Dementia Risk: New Cases Could Double Worldwide by 2050
Updated: 3 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer
Dementia risk varies around the world. An analysis published October 12, 2026, found that about 10 in every 1,000 older adults develop dementia each year, with higher rates in women and in low- and middle-income countries. New cases could rise from about 11.4 million in 2023 to 24.7 million a year by 2050.
Dementia risk is not the same everywhere. A large new analysis published on October 12, 2026, in JAMA Neurology found that about 10 in every 1,000 older adults develop dementia each year, that women are affected more often than men, and that rates are higher in low- and middle-income countries. Because the world's population is getting older, the researchers project that new dementia cases could rise from about 11.4 million in 2023 to 24.7 million a year by 2050 [1][2]. The good news: many of the factors that shape dementia risk can be changed.
What the research says
The number of people living with dementia is expected to nearly triple. A Global Burden of Disease analysis estimated that people with dementia worldwide would rise from 57.4 million in 2019 to 152.8 million in 2050, while age-standardised prevalence stayed about the same — meaning the growth comes mainly from population growth and ageing, not from each person's risk rising (GBD 2019 Dementia Forecasting Collaborators, The Lancet Public Health, 2022).
Treating high blood pressure is linked to fewer dementia cases. A meta-analysis of 12 randomized trials with 92,135 participants found that lowering blood pressure with medicine was linked to a lower risk of dementia or cognitive impairment (7.0% vs 7.5% over about 4 years; odds ratio 0.93) (Hughes et al., JAMA, 2020).
Using hearing aids is linked to less cognitive decline. Across 8 studies with 126,903 people who had hearing loss, hearing aid users had a 19% lower risk of long-term cognitive decline than people whose hearing loss was not corrected (Yeo et al., JAMA Neurology, 2023).
Key takeaways
About 9.7 new dementia cases occur per 1,000 person-years in people studied worldwide (roughly 10 per 1,000 older adults followed for one year) [1].
Women had a higher rate than men: 10.6 vs 8.6 per 1,000 person-years [1].
Rates were higher in low- and middle-income countries (13.6) than in high-income countries (8.3) [1].
New cases could reach 24.7 million a year by 2050, mostly because more people are living to older ages — this projection assumes rates stay the same [1][2].
Dementia risk is partly modifiable: blood pressure, hearing, physical activity, smoking, diabetes and other factors matter [4][5][6].
What did the new dementia study find?
The study pooled individual data from 22 population-based studies that followed 38,418 people in 18 countries and territories across six continents. All of the studies were part of an international research group called COSMIC (Cohort Studies of Memory in an International Consortium). Over 287,632 person-years of follow-up, 3,001 participants developed dementia, based on clinical diagnoses [1].
A "person-year" simply means one person followed for one year. So a rate of 9.7 per 1,000 person-years means that, among 1,000 older adults followed for a year, about 10 would be expected to develop dementia.
The researchers adjusted the numbers to the world's 2023 age and sex structure so the results can be compared fairly. Then they applied those rates to the expected population in 2050 [1].
Group | New dementia cases per 1,000 person-years |
|---|---|
All participants (worldwide estimate) | 9.7 |
Women | 10.6 |
Men | 8.6 |
Low- and middle-income countries | 13.6 |
High-income countries | 8.3 |
Source: Vella et al., JAMA Neurology, 2026 [1].
Why is dementia risk higher in women?
This study shows that women had a higher rate of new dementia, but it was not designed to explain why [2]. Women tend to live longer, and dementia risk rises with age, especially after 65 [5]. However, the rates in this study were already adjusted for age, so longer life does not seem to be the whole story.
The research team said menopause, unequal access to education and work, and heart and metabolic factors such as body weight and physical activity deserve more study [2]. The World Health Organization also notes that women are more affected by dementia overall and provide about 70% of the care hours for people living with it [6].
Why are rates higher in lower-income countries?
Most earlier dementia estimates relied heavily on data from wealthy countries. This study deliberately included more data from low- and middle-income countries, where the rate of new cases was about 1.6 times higher than in high-income countries [1].
The authors did not prove the cause. They suggested that differences in health, education, income and environment may all play a part [2]. Many of these overlap with known dementia risk factors, such as less schooling, untreated high blood pressure, diabetes and air pollution [5][6].
Is dementia risk rising for each person?
Not necessarily. This is an important point that is easy to miss in the headlines.
The 2050 projection assumes that the rate of new cases stays the same as today [1]. The big increase in numbers happens mainly because there will be many more older adults. An earlier global analysis reached a similar conclusion: the number of people with dementia was forecast to nearly triple, but the age-adjusted rate stayed about stable, with growth driven mainly by population growth and ageing [3].
In other words, the total burden on families and health systems is likely to grow a lot, even if your own dementia risk at a given age does not change.
Can you lower your dementia risk?
There is no sure way to prevent dementia, but research points to steps that are linked to lower risk [5]. Some risk factors cannot be changed. Others can.
Risk factors you cannot change | Risk factors you may be able to change |
|---|---|
Older age (risk rises especially after 65) | High blood pressure, high cholesterol and diabetes |
Family history | Smoking and heavy alcohol use |
Down syndrome | Physical inactivity and an unhealthy diet |
— | Untreated hearing or vision loss |
— | Depression, poor sleep and sleep apnea |
— | Head injuries and air pollution |
Source: Mayo Clinic [5] and World Health Organization [6].
Here is what the evidence suggests you can do:
Know and treat your blood pressure. In randomized trials, lowering blood pressure with medicine was linked to a small but real reduction in dementia or cognitive impairment [4].
Get your hearing checked. Hearing aid use was linked to a 19% lower risk of long-term cognitive decline in people with hearing loss [7]. These were mostly observational studies, so they show a link, not proof of cause.
Stay active in body and mind. Regular exercise, reading, puzzles and social contact are recommended ways to support brain health [5].
Manage diabetes and cholesterol, and do not smoke. These protect your blood vessels, including those that supply your brain [5][6].
Look after your sleep and mood. Seek help for depression and get evaluated if you snore loudly or stop breathing during sleep [5].
You can read more in our guides to Alzheimer's disease and vascular dementia.
What are the limits of this study?
The cohorts began recruiting between 1990 and 2011, so today's rates may differ [1].
The 2050 number is a projection that assumes rates will not change; better prevention could lower it [1].
Data were available from 18 countries and territories, so many regions are still not represented [1].
The study describes patterns. It does not show what causes the differences between women and men or between countries [2].
When should you talk to a doctor?
See a doctor if you or a loved one notice memory loss that others point out, trouble finding words, confusion about time or place, or new difficulty with planning and reasoning [5]. Some factors linked to memory problems, such as certain medicines, low vitamin levels, depression and sleep problems, can be addressed, so an early check-up matters [5].
Frequently asked questions
Does age affect dementia risk?
Age is a key risk factor that cannot be changed. Dementia risk rises with age, especially after 65, but dementia is not a normal part of ageing [5].
Are women more likely to get dementia?
In this new study, women had a higher age-adjusted rate of new dementia than men (10.6 vs 8.6 per 1,000 person-years). The reasons are not yet clear and need more research [1][2].
Will dementia cases really double by 2050?
The study projects that new cases could rise to 24.7 million a year by 2050 if current rates stay the same. The increase is mainly due to population ageing [1][2].
Can lowering blood pressure reduce dementia risk?
Yes, modestly. A meta-analysis of randomized trials found that blood pressure-lowering medicine was linked to fewer cases of dementia or cognitive impairment [4].
Do hearing aids help prevent dementia?
People with hearing loss who used hearing aids had a 19% lower risk of long-term cognitive decline in a large meta-analysis, but more randomized trials are needed [7].
Health information, not medical advice
Health information, not medical advice. This article is for general education and does not replace advice from your own doctor. If you are worried about your memory or your dementia risk, please speak with a qualified health professional.
Sources
Vella AS, et al. Global Incidence of All-Cause Dementia: A Meta-Analysis. JAMA Neurology. 2026. Published online October 12, 2026. PMID 42862582. https://doi.org/10.1001/jamaneurol.2026.3540
UNSW Sydney Newsroom. New yearly dementia cases to double by 2050: study. UNSW Sydney. October 13, 2026. https://www.unsw.edu.au/newsroom/news/2026/10/new-dementia-cases-to-hit-24-7-million-annually-by-2050--study
GBD 2019 Dementia Forecasting Collaborators. Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019. The Lancet Public Health. 2022;7(2):e105-e125. PMID 34998485. https://doi.org/10.1016/S2468-2667(21)00249-8
Hughes D, et al. Association of Blood Pressure Lowering With Incident Dementia or Cognitive Impairment: A Systematic Review and Meta-analysis. JAMA. 2020;323(19):1934-1944. PMID 32427305. https://doi.org/10.1001/jama.2020.4249
Mayo Clinic Staff. Dementia - Symptoms and causes. Mayo Clinic. June 7, 2025. https://www.mayoclinic.org/diseases-conditions/dementia/symptoms-causes/syc-20352013
World Health Organization. Dementia (fact sheet). World Health Organization. July 3, 2026. https://www.who.int/news-room/fact-sheets/detail/dementia
Yeo BSY, et al. Association of Hearing Aids and Cochlear Implants With Cognitive Decline and Dementia: A Systematic Review and Meta-analysis. JAMA Neurology. 2023;80(2):134-141. PMID 36469314. https://doi.org/10.1001/jamaneurol.2022.4427
About the author: Dr. Baraa Alnahhal, MD, is a medical doctor and the founder of Rinnit. Dr. Baraa Alnahhal reviews new medical research and translates it into clear, evidence-based health information for everyday readers.
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