The World Health Organization has added seven health conditions and exposures to its updated guidance on reducing the risk of cognitive decline and dementia, including stroke, head injuries, vision problems, sleep disorders, HIV, air pollution and menopausal hormone therapy.
The second edition of the WHO’s guidelines, published on July 15, 2026, expands on its original 2019 advice and sets out recommendations covering 19 potentially modifiable risk factors. The organisation said the guidance reflected new evidence and was intended to support action “across the life course”. ([who.int](https://www.who.int/news/item/15-07-2026-new-who-guidelines–up-to-45–of-dementia-risk-could-be-prevented-or-delayed))
More than 57 million people worldwide are living with dementia, according to the WHO, while almost 10 million new cases are diagnosed each year. The organisation estimates that up to 45% of dementia risk may be linked to factors that can potentially be changed or managed. ([who.int](https://www.who.int/news/item/15-07-2026-new-who-guidelines–up-to-45–of-dementia-risk-could-be-prevented-or-delayed))
Seven newly highlighted dementia risk factors
The newly highlighted areas are stroke, traumatic brain injury, vision impairment, sleep problems, HIV, air pollution and menopausal hormone therapy.
Stroke is already recognised as a major cause of long-term cognitive impairment, particularly when it occurs repeatedly. The updated guidance says the risk of dementia rises substantially after recurrent stroke, although it concludes that there is not enough evidence to recommend specific drug treatments solely for dementia prevention after a stroke. ([ncbi.nlm.nih.gov](https://www.ncbi.nlm.nih.gov/books/NBK623908/))
The WHO also stresses the importance of preventing head injuries. Traumatic brain injury can range from concussion to severe brain damage, but the organisation says there is currently insufficient evidence to recommend a particular treatment after such an injury specifically to reduce the risk of dementia. Preventive measures, including steps to reduce head injuries, should nevertheless be implemented consistently. ([ncbi.nlm.nih.gov](https://www.ncbi.nlm.nih.gov/books/NBK623908/))
Vision impairment has been linked with cognitive decline and dementia, potentially because of reduced sensory stimulation, social isolation and the extra mental effort involved in compensating for poor sight. The WHO says screening and treatment should be part of routine care, while acknowledging that there is not yet enough evidence to recommend eye treatment specifically as a dementia-prevention measure. ([ncbi.nlm.nih.gov](https://www.ncbi.nlm.nih.gov/books/NBK623908/))
Sleep problems, including insomnia, poor-quality sleep and sleep apnoea, have also been associated with a higher risk of cognitive decline. However, the WHO says the evidence is not yet strong enough to recommend sleep treatments specifically for the purpose of preventing dementia. ([ncbi.nlm.nih.gov](https://www.ncbi.nlm.nih.gov/books/NBK623908/))
For people living with HIV, the guidelines emphasise prompt antiretroviral treatment and maintaining an undetectable viral load. Effective treatment has greatly reduced severe HIV-related dementia, although milder cognitive impairment can still occur and there is insufficient evidence to recommend one particular antiretroviral combination over another for dementia prevention. ([ncbi.nlm.nih.gov](https://www.ncbi.nlm.nih.gov/books/NBK623908/))
Air pollution is another new focus. The WHO says reducing exposure to household and outdoor pollution, particularly fine particulate matter known as PM2.5, may reduce the risk of cognitive decline and dementia. It cautions, however, that the certainty of the evidence is low or very low because much of it comes from observational studies. ([ncbi.nlm.nih.gov](https://www.ncbi.nlm.nih.gov/books/NBK623908/))
The advice on menopausal hormone therapy is more cautious still. The WHO does not recommend using it specifically to prevent dementia in postmenopausal women aged 65 and over, while saying there is insufficient evidence to advise for or against its use for dementia prevention in younger women. ([ncbi.nlm.nih.gov](https://www.ncbi.nlm.nih.gov/books/NBK623908/))
Existing factors remain part of the guidance
The seven additions sit alongside factors already included in the WHO’s advice, such as physical inactivity, harmful alcohol use, smoking, unhealthy diet, obesity, diabetes, high blood pressure, abnormal blood fats, hearing loss, depression, and low levels of cognitive and social activity.
The updated guidance recommends measures including regular physical activity, stopping smoking, reducing harmful drinking, eating a healthy diet and managing conditions such as high blood pressure, diabetes and high cholesterol. It also says cognitive training and stimulating activities may be offered to older adults with normal cognition or mild cognitive impairment. ([who.int](https://www.who.int/news/item/15-07-2026-new-who-guidelines–up-to-45–of-dementia-risk-could-be-prevented-or-delayed))
The WHO does not recommend vitamin B or E supplements, omega-3 fatty acids or multivitamins to reduce dementia risk in people without a diagnosed deficiency, saying the evidence does not show that the potential benefits outweigh possible harms. ([who.int](https://www.who.int/news/item/15-07-2026-new-who-guidelines–up-to-45–of-dementia-risk-could-be-prevented-or-delayed))
Dr Daniel Amen, a US physician and founder of Amen Clinics in California, said the new guidance was broadly consistent with his approach to reducing Alzheimer’s risk. His “BRIGHT MINDS” framework covers blood flow, ageing, inflammation, genetics, head trauma, toxins, mental health, immunity and infections, neurohormones, obesity and type 2 diabetes, and sleep.
He said brain health should be considered throughout life rather than addressed only in later years, adding that social contact, learning and better lifestyle choices could all form part of a long-term prevention strategy.
The WHO says dementia costs the global economy an estimated 1.3 trillion US dollars each year, with about half of that burden arising from unpaid care provided by relatives and friends. It said earlier action on modifiable risk factors could help people remain independent for longer, while stressing that dementia does not have a single cause and cannot be prevented in every case. ([who.int](https://www.who.int/news/item/15-07-2026-new-who-guidelines–up-to-45–of-dementia-risk-could-be-prevented-or-delayed))
