A new study published in the Lancet Regional Health, Western Pacific looked at country-specific modifiable dementia risk factors.
“Our study examined how modifiable risk factors for dementia vary across 32 countries in the Western Pacific Region,” study author Claire V. Burley told us. “We wanted to quantify what proportion of dementia cases in each country could be attributed to factors like physical inactivity, low education, diabetes, hearing loss, smoking, and obesity, and whether a one-size-fits-all prevention approach is appropriate for such a diverse region.”
The research team expected to find variation between countries given the region’s diversity, but they anticipated the differences would be more modest. Previous work by Clarke and colleagues had documented varying risk factor profiles across the region, so the team hypothesized that prevention potential would also differ, particularly between countries at different income levels.
“The Western Pacific Region currently has 20 million people living with dementia, and by 2050 it’s projected to have the world’s largest burden at over 76 million cases,” Burley told us. “Despite this, most dementia prevention research has focused on high-income Western populations. Only eight of the region’s 37 countries have a national dementia action plan. We saw a clear need for country-specific evidence to guide prevention efforts.”
The researchers calculated population attributable fractions (PAFs) for nine modifiable risk factors using country-level prevalence data and established relative risk estimates. PAFs provide information on what proportion of dementia cases could theoretically be prevented if a given risk factor were eliminated. The researchers then compared these across countries and income groups to identify patterns.
“Study results showed that eliminating seven core modifiable risk factors could prevent 20 to 35% of dementia cases across the region,” Burley told us. “Diabetes, hearing loss, and smoking were the top contributors region-wide. However, the most striking finding was the variability between countries.”
Low education accounted for up to 7.3% of dementia burden in some lower-middle-income countries but only about 1.3% in wealthier ones. Depression showed the opposite pattern, contributing more in high-income countries. Country-specific priorities also differed. Smoking reduction would have the greatest impact in China, while increasing physical activity would yield the largest benefit in New Zealand.
“We were surprised by the sheer magnitude of variation, particularly for low education and obesity,” Burley told us. “The income-related gradient for low education was especially striking and highlights how deeply historical inequalities in schooling access can shape long-term dementia burden. We were also struck by how consistently high diabetes was across all income groups, suggesting it is a truly region-wide driver of dementia risk.”
Burley believes the findings make a strong case that dementia prevention in this region cannot rely on global averages. She believes all countries should prioritize diabetes prevention, hearing care, and tobacco control.
“Beyond that, strategies need to be tailored,” Burley told us. “Lower-income countries should focus on improving educational access and hypertension management, while higher-income countries should integrate mental health services more effectively. The 24 countries without a national dementia strategy now have an evidence base to develop targeted plans.”
Burley also emphasized that dementia is not inevitable. A significant proportion of cases are linked to factors we can act on today, however, prevention potential requires investment in health systems, education, and culturally appropriate interventions.
“Future research should focus on testing these tailored approaches and generating region-specific data to refine our estimates further,” Burley told us.
