WHO updates guidelines on dementia and indicates new measures to reduce the risk of the disease

In the text, the WHO emphasizes that there is still no widely accessible treatment capable of modifying the progression of the disease or curing it. Therefore, lifelong prevention remains the most effective strategy to reduce the number of new cases.

According to the entity, 57 million people live with dementia worldwide, and up to 45% of cases are associated with modifiable risk factors, such as lifestyle habits and health conditions that can be prevented or treated.

The percentage, however, does not mean that each person can individually reduce the risk of the disease by that proportion. This is a population estimate of the joint contribution of these factors.

"In Brazil, this proportion is even higher: it reaches 59%, almost 60%. The number is an indicator of the size of the space we have to act on prevention", says Cleusa Ferri, researcher at the Federal University of São Paulo (Unifesp) and member of the group that participated in the development of the new guidelines.

What was included

The evidence review allowed us to expand the scope of recommendations and incorporate themes that have gained scientific relevance in recent years. The guidelines now include new conditions associated with the risk of dementia and reinforce existing guidelines.

The 2019 guidelines already considered the relationship between dementia and conditions such as:

• obesity;

• diabetes;

• hypertension;

• high cholesterol, or dyslipidemia;

• hearing loss;

• depression;

• changes related to sleep.

In the 2026 update, the following became part of the document:

• HIV infection;

• cerebrovascular accident (CVA);

• head trauma;

• air pollution;

• visual impairment.

Air pollution appears for the first time among the recommendations. The WHO advises reducing exposure to both environmental pollution, especially fine particles, known as PM2.5, and pollution inside homes, as a strategy to reduce the risk of cognitive decline and dementia. The evidence, however, is still considered limited.

What is still valid

Among the main recommendations that remain valid to reduce the risk of dementia are:

• practice physical activity regularly;

• maintain a healthy and balanced diet;

• give up smoking;

• reduce or stop alcohol consumption;

• control body weight;

• treat diabetes, hypertension and high cholesterol;

• correct hearing loss;

• keep the brain active with cognitive activities, such as reading, games and storytelling;

• preserve coexistence and social participation.

What is not supported by evidence

The guidelines reinforce that supplements of vitamins B and E, omega-3 and multivitamins should not be used to prevent dementia in people without nutritional deficiencies.

Hormone replacement therapy is also not indicated for this purpose in women aged 65 or over. For younger women, the WHO states that the evidence is still insufficient to guide use for this purpose.

Next steps

For Cleusa, the next step is to incorporate dementia into chronic disease prevention actions.

"Brazil already promotes physical activity, combats smoking, encourages the reduction of alcohol consumption and control of hypertension and diabetes. We need to include dementia in this strategy and evaluate, based on the reality of the SUS, which measures can be incorporated", he states.

Another point is the need for new research in different populations. Despite advances in studies, the WHO emphasizes that there are still important gaps in scientific knowledge and that much of the evidence comes from observational research carried out in high-income countries.

In this sense, studies such as the one published this week by Pulsa gain importance. Developed with elderly people in Latin America, the research showed that it is possible to adapt protocols designed to improve the cognition of people at greater risk of dementia to regional characteristics.

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