Study finds dementia risk factors differ across countries

A major international study has found that the most common risk factors for dementia vary dramatically between countries, indicating that a single global prevention strategy will not be effective. The research, presented on July 13, 2026, at the Alzheimer's Association International Conference in London and published in The Lancet Healthy Longevity, analyzed data from more than 214,000 older adults across 14 countries and regions.

The study, led by researchers from the University of Southern California with colleagues from Brown University and Johns Hopkins University, examined 12 modifiable risk factors identified by the Lancet Commission on dementia. These included low education, hypertension, smoking, high cholesterol, obesity, physical inactivity, depression, hearing loss, vision loss, diabetes, excessive alcohol use, and social isolation.

The analysis revealed stark contrasts in the prevalence of specific risks. For instance, low education was a factor for 85.6% of older adults in China, compared to just 12.0% in the United States. Conversely, high body mass index (BMI) affected 44.9% of Americans but only 13.3% of people in India. These findings underscore that prevention...