The World Health Organization says up to 45% of dementia risk could be prevented or delayed by addressing modifiable risks across life. For adults in midlife, its 2026 advice favors blood pressure, cholesterol, hearing, activity and social connection over supplements and single superfoods.
Modifiable risk means factors people and health systems can change. Dementia means a lasting loss of memory, thinking and daily function. More than 57 million people live with dementia worldwide, with nearly 10 million new cases each year.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- What the 45% number really means
- The 14 factors behind the estimate
- What WHO advises in midlife
- Hearing, vision and supplements
- How to act without overpromising
What the 45% number really means
The 45% figure comes from the 2024 Lancet Commission review. That review found 14 modifiable factors together account for about 45% of dementia cases at population level, up from 40% and 12 factors in 2020, according to ScienceAlert reporting on the Lancet Commission. It is a population attributable fraction. It estimates the share of cases linked to those risks across a population.
It is not a personal guarantee. Age, genetics and disease processes still matter. No cure exists. A healthy adult in midlife can still develop dementia.
The 14 factors behind the estimate
The listed factors are less education, hearing loss, high LDL cholesterol, depression, brain injury, physical inactivity, diabetes, smoking, hypertension, obesity, heavy alcohol use, social isolation, air pollution and untreated vision loss. They span childhood, midlife and late life. Two additions changed the 2024 total.
High LDL cholesterol from around age 40 and untreated late-life vision loss were newly added. High LDL was estimated to contribute about 7% of cases. That finding cuts against common online claims that cholesterol only affects heart disease. For brain health, midlife cholesterol care counts.
What WHO advises in midlife
The World Health Organization released second-edition guidelines for reducing cognitive decline and dementia on 15 July 2026 in the World Health Organization announcement. For midlife adults, the advice centers on daily habits and vascular control.
The guidance covers physical activity, quitting tobacco, limiting alcohol, healthy diet and lower air-pollution exposure. It also covers controlling blood pressure, diabetes and cholesterol, plus social engagement and cognitive activity, as summarized in the PAHO summary of the WHO guidance. Practical midlife checks include:.
- Ask about blood pressure, blood sugar and LDL cholesterol, then follow the treatment plan
- Move most days, avoid tobacco, keep alcohol low and eat a balanced diet
- Stay socially active and keep the mind engaged through work, learning or hobbies
- Protect hearing and vision and seek care promptly for loss
Hearing, vision and supplements
WHO advises offering hearing aids to adults with hearing loss as part of risk reduction. That advice counters common online posts that ignore hearing and vision care for brain health. Untreated hearing loss can reduce conversation and social contact.
Untreated vision loss can reduce activity, independence and mental stimulation. Both deserve prompt testing and treatment. WHO does not recommend vitamin B, vitamin E, omega-3 PUFA or multivitamin and mineral supplements to reduce dementia risk without diagnosed deficiency. The reason is insufficient evidence of benefit outweighing harm.
How to act without overpromising
Dementia is the seventh leading cause of death. Alzheimer's causes 60-70% of cases. Prevention therefore matters for older adults, families and health systems, not only for one person. Midlife is a useful window because blood vessels, hearing, mood, activity and habits shape later brain health.
Small steady steps are easier to keep than a short overhaul. A primary-care visit can set priorities for the next year. Book hearing and eye checks if conversation is harder or reading needs brighter light. Bring a list of blood pressure, cholesterol, diabetes, smoking, alcohol, mood, sleep, activity and social contact to the visit.
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