Where You Live May Shape Your Dementia Risk More Than Scientists Realized - SciTechDaily

What the report says

SciTechDaily reported that a large international study led by researchers at the University of Southern California found that preventable or manageable dementia risk factors differ substantially by country and region. The analysis drew on data from more than 214,000 older adults in 14 locations, collected between 2009 and 2023, and was presented at the Alzheimer’s Association International Conference 2026 in London. The work was also published in The Lancet Healthy Longevity.

The study examined 12 modifiable risk factors identified by the Lancet Commission on dementia, including limited education, hypertension, smoking, hearing loss, depression, physical inactivity and social isolation. SciTechDaily reported sharp differences in prevalence: low education was found among 85.6% of older adults in China compared with 12.0% in the United States, while high BMI was reported in 44.9% of U.S. participants and 13.3% of participants in India.

At the same time, the researchers found some recurring global patterns. Cardiovascular-related risks such as high cholesterol and high blood pressure often clustered together, while smoking and drinking tended to appear in another grouping. Lead author Emma Nichols of USC said the similarities in how risks were patterned across settings were notable and could influence how prevention efforts are designed.

The findings matter because much dementia-prevention evidence has historically come from wealthier countries, especially the United States and Western Europe. According to the report, the study suggests governments and health systems may need locally tailored prevention strategies rather than a single global approach, while also considering combined interventions for related risks such as diabetes, hypertension and cholesterol. Researchers plan to expand future analyses as more standardized country data become available.