Nearly Half of Dementia Cases May Be Preventable: What the New WHO Guidelines Means

‍In July 2026, The World Health Organization (WHO) has released the second edition of its Guidelines on Risk Reduction of Cognitive Decline and Dementia, delivering one of the most encouraging messages in dementia prevention to date: this is that up to 45% of dementia cases may be delayed or prevented by addressing modifiable risk factors throughout life.

For Australian general practice, this reinforces something GPs already do every day—support healthy lifestyles, manage chronic disease and promote preventive care. While there is still no cure for dementia, these updated guidelines highlight the significant opportunity to reduce risk long before symptoms appear. ‍

Dementia prevention starts early

More than 57 million people worldwide are currently living with dementia, with numbers expected to continue rising as populations age. The personal, social and economic burden is substantial, making prevention more important than ever.

The WHO emphasises that the risk of dementia risk increases with age. However, rather than being determined by age alone, risk of dementia is influenced by factors beginning in childhood and continuing through adulthood.

The updated guidelines group risk factors into three broad categories:

• Lifestyle and behavioural factors

• Health conditions and biological factors

• Environmental factors

Many of these are already familiar targets of preventive healthcare in general practice.

Lifestyle matters more than ever

The strongest evidence continues to support healthy lifestyle habits as the foundation of dementia risk reduction.

Keep the brain active

Lifelong learning appears to play an important role in maintaining cognitive health. This begins with quality education in childhood but continues throughout adult life through intellectually stimulating work, hobbies and social engagement.

For older adults, cognitive activities such as reading, storytelling, puzzles, card games and structured cognitive training may help maintain cognitive function, particularly in people with mild cognitive impairment.

Stay socially connected

Social isolation and loneliness are now recognised as important modifiable risk factors.‍ ‍

Encouraging people to maintain friendships, participate in community groups, volunteer or remain engaged with family can contribute to healthier cognitive ageing. For older adults, even small increases in regular social interaction may be beneficial.

Move more

Regular physical activity remains one of the strongest evidence-based interventions for reducing dementia risk.

The WHO recommends maintaining physical activity throughout life, with evidence suggesting it may also help delay progression in people with mild cognitive impairment.

Avoid smoking and limit alcohol

The updated guidelines reinforce the benefits of smoking cessation for reducing dementia risk.‍ ‍

Similarly, avoiding harmful alcohol consumption remains an important recommendation, adding to the long list of health benefits already associated with reducing alcohol intake.

Prioritise healthy eating

‍A nutritious, balanced diet is recommended across the lifespan. Rather than focusing on supplements, the WHO concludes there is insufficient evidence that vitamin B, vitamin E, omega-3 fatty acids or multivitamin supplementation reduces dementia risk.‍ ‍

The emphasis remains on healthy dietary patterns rather than individual supplements.

Managing chronic disease protects brain health‍ ‍

Many of the risk factors for cardiovascular disease are also risk factors for dementia.

Obesity, diabetes, hypertension and high cholesterol‍ ‍

Preventing obesity, particularly during midlife, can reduce dementia risk.

Similarly, preventing or effectively managing hypertension, diabetes and hypercholesterolaemia is associated with reduced cognitive decline. For patients already diagnosed with these conditions, good control remains an important part of dementia prevention.

This highlights another valuable opportunity for general practice—optimising cardiovascular health may also be protecting long-term brain health.

Stroke prevention‍ ‍

Stroke remains a major contributor to cognitive impairment.

While there are no specific post-stroke treatments proven to prevent dementia, preventing stroke in the first place remains critical. Effective management of high blood pressure (hypertension), diabetes, atrial fibrillation, smoking and other vascular risk factors continues to be one of the most powerful preventive strategies.

Preventing head injury‍ ‍

Traumatic brain injury is another recognised risk factor.

Simple preventive measures including helmet use where applicable, workplace safety and adherence to concussion guidelines in community and professional sport remain important strategies during life.

Other health conditions also matter

The WHO also reviewed a range of other medical conditions associated with dementia risk.‍ ‍

Treating hearing loss may help slow cognitive decline in people with mild cognitive impairment, supporting routine hearing assessment and early intervention where appropriate.

Vision correction has less direct evidence for reducing dementia risk, although maintaining vision remains important for preserving independence and reducing social isolation.

For people living with HIV, maintaining viral suppression is recommended, although current evidence does not support one antiretroviral regimen over another for dementia prevention.

The guidelines also reviewed menopause, depression and sleep. Although women experience dementia more frequently than men, menopausal hormone therapy should not be prescribed solely to reduce dementia risk. The role of hormone therapy remains primarily in the management of menopausal symptoms.

Similarly, while depression and poor sleep should always be appropriately assessed and managed, current evidence does not support antidepressants or sleep interventions specifically for dementia prevention.

A new focus on environmental health‍ ‍

One of the notable additions in the updated WHO guidelines is the recognition of environmental risk factors.

Reducing exposure to household air pollution such as using cleaner cooking fuels including electricity or natural gas may reduce dementia risk.

The WHO also recommends reducing exposure to outdoor air pollution wherever possible, recognising that environmental factors contribute to lifelong brain health alongside individual lifestyle choices.

What does this mean for Australian general practice?

Perhaps the most reassuring aspect of the updated WHO guidance is that dementia prevention aligns closely with good primary care.‍ ‍

Supporting patients to stop smoking, remain physically active, eat well, stay socially connected, manage chronic disease, protect their hearing and reduce cardiovascular risk may all contribute to healthier cognitive ageing.

Importantly, these conversations should not begin at retirement. Dementia prevention is a lifelong process, with the greatest benefits likely achieved when healthy habits are established early and maintained across adulthood.

Key takeaways

The WHO's updated 2026 guidelines reinforce an important message: while dementia cannot yet be cured, many of its risk factors are modifiable.

Up to 45% of dementia cases may be delayed or prevented through healthy lifestyle choices, effective chronic disease management and reducing environmental risk factors.

For GPs, this represents another opportunity to frame preventive healthcare not only as protecting the heart and metabolic health, but also as protecting the brain. Every discussion about exercise, smoking cessation, blood pressure, diabetes management or social connection may also be a conversation about reducing a patient's future risk of dementia.

Reference

1. Risk Reduction of Cognitive Delcine and Dementia, WHO Guidelines, 2nd Edition; https://iris.who.int/server/api/core/bitstreams/ea44b7f6-b09f-4e6f-b8c7-2e5b0fcc9a99/content. [22/07/26].

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