Risk factors for developing dementia have been identified. They can be classified as non-modifiable and modifiable, and can operate both at an individual level and within the context of the community and society.
Non-modifiable risk factors
These are characteristics that cannot be changed, such as age, genetic factors and female sex. These factors help identify people at greater risk.
Age
Ageing, particularly brain ageing, is the main risk factor for developing dementia. Average life expectancy, which has increased by around 15 years compared with 1960, is an important factor in the growth in the number of cases.
The prevalence of dementia doubles every five years from the age of 60, and it is estimated that around 30% of people aged 85 have some form of dementia.
Genetic factors
There are genetic factors that may increase the risk of dementia. These are particularly relevant in early-onset forms of Alzheimer's disease, when the disease develops before the age of 65. The genetic component also plays an important role in people with trisomy 21.
Female sex
Dementia is more common in women, which may be associated with greater longevity, historical differences in education and career paths, hormonal factors and a higher frequency of stress and depression throughout adult life.
Modifiable risk factors
Recent studies suggest that addressing certain factors by adopting a healthy lifestyle and preventive measures may reduce or delay the development of dementia. These factors include aspects related to lifestyle, physical and mental health and the psychosocial context.
In developed countries, a trend towards dementia beginning at a later age has been observed. This may be linked to better control of cardiovascular risk factors, reduced smoking, higher levels of education and an overall improvement in lifestyles.
The Lancet Commission on Dementia Prevention, Intervention and Care identified 14 potentially modifiable risk factors across the life course, distinguishing between risk factors present in early life, midlife and later life. It is estimated that up to 45% of dementia cases could be prevented or delayed by addressing these factors.
1. Low level of education
Education contributes to the development of cognitive reserve, understood as the brain's capacity to compensate for damage or changes associated with ageing. For this reason, a low level of education is associated with a greater risk of developing dementia.
Policies that promote universal access to education are an important strategy for reducing the risk of dementia in the long term. In addition, keeping the brain active through cognitively stimulating activities throughout life may help maintain cognitive function.
2. Hearing loss
It is important to reduce exposure to excessive noise, whether at work or in other environments. When hearing loss is already present, the use of hearing aids has been associated with benefits in protecting cognition.
3. Depression
There is an increased risk of dementia among people who develop depression at any age. When depression occurs in later life, it may, in some cases, be an early manifestation of a neurodegenerative disease. It is important to treat depression effectively through psychotherapy, pharmacotherapy or a combination of both.
4. Head trauma
To prevent traumatic brain injuries, appropriate protective equipment is essential in work that requires safety measures and in mobility and leisure activities, for example on construction sites, when using bicycles and scooters and when taking part in contact sports.
5. Smoking
Studies have suggested an association between stopping smoking and a reduction in risk.
6. Physical inactivity
Physical activity is associated with better brain function, partly because it improves cerebral blood flow. During physical exercise, substances are released that help protect the brain and support its function.
7. High blood pressure
Controlling high blood pressure from midlife onwards has been associated with a reduction in risk.
8. Cholesterol
High LDL cholesterol in midlife may be a risk factor.
9. Obesity
Weight loss, even if modest, has been associated with a reduction in risk, particularly when linked to adopting healthy habits such as dietary changes and physical exercise.
10. Diabetes
Adequate diabetes control has been associated with a reduction in the risk of developing dementia.
11. Excessive alcohol consumption
Excessive alcohol consumption has been associated with a reduction in the volume of grey matter in the brain. Reducing excessive consumption helps preserve brain health.
12. Vision loss
Appropriate treatment of cataracts and other eye problems may help reduce risk.
13. Social isolation
Social contact is linked to increased cognitive reserve, the promotion of healthy behaviours and reduced stress and inflammation.
14. Air pollution
The impact of prolonged exposure to airborne particles, both outdoors and in the home, for example from residential wood burning, has been increasingly studied.
According to the Commission, other factors that may be associated with the risk of dementia but for which there is not yet consistent scientific evidence are related to sleep, diet, infections and systemic inflammation, dental disease, bipolar disorder, psychotic disorders, anxiety disorders and menopause-related factors.
These findings reinforce the importance of changing individual habits and implementing public policies aimed at promoting brain health and reducing risk factors in the population.
Bibliographic references
Mainly referring to the pages Dementia I Risk factors I Prevention I
Alzheimer’s Research & Prevention Foundation (2026, July 13). 4 Pillars of Prevention. Retrieved July, 13, 2026 from https://alzheimersprevention.org/4-pillars-of prevention/
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World Health Organization. (2026). Risk reduction of cognitive decline and dementia: WHO guidelines (2nd ed.), Retreived July 16, 2026 from https://www.who.int/publications/i/item/9789240123557