Nearly half of dementia cases could be prevented by tackling modifiable risk factors such as physical inactivity, smoking, low education or social isolation, but new Curtin University research suggests current public health approaches are falling short of driving real behaviour change.

A major international review published in The Lancet Healthy Longevity has found while large-scale health awareness campaigns for dementia prevention can reach wide audiences, they often lead to only small improvements in knowledge and limited changes in behaviour.

The study analysed public health campaigns and programs across eight countries and found more engaging, personalised and community-driven approaches were needed to genuinely influence behaviour and reduce dementia risk.

Study author Professor Mario Siervo, from Curtin’s School of Population Health, said the findings showed a clear gap between what people know and what they do.

“Up to 45 per cent of dementia cases are linked to modifiable factors we can change, such as our lifestyle, health status and environment,” Professor Siervo said.

“But simply telling people what those risks are isn’t enough; awareness campaigns are important, but on their own they rarely lead to meaningful or lasting behaviour change.”

Professor Siervo also said a second new study conducted by the group has provided further evidence on the relevance of modifiable risk factors for dementia.

The results indicated that muscle strength and body composition play a significant role in dementia risk, highlighting the need for more targeted prevention approaches.

The Curtin-led research followed nearly 500,000 adults over more than a decade and found people with both low muscle strength and excess body fat — known as sarcopenic obesity — had a higher risk of developing dementia.

In contrast, obesity on its own was not associated with increased dementia risk if muscle strength was preserved, highlighting the importance of muscle health alongside maintaining an optimal body composition in dementia prevention.

Chair in Dementia at Curtin’s enAble Institute and co-author Professor Blossom Stephan said many people still did not realise dementia risk could be reduced.

“There is still a widespread belief that dementia is an unavoidable part of ageing, which is not the case,” Professor Stephan said.

“But even when people are aware of the risks, barriers such as time, cost and motivation can prevent them from making changes to their lifestyle.”

The review found interactive approaches were consistently more effective in motivating people to make lifestyle changes than passive information campaigns.

These included:

• Online education programs that guide people through practical steps to improve brain health
• Personalised risk assessments showing individuals how their lifestyle affects their dementia risk
• Community-based programs delivered by trusted local figures, such as peer educators, health workers or community leaders

Professor Siervo said these types of approaches were more likely to engage people and support sustained behaviour change.

“When people understand their own personal risk and are given clear, practical ways to act – especially through trusted community networks – they are more likely to make meaningful changes,” he said.

Examples of effective approaches included community education sessions run by local leaders, culturally tailored programs delivered in familiar settings and interactive courses helping participants set realistic health goals.

Professor Stephan said future public health strategies should move beyond awareness alone and focus on long-term engagement.

“We need to combine broad public messaging with targeted support that helps people take action,” she said.

“That means investing in programs that are accessible, culturally relevant and designed with communities, not just delivered to them.

“With dementia rates expected to rise significantly in coming decades, prevention is one of the most powerful tools we have -but to get there, we need to rethink how we communicate risk and support people to act on it.”

Population-level interventions for dementia prevention: a systematic review was published in The Lancet Healthy Longevity.