As populations grow older, dementia has become one of the greatest health challenges facing the world. Families often spend years caring for loved ones with memory loss and declining independence.
Because treatments remain limited, preventing dementia before it begins has become a major goal for researchers.
A new investigation led by the University of Southern California suggests that prevention should not look the same everywhere.
The study was presented at the Alzheimer’s Association International Conference 2026 and published in The Lancet Healthy Longevity. It examined more than 214,000 older adults from 14 countries and regions.
Most earlier dementia studies were carried out in wealthy nations such as the United States and countries in Western Europe.
The research team wanted to know whether those findings also applied to low-income and middle-income countries. To answer this question, they worked with researchers from Brown University and Johns Hopkins University.
The scientists examined 12 lifestyle and health factors linked with dementia. They also looked at how these factors changed according to age, sex and education. Finally, they studied how often several risks appeared together in the same person.
The comparison revealed that every country had its own health profile. Some populations faced much higher levels of low education, while others struggled more with obesity or cardiovascular disease. These differences mean that a prevention campaign successful in one country may have only a limited effect somewhere else.
Even so, there were encouraging signs of common patterns. Heart-related problems frequently occurred together, while unhealthy habits such as smoking and drinking also tended to cluster. This means health services may be able to reduce several risks through coordinated programs instead of separate ones.
Emma Nichols, the study’s lead author, said the similarities were just as interesting as the differences. They show that although countries have unique challenges, some shared strategies may still work when they focus on related conditions rather than isolated diseases.
The findings also carry a hopeful message for older adults and younger people alike. Dementia risk builds over many years, so improving health at any stage of life may make a difference. Managing blood pressure, staying physically active, treating hearing problems and maintaining social connections are examples of healthy steps that may help.
The researchers plan to include more countries and explore additional risk factors such as sleep as new information becomes available. Expanding the database will provide a more complete picture of dementia risk around the world.
This research is valuable because it recognises that global health problems often require local solutions. A strength of the study is its very large international sample, but further studies are still needed to confirm how changing these risk factors affects dementia rates over time.
Overall, the findings provide strong support for designing prevention programs that reflect each country’s unique health needs while continuing to promote healthy living for everyone.
If you care about brain health, please read studies about inflammation that may actually slow down cognitive decline in older people, and low vitamin D may speed up cognitive decline.
For more health information, please see recent studies about common exercises that could protect against cognitive decline, and results showing that this MIND diet may protect your cognitive function, prevent dementia.
