The World Health Organization released updated global guidelines on dementia prevention on 15 July 2026, concluding that up to 45% of dementia risk is linked to factors within our collective power to change. The second edition of its guidelines on reducing cognitive decline and dementia is the first substantive update since 2019 and arrives as the global toll of the disease continues to rise.
More than 57 million people worldwide are living with dementia, and nearly 10 million new cases are diagnosed every year, according to the WHO. Alzheimer's disease, the most common form, accounts for an estimated 60 to 70% of those cases. With no cure available, the WHO says prevention and risk reduction across a person's entire life remain the most effective tools health systems have.
What the risk factors are — and what is new
The guidelines identify modifiable risk factors — behaviours and exposures that can realistically be changed — including tobacco use, harmful alcohol consumption, physical inactivity, social isolation, high blood pressure and diabetes. The economic cost of dementia reinforces the urgency: the condition costs the global economy an estimated $1.3 trillion each year, with roughly half of that burden falling on unpaid family carers.
The 2026 update expands significantly on its predecessor. Eight new areas have been incorporated into the framework: sleep, air pollution, traumatic brain injury, vision impairment, HIV, stroke, menopause and multidomain interventions — meaning programmes that address several risk factors at once rather than one in isolation. Air pollution's formal inclusion is among the most consequential additions. Where previous prevention guidance focused primarily on lifestyle and cardiovascular health, WHO now classifies exposure to polluted air as a recognised dementia risk, with practical implications for urban planning and public health policy worldwide.
“"We know more today than ever before about what drives dementia risk, and these guidelines translate that knowledge into action," said Dr. Tedros Adhanom Ghebreyesus, WHO Director-General.”
What individuals and governments can do
The guidelines recommend a combination of behavioural and clinical actions. For individuals with normal cognition or mild cognitive impairment — a condition where memory or thinking difficulties are present but do not yet significantly affect daily life — the WHO recommends cognitive training, mental stimulation and regular social engagement. Research cited in the guidelines estimates that roughly one in four older adults experiences social isolation, and that eliminating loneliness alone could potentially prevent around 5% of dementia cases. Managing conditions such as hypertension, diabetes and high cholesterol is also recommended, as is the use of hearing aids for those with hearing loss.
The guidelines advise against routinely taking vitamin B, vitamin E, omega-3 or multivitamin supplements to reduce dementia risk unless a specific deficiency has been identified. The WHO also recommends against the use of menopausal hormone therapy as a strategy to reduce dementia risk, citing insufficient evidence for this application. For several other newly evaluated factors, including sleep disorders, traumatic brain injury and HIV management, the evidence was assessed as currently insufficient to support formal recommendations — though all were flagged for continued research.
“"Guidelines of this scope reflect a field that has matured — and a body of evidence that has earned them," said Sheena Aurora, M.D., Alzheimer's Association vice president of medical affairs.”
A call for systemic change, not just individual action
The WHO is directing its guidance as much at governments and health systems as at individuals. The updated guidelines argue that dementia risk reduction should be built into existing programmes for noncommunicable diseases, mental health and urban environmental policy — rather than treated as a standalone concern. Many of the risk factors for dementia, including hypertension, obesity and diabetes, are already targets of public health campaigns worldwide. The WHO argues that integrating brain health into those existing frameworks would be both cost-effective and scalable, particularly in low- and middle-income countries, where dementia caseloads are growing fastest.
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