Can dementia be prevented?

There is no guaranteed method. Addressing the 14 risk factors may delay onset or reduce risk.

Where should I start?

Get a health check that covers blood pressure, cholesterol and blood sugar, and have your hearing and vision tested. Physical activity and social connection also matter.

The evidence for dementia prevention is limited and the WHO recommendation is conditional. They do not replace exercise or managing health conditions.

What science says about dementia prevention — 14 risk factors and the latest trials

This article is general information, not medical advice, diagnosis or treatment. If you are worried about symptoms, please talk to a doctor or a local support service.

Short answer: There is no guaranteed way to prevent dementia. But an international expert commission estimates that addressing 14 modifiable risk factors — including hearing loss, high blood pressure, high cholesterol, inactivity, smoking and social isolation — could in theory prevent or delay up to about 45% of cases. "Prevention" here means delaying onset or slowing progression, not making dementia impossible.

The scale of the problem

According to the World Health Organization, about 57 million people were living with dementia worldwide in 2021, with nearly 10 million new cases each year. Alzheimer's disease accounts for 60–70% of cases. In Japan, a government-funded study published in 2024 estimated 4.43 million people aged 65+ with dementia in 2022, rising to about 5.84 million by 2040 — lower than earlier projections, which the researchers linked partly to falling smoking rates and better management of conditions such as high blood pressure and diabetes.

The 14 risk factors (Lancet Commission, 2024)

The 2024 report of the Lancet Commission listed 14 modifiable risk factors, adding high LDL cholesterol in midlife and untreated vision loss in later life to the 12 from 2020.

Early life

Less education

Midlife (roughly 18–65)

Hearing loss
High LDL cholesterol
Depression
Traumatic brain injury
Physical inactivity
Diabetes
Smoking
Hypertension
Obesity
Excessive alcohol

Later life (65+)

Social isolation
Air pollution
Untreated vision loss

Eliminating all 14 could, in theory, prevent or delay about 45% of dementia worldwide. The largest contributions were midlife hearing loss and high LDL cholesterol, about 7% each.

The 45% figure is a population attributable fraction, calculated by assuming each association is causal. It is not how much an individual can reduce their own risk, and it varies by country.

What intervention trials found

Most risk factors come from observational studies. Whether changing them actually reduces dementia must be tested in trials, and the results so far show both promise and limits.

FINGER (Finland, 2015)

People aged 60–77 at elevated risk received two years of dietary guidance, exercise, cognitive training and vascular risk management. The intervention group scored slightly but significantly better on cognitive tests than controls. The difference was small, but the trial launched similar multidomain studies worldwide (WW-FINGERS).

J-MINT (Japan, 2024)

531 people aged 65–85 with mild cognitive impairment received 18 months of risk-factor management, exercise classes, nutrition counselling and tablet-based cognitive training. The primary cognitive outcome did not differ significantly from the control group. Participants who attended at least 70% of exercise classes showed improvement, and some higher-risk subgroups appeared to benefit.

SPRINT MIND (USA, 2019)

About 9,300 adults with high blood pressure were treated to a systolic target below 120 mmHg or below 140 mmHg. The intensive group had a 19% lower risk of mild cognitive impairment. A clear effect on dementia itself was not shown, partly because the trial ended early.

ACHIEVE (USA, 2023)

977 adults aged 70–84 with hearing loss received hearing aids and audiology support for three years. There was no difference in cognitive decline overall. In a subgroup at higher risk to begin with, decline was 48% slower.

WHO guidelines

The WHO's 2019 guidelines reviewed physical activity, stopping smoking, diet, alcohol, cognitive training, social activity, weight, blood pressure, cholesterol, blood sugar and hearing. For cognitive training, the recommendation was conditional and the evidence very low to low (see Does brain training work?).

What this suggests for daily life

These steps matter for your whole body, not only for dementia — and are best taken with your doctor:

Check and manage blood pressure, cholesterol and blood sugar
Don't ignore hearing problems — get tested and ask about hearing aids if needed
Don't ignore vision problems — conditions such as cataracts can often be treated
Stay physically active in a way you can keep up
Stop smoking and keep alcohol moderate
Stay socially connected
Seek help for persistent low mood
Protect your head — fall prevention, helmets for cycling and sport

Where brain games fit

Brain games are not a substitute for any of the above. MIKIRI does not claim to prevent dementia or improve cognitive function. Enjoy it as a game, share scores with others, and use it as a small daily habit if it helps.

FAQ

Can dementia be prevented?: There is no guaranteed method. Addressing the 14 risk factors may delay onset or reduce risk.
Where should I start?: Get a health check that covers blood pressure, cholesterol and blood sugar, and have your hearing and vision tested. Physical activity and social connection also matter.
Do brain games help?: The evidence for dementia prevention is limited and the WHO recommendation is conditional. They do not replace exercise or managing health conditions.

Sources

Livingston G, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. Lancet. 2024;404(10452):572-628. https://doi.org/10.1016/S0140-6736(24)01296-0
World Health Organization. Dementia — fact sheet (2026). https://www.who.int/news-room/fact-sheets/detail/dementia
Japan Ministry of Health, Labour and Welfare research group (Ninomiya T). Prevalence and future estimates of dementia and MCI (2024, in Japanese). https://www.mhlw.go.jp/content/001279920.pdf
Ngandu T, et al. A 2 year multidomain intervention ... (FINGER). Lancet. 2015;385:2255-2263. https://doi.org/10.1016/S0140-6736(15)60461-5
National Center for Geriatrics and Gerontology. J-MINT study results (2024, in Japanese). https://www.ncgg.go.jp/ri/report/20240507.html
SPRINT MIND Investigators. Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia. JAMA. 2019;321(6):553-561. https://doi.org/10.1001/jama.2018.21442
Lin FR, et al. Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE). Lancet. 2023. https://doi.org/10.1016/S0140-6736(23)01406-X
WHO. Risk reduction of cognitive decline and dementia: WHO guidelines (2019). https://www.who.int/publications/i/item/9789241550543

This article is general information, not medical advice, diagnosis or treatment. If you are worried about symptoms, please talk to a doctor or a local support service.

Related guides

Play free now ▶