Dementia is one of the biggest health challenges facing Australia’s ageing population. It affects individuals, families and communities – and places growing pressure on health and care systems.
But while dementia is often seen as an inevitable part of ageing, research tells a more nuanced story.
Over the past two decades, studies using data from the 45 and Up Study have helped shift our understanding of dementia – from something we can only respond to, to something we can better understand, and in some cases, help manage risk factors.
Looking beyond age: understanding risk
One of the most important contributions of the 45 and Up Study has been helping researchers understand who is most at risk of developing dementia – and why.
Large-scale analyses, including the ADAPTOR project – published in Sax Institute’s Public Health Research & Practice – have examined dementia incidence across the population, identifying how factors such as age, chronic disease, and social and economic characteristics interact to influence risk.
This research shows that dementia is a complex, multifactorial condition – not driven by age alone, but by a combination of influences that build over time. It has also helped identify opportunities for prevention and early intervention across the population.
From evidence to prevention
Insights from the 45 and Up Study have also enabled large-scale trials to test how dementia risk can be reduced in practice.
Led by Professor Henry Brodaty AO, the Maintain Your Brain trial which recruited more than 6,000 participants directly from the 45 and Up Study, tested how tailored, online programs targeting physical activity, nutrition, mental health and cognitive training could help reduce dementia risk.
Findings from the trial – published in Nature Medicine – showed that participants who received the personalised intervention had better cognitive outcomes over time compared to those who did not.
This demonstrates how large-scale, longitudinal studies like 45 and Up can do more than generate insight – they can support the development and testing of practical, scalable approaches to improving health outcomes.
Understanding the role of treatment
Research using 45 and Up data is also contributing to a growing understanding of how clinical care may influence dementia risk.
A long-term study published in GeroScience examined the relationship between commonly prescribed blood pressure medications and dementia outcomes. The study found that some treatments were associated with a lower risk of developing dementia over time.
These findings highlight how managing common health conditions may play a role in shaping dementia risk – and point to new opportunities for improving care and prevention strategies.
Planning for an ageing population
As Australia’s population ages, dementia is becoming an increasingly important component of health and aged care systems.
Research using 45 and Up data has provided important insights into how care is delivered, particularly during key transition points.
A study published in the Medical Journal of Australia found that people with dementia who changed general practitioners when entering residential aged care were more likely to be prescribed higher numbers of medications, including psychotropic medicines. This highlights the importance of continuity of care and better coordination when people move into residential care.
Further research published in the Journal of the American Medical Directors Association found that access to appropriate home care can influence how long people with dementia are able to remain living at home before requiring residential care.
Together, these findings show that dementia is not only a health issue – but a system-wide challenge, where the timing, coordination and quality of care can significantly shape outcomes.
Why large-scale, longitudinal research matters
Dementia develops over many years, often influenced by a combination of biological, environmental and social factors.
Understanding these patterns requires long-term, large-scale data – something only studies like 45 and Up can provide.
By linking survey data with health records and following participants over time, the study has enabled researchers to generate insights that would not be possible through smaller or shorter-term studies.
This has resulted in a substantial body of published research – across Australian and international journals – that continues to inform policy, practice and future research.
A legacy that continues
The insights generated through the 45 and Up Study are already shaping how we understand and respond to dementia in Australia.
But this work is far from finished.
As we look to the future, national initiatives like 18 and Up will build on this legacy – extending our understanding of health and wellbeing across generations.
And at the heart of it all are the participants who have made this research possible.
Their ongoing contribution is helping to create a future where conditions like dementia are better understood – and better prevented. We are proud to share their impact to health and wellbeing as part of our ongoing celebration of 20 years of the 45 and Up Study.
