Brain health shaped by society, not just personal choices, dementia study warns

Dementia prevention strategies around the world may be asking too much of individuals while paying too little attention to the social and environmental conditions that quietly shape brain health across a lifetime, according to new research from Curtin University published in The Lancet Public Health. The study, titled ‘Beyond individual-level approaches to dementia prevention: a socioecological reappraisal’, argues that the dominant framing of dementia risk reduction — one built around personal motivation, lifestyle change and self-management — overlooks the fact that many of the strongest influences on dementia risk are never fully within a person’s control. The finding lands at a moment when the global burden of dementia is climbing steeply: an estimated 57 million people worldwide are living with the condition today, a figure projected to reach 139 million by 2050, with 78 million expected by 2030 alone.

To reach their conclusions, the researchers undertook a systematic mapping of 61 potentially modifiable dementia risk and protective factors, examining how each one is typically addressed in prevention research, policy and public health messaging. Their analysis revealed a striking imbalance. The overwhelming emphasis falls on factors that can, at least in theory, be addressed through individual motivation and behaviour change — exercising more, eating a better diet, staying socially active, managing blood pressure and other health metrics. By contrast, far less attention is devoted to the social and environmental determinants that sit upstream of those behaviours: the quality and availability of education, the safety and livability of neighbourhoods, housing conditions, access to healthcare, exposure to clean air, and opportunities for meaningful social connection. These are precisely the factors, the authors note, for which evidence of influence on lifelong brain health continues to accumulate.

Lead author Dr Jennifer Dunne, from Curtin University’s Dementia Centre of Excellence, said the findings challenge the way dementia prevention has traditionally been framed. Much of the current prevention effort, she explained, is focused on what individuals can do to reduce their risk — exercising more, eating well, staying socially connected and managing their health. Those behaviours remain important for a range of reasons, she acknowledged, but the study demonstrates that many of the factors shaping dementia risk do not sit solely within an individual’s control. Where people live, the education they receive, the healthcare they can access, the air they breathe and the social and economic conditions they experience across their lives can all shape brain health. If prevention focuses predominantly on individual behaviour, she warned, societies risk asking people to make healthier choices without addressing the conditions that make those choices possible in the first place.

The socioecological perspective at the heart of the paper is not a rejection of lifestyle advice but a reframing of where responsibility lies. A person’s ability to exercise regularly depends on safe streets, parks and free time. A nutritious diet depends on income, food availability and stable housing. Social connection depends on community infrastructure, work patterns and whether isolation is treated as a public health problem rather than a personal failing. Educational attainment, one of the most consistently documented protective factors against dementia in large international cohort studies, is determined decades before midlife risk factors come into play. By mapping the full set of 61 modifiable factors, the Curtin team was able to show how heavily the prevention literature leans toward the end of the causal chain that individuals can act on, while the upstream conditions that enable or obstruct those actions receive comparatively little systematic attention.

Co-author Professor Blossom Stephan, Chair in Dementia at Curtin’s enAble Institute, said the findings show that dementia prevention needs to take a broader, population-wide approach. The next step, she argued, is turning this evidence into action: dementia prevention should continue to support healthy choices while also improving education, neighbourhoods, healthcare access and the other social conditions that shape brain health across the population and throughout a person’s life. In practical terms, that means treating dementia risk reduction as a matter for education policy, urban planning, housing policy, environmental regulation and health system design, not only for clinical guidelines and individual counselling. The study’s method of research is described as computational simulation and modelling, reflecting the systematic way the team mapped and compared the distribution of attention across the different categories of modifiable factors.

The scale of the problem gives the argument urgency. In Australia, about 446,500 people are currently living with dementia, a number expected to exceed one million by 2065. Dementia is now the leading cause of death for Australians, overtaking other major causes as the population ages and as other leading killers have been progressively brought under control through decades of population-wide public health measures. That history is part of the researchers’ implicit point: conditions such as heart disease and several cancers saw major declines not because individuals suddenly willed themselves healthier, but because societies changed — through tobacco regulation, dietary guidelines, screening programs, road safety engineering and environmental standards. The paper suggests dementia prevention now stands at a similar juncture, where individual advice alone cannot deliver population-level change without matching structural action.

The international collaboration behind the study included Neuroscience Research Australia (NeuRA), UNSW Sydney and Dementia Australia, reflecting a coalition that spans laboratory science, clinical research and consumer advocacy. Dementia Australia Chief Executive Officer Professor Tanya Buchanan said that with 78 million people expected to be living with dementia worldwide by 2030, it is vital to make sure everyone is supported to lower their risk. Dementia risk reduction, she argued, is a collective responsibility, and it is vital that everyone has access to the supports and services they need to protect their brain health. Alongside addressing brain health behaviours at the individual level, she called for policies and actions from governments and organisations to make it easier for everyone to lower their risk — a formulation that places the burden of enabling healthy choices on institutions rather than on individuals alone.

The implications for public health policy are considerable. If education, housing quality, neighbourhood safety, healthcare access, air quality and social connection are genuine determinants of dementia risk, then investment in those domains becomes a form of dementia prevention, even when that is not the stated goal. A child’s schooling, an older adult’s walkable neighbourhood, a community’s access to primary care and a city’s air quality all become part of the brain health portfolio. Conversely, a prevention strategy that concentrates on individual behaviour change risks widening inequalities, because the people most exposed to adverse social and environmental conditions are often those with the fewest resources to act on health advice. The Curtin team’s reappraisal suggests that the well-documented socioeconomic gradients in dementia incidence may be, in part, a product of prevention frameworks that assume a level of individual control many people simply do not have.

The paper, ‘Beyond individual-level approaches to dementia prevention: a socioecological reappraisal’, was published in The Lancet Public Health on 9 September 2026, with no competing interests declared by the authors. Its central message is unlikely to be comfortable for prevention campaigns built around personal resolutions, but it arrives with a constructive agenda attached. Individual behaviours — exercise, diet, cognitive and social engagement, cardiovascular health management — remain genuinely protective and worth pursuing. What the study demands is a second, parallel track: population-wide action on education, housing, neighbourhoods, healthcare access, clean air and social connection, sustained across the life course. Brain health, the researchers conclude, is a collective achievement as much as a personal one, and the societies that treat it that way will be the ones best placed to bend the projected curve of dementia before 2050.

Subject of Research: Socioecological determinants of dementia prevention and modifiable risk factors

Article Title: Dementia prevention can’t rely on individual choices alone, new study finds

Article References: Dementia prevention can’t rely on individual choices alone, new study finds. (n.d.). Original publication

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Keywords: dementia, dementia prevention, public health, brain health, social determinants of health, Curtin University, The Lancet Public Health, modifiable risk factors, health policy, ageing, health inequality, population health