evolve over time. Approximately three years after their baseline assessment, participants are being invited to complete the same HBHA assessments, including brain MRI, cognitive assessments, and stool collection. The resulting follow-up data will provide an opportunity to examine changes in brain health, cognition, and the gut microbiome within the same participants and to investigate factors associated with resilience and decline over time.
“The HBHA Initiative was established to elevate the CLSA as a globally significant resource for understanding healthy aging and the aging brain. This first data release lays the groundwork for transformative research, offering insights that will become increasingly powerful as future waves of data reveal how health and aging evolve over time.”
— Christian Bauta, Chair of the Weston Family Foundation
“The Healthy Brains, Healthy Aging study represents an important evolution of the Canadian Longitudinal Study on Aging. By embedding this work within the CLSA, we can build on more than a decade of deeply characterized health, social, lifestyle and biological data to understand why some people maintain their brain health as they age while others experience decline. By adding advanced brain imaging, sleep, mobility, biological and other measures, we can connect what is happening in the brain with what has been happening in people’s lives over many years. Ultimately, our goal is not simply to understand brain aging, but to identify factors that can be modified so that more Canadians can maintain their cognitive function, independence and quality of life as they grow older.”
— Parminder Raina, Principal Investigator, CLSA and HBHA Initiative
By bringing together these diverse data types within a nationally representative longitudinal cohort, the HBHA Initiative enables research that would not be possible using microbiome, neuroimaging, or cognitive datasets alone. The result is a powerful new resource for advancing discoveries that could improve brain health across the lifespan.
Researchers in Canada and internationally can apply to access the HBHA data through the CLSA’s established data access process. Please note: The next data access application submission deadline is Wednesday, October 7, 2026 (5 p.m. Eastern).
