As public awareness of dementia grows, so too does the appetite for prevention. Global headlines tout the benefits of exercise, diet, brain training and social activity in reducing dementia risk.

In recent years, medical journals have amplified this message to encourage people to take control of their cognitive futures through lifestyle change. Last year, The Lancet estimated up to 45 percent of dementia cases worldwide could theoretically be delayed or prevented by addressing modifiable risk factors.

These messages are undeniably hopeful. They suggest personal effort, combined with emerging scientific evidence, can help to overcome a disease long seen as inevitable.

But public health messaging that focuses too narrowly on behavior may be misleading and potentially harmful, as we argue in The Lancet.

This can lead to a two-tiered system, where affluent people are praised for their proactive brain health, while marginalized groups face barriers to participation and are blamed for their perceived inaction.

What is dementia and what causes it?

Dementia is a neurocognitive disorder and describes conditions that affect memory, thinking and the ability to do everyday tasks. Alzheimer’s disease is the most common type, but there are others such as vascular and Lewy body dementia.

Dementia risk is related to socioeconomic disadvantage

Dementia risk is also determined by a complex array of extrinsic factors – conditions outside our control – that are unevenly distributed across society: air quality, ethnicity, gender, occupation, the built environment.

These factors influence not just if, but when, dementia might develop.

Dementia prevalence is disproportionately higher in communities facing social disadvantage partly because modifiable risk factors such as diabetes, obesity and low education are also more common in these areas.