The World Health Organization has published an updated edition of its guidelines on reducing the risk of cognitive decline and dementia.
The second edition expands the 2019 guidance and takes a broader life-course approach, covering healthy behaviours, management of medical conditions, environmental exposures and tailored combinations of interventions.
Why prevention matters
Dementia is not a single disease. It is a clinical syndrome caused by several brain disorders, including Alzheimer disease, and affects memory, reasoning and the ability to function independently.
There is no widely available curative treatment. That makes risk reduction an important public-health strategy even though no intervention can guarantee that an individual will avoid dementia.
WHO says more than 57 million people are living with dementia globally and nearly 10 million new diagnoses occur each year.
What has changed in the new guidance
The revised guideline incorporates a much larger evidence base than was available in 2019.
It keeps established areas such as physical activity, tobacco and alcohol use and management of cardiometabolic conditions, while adding recommendations related to environmental risk factors and multidomain interventions tailored to an individual's risk profile.
The guidance is aimed at adults without dementia, including people with normal cognition and those with mild cognitive impairment.
Modifiable risk does not mean preventable in every individual
WHO notes that a substantial share of dementia risk is associated with modifiable factors, including high blood pressure, diabetes, physical inactivity, smoking, harmful alcohol use, social isolation and air pollution.
That is a population-level statement. It does not mean dementia can always be prevented by changing behaviour, nor does it imply that people who develop dementia failed to protect themselves.
Genetics, ageing biology and factors that cannot be modified also contribute.
Why a life-course approach makes sense
Brain health in later life is influenced by exposures accumulated over decades.
Blood-pressure control, diabetes management, smoking avoidance, physical activity, hearing care, social engagement and reduced exposure to air pollution act through different mechanisms. Their effects therefore cannot be reduced to a single 'anti-dementia' intervention.
The updated WHO approach treats dementia prevention as part of broader cardiovascular, metabolic, environmental and social health rather than as a late-life intervention alone.
What the guidance does not support
The guidelines do not establish that any supplement, app, cognitive game or single lifestyle intervention can prevent dementia.
Where evidence is weak or incomplete, WHO identifies research gaps rather than converting biological plausibility into a recommendation.
That distinction is important because dementia prevention is an area where commercial claims often run ahead of clinical evidence.
Primary sources
- World Health Organization. Risk reduction of cognitive decline and dementia: WHO guidelines, second edition. 15 July 2026. https://www.who.int/publications/i/item/9789240123557
- World Health Organization. Executive summary, second edition. 2 September 2026. https://www.who.int/publications/i/item/B09867