For a long time, dementia was largely viewed as an unavoidable consequence of ageing. That picture is changing.

In July, the World Health Organization (WHO) released updated guidelines on dementia risk reduction, estimating that up to 45% of dementia risk can be attributed to potentially modifiable factors. These include physical inactivity, smoking, harmful alcohol use, social isolation, air pollution and conditions such as hypertension and diabetes.

This does not mean that dementia can always be prevented. Age, genetics and other factors remain important. But it does mean there is considerably more scope for prevention and risk reduction than was once assumed.

Knowing isn't the same as doing

A new report from the Centre for Aging + Brain Health Innovation (CABHI), developed with Alzheimer's Society, Toronto Metropolitan University's National Institute on Ageing and the Toronto Dementia Research Alliance, suggests that awareness is only part of the problem. The real challenge may be turning it into action.

The report surveyed 2,090 adults aged 40 and over in the UK and Canada about dementia prevention, brain-healthy behaviours and the role technology could play.

The findings reveal that around two-thirds of respondents believed that dementia risk can be reduced, while 72% recognised that actions taken during midlife or earlier can have the greatest impact. Yet only 43% felt informed about how to reduce their own risk, and just 17% felt more than moderately confident in their ability to do so.

People were also much more likely to recognise familiar health behaviours. Many understood the importance of physical activity and social engagement, while awareness was considerably lower for factors such as depression, hearing and vision loss and air pollution.

For physical activity and social engagement, respondents commonly cited lack of motivation, lack of time and difficulty changing routines as barriers.

Where digital health could help

Technology is already deeply embedded in everyday life: 95% of those surveyed reported using digital technology. The report points to an opportunity to build brain-health support into technologies and habits that already exist.

Wearables can provide feedback on movement and activity. Apps can help people monitor sleep, medication or cardiovascular risk factors. Digital platforms can facilitate social connection, while reminders, progress tracking and personalised feedback may make healthy behaviours easier to maintain.

There is already good reason to focus on these behaviours beyond dementia. WHO identifies physical activity, social and cognitive engagement, healthy diet, smoking cessation and the management of blood pressure, cholesterol and blood sugar among the actions that can support lower dementia risk.

A smartwatch encouraging someone to move more, a digital programme supporting hypertension management or a platform helping someone remain socially connected may all support brain health without dementia prevention being their primary purpose.

That could also make these interventions easier to adopt. CABHI found that people were already making many brain-healthy choices for other reasons: 63% reported exercising to improve their general health, 48% had improved their diet and 44% were managing chronic health conditions. Maintaining quality of life and independence were stronger motivations than dementia prevention alone.

Instead of asking people to add another health goal to an already crowded list, digital health products could make the cognitive benefits of existing healthy behaviours more visible.

Brain health is also mental health

The findings also challenge the tendency to separate mental, physical and cognitive health into neat categories.

Depression is among the health conditions associated with increased dementia risk, while social isolation and physical inactivity also matter for both mental and cognitive health. WHO's latest guidance takes a similarly broad approach, combining lifestyle, cardiovascular, social and environmental factors across the life course.

For digital mental health, this creates an opportunity to think beyond symptom management. Tools designed to support mental wellbeing, social connection, sleep or healthy routines may form part of a much longer-term approach to brain health.

But this also requires care. An association between a risk factor and dementia does not mean that treating that factor will necessarily prevent dementia in an individual. Digital tools should support evidence-based healthy behaviour, not promise outcomes that science cannot guarantee.

There is also a risk of treating technology as the answer to problems that are fundamentally structural.

The trust problem

AI introduces another challenge: trust. Although 26% of respondents said they already use AI systems in daily life, CABHI identified trust as a significant barrier to using AI for health and medical purposes. The report argues that transparency, privacy, clinical validation and human oversight will be essential if AI-enabled health tools are going to gain credibility.

What comes next

The science around dementia risk is giving people more agency over their long-term brain health. But information by itself has limits.

The CABHI findings suggest that the next challenge is less about telling people that exercise, social connection or cardiovascular health matter and more about helping them turn those recommendations into behaviours they can sustain.

Technology could be part of that transition, particularly when it works with tools people already use and motivations they already have. But the most effective solutions will need to recognise that behaviour is shaped by far more than knowledge: time, motivation, money, healthcare access and trust all matter.

The future of dementia prevention may therefore depend not on another app telling us what is healthy, but on designing technology, and health systems, that make healthier choices easier to maintain.

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