A major 13-year study of older Australians has found that the neighbourhoods we live in may play a critical role in protecting brain health and slowing memory decline.
The research, led by the Centre for Healthy Brain Ageing (CHeBA) at UNSW Sydney in collaboration with the Australian Catholic University (ACU), followed more than 1,000 adults aged over 70 as part of the Sydney Memory and Ageing Study (MAS), one of Australia’s longest-running investigations into ageing and brain health.
Results, published in Alzheimer’s and Dementia, suggest that living in walkable, green, and well-connected neighbourhoods — particularly those with access to public transport, commercial services, and parklands — may reduce the risk of dementia and even promote recovery from mild cognitive impairment.
Conversely, living in areas with high air pollution, especially fine particulate matter (PM2.5), was linked to faster cognitive decline.
“What’s exciting about this research is that it confirms the environment you live in isn’t just a backdrop to healthy ageing – it’s a key ingredient,” said Professor Ester Cerin, lead author from ACU and founder of the International Cognitive Health and the Environment Network (ICHEN).
“Supportive neighbourhoods that encourage activity, reduce stress, and offer better air quality appear to help protect the ageing brain.
“This study builds on similar findings from other research contributing to ICHEN on the impact of environmental exposures on cognition and is particularly important as it is based on rigorous cognitive assessments across a long period of time.”
Notably, researchers found that access to public transport, green space, and coastal or blue space was associated with a higher likelihood of cognitive recovery.
“This is a hopeful message,” said Dr Annabel Matison, Post-Doctoral Research Fellow at CHeBA.
“Even in later life, living in the right environment can offer a second chance for cognitive improvement — not just delay deterioration.”
The findings highlight the potential for urban planning and public health policy to contribute directly to population-wide brain health outcomes, particularly as dementia rates climb globally.
CHeBA Co-Directors and MAS founding investigators, Professor Perminder Sachdev and Professor Henry Brodaty, emphasised the significance of the long-term research effort.
“When we began MAS in 2005, we aimed to understand why some people maintain cognitive function while others decline,” Professor Sachdev said.
“This new analysis gives us deeper insight into how the built and natural environments play a role.”
Following the success of MAS, researchers launched a second phase — the MAS2 study — in 2023.
This new cohort will examine how education, healthcare, and cultural diversity in modern Australia interact with environmental factors to influence brain ageing.
“The MAS2 cohort will allow us to investigate how different life experiences and environments shape ageing in the 21st century,” Professor Brodaty added.
With more than 200 scientific publications already arising from the study, this latest analysis strengthens the growing recognition that healthy ageing is determined not only by genes and lifestyle, but also by where you live.