WHO adds air pollution to dementia risk factors, says up to 45% of cases may be prevented

The World Health Organization (WHO) has issued updated global guidelines stating that up to 45% of dementia cases could be prevented or delayed by addressing modifiable risk factors such as high blood pressure, diabetes, smoking, physical inactivity and, for the first time, air pollution. The agency has also advised against the routine use of vitamin and omega-3 supplements for dementia prevention in people without a diagnosed deficiency.

The revised recommendations, the first major update since 2019, are based on growing scientific evidence showing that lifestyle choices, effective management of chronic diseases and environmental exposures play a significant role in maintaining brain health.

Air pollution added as a key dementia risk factor

WHO has included air pollution in its dementia prevention guidance for the first time, citing increasing evidence linking long-term exposure to polluted air with cognitive decline. The update reflects a broader understanding of environmental factors that may contribute to dementia risk.


The recommendation is supported by the 2024 Lancet Commission on Dementia Prevention, Intervention and Care, which identified air pollution as one of 14 modifiable risk factors that together could account for up to 45% of dementia cases. A 2024 study published in BMJ Public Health also identified both outdoor and indoor air pollution as important dementia risk factors among the Indian population.

Healthy lifestyle and disease management recommended

WHO recommends regular physical activity, quitting tobacco, limiting alcohol intake, following a healthy diet, staying socially engaged and mentally active, and effectively managing high blood pressure, diabetes and high cholesterol. The use of hearing aids, where clinically indicated, may also help lower the risk of dementia.

"We know more today than ever before about what drives dementia risk, and these guidelines translate that knowledge into action," WHO Director-General Dr Tedros Adhanom Ghebreyesus said.

"Countries now have clear, evidence-based recommendations they can put into practice immediately to protect people's cognitive health," he added.

WHO advises against routine supplements

The organisation has advised against the routine use of vitamins B or E, omega-3 fatty acids, or multivitamin-mineral supplements to prevent dementia in people without a diagnosed deficiency, saying current evidence does not demonstrate sufficient benefit.

Dementia burden expected to rise in India

WHO said the updated guidance is especially relevant for countries such as India, where dementia cases are expected to increase with an ageing population. A nationally representative study published in the peer-reviewed journal Alzheimer's & Dementia estimated that around 8.8 million Indians aged 60 years and above are living with dementia, based on a prevalence of 7.4% among older adults.

Dementia is a progressive brain disorder that affects memory, thinking and the ability to carry out daily activities. Alzheimer's disease accounts for an estimated 60% to 70% of all dementia cases. Although there is no cure, WHO says a significant share of cases can be prevented or delayed through healthier lifestyles and better management of chronic health conditions.

Global health and economic impact

More than 57 million people worldwide are living with dementia, and nearly 10 million new cases are diagnosed each year.

WHO estimates that dementia costs the global economy about $1.3 trillion annually. Around half of that economic burden comes from unpaid care provided by family members and friends.

(With inputs from TOI)