Modifiable dementia risk factors differ substantially across nations, indicating that a uniform prevention strategy is ineffective.
An analysis of 214,000 older adults worldwide, presented by Emma Nichols, PhD, of the University of Southern California at the Alzheimer’s Association International Conference, identified both distinct and shared risk patterns.
Low educational attainment affected 85.6% of individuals in China versus 12.0% in the United States. Conversely, obesity prevalence was 44.9% in the U.S. but only 13.3% in India.
Even with varied prevalence rates, cardiovascular risk factors — including high cholesterol, hypertension, and diabetes — as well as lifestyle behaviors such as smoking and alcohol consumption, frequently co-occurred. Additionally, hearing loss, visual impairment, and low education were commonly observed together.
Nichols noted that over half of participants presented with at least two risk factors, and in 11 countries or regions, the proportion with four or more risk factors surpassed 20%.
The results were published in *Lancet Healthy Longevity*.
Nichols emphasized that understanding the geographic distribution and variation of dementia risk factors is essential for developing effective policies and programs to reduce the overall burden.
She noted that this research provides the most comprehensive international dataset on regional variations in dementia risk factors, highlighting both significant differences and common patterns across settings.
According to Nichols, this information enables governments, health systems, and communities to design more effective prevention strategies that address not only individual risk factors but also broader social and structural determinants.
Michal Schnaider Beeri, PhD, of Rutgers University, and Yian Gu, MD, MS, PhD, of Columbia University, highlighted the study’s direct implications for dementia prevention.
Beeri and Gu observed that the consistent appearance of cardiovascular, behavioral (smoking and heavy alcohol use), and sensory‑social clusters provides empirical support for multidomain intervention models, suggesting that prevention strategies tailored to these clusters could be both efficient and necessary.
It remains uncertain whether interventions based on these empirically identified clusters would surpass the effectiveness of existing multidomain approaches employed in the POINTER and FINGER trials, they noted.
The cross‑sectional design also limits the ability to assess how risk profiles evolve over time, they added.
In 2024, the *Lancet* Commission identified 14 risk factors associated with dementia, with most evidence derived from high‑income countries, revealing a knowledge gap regarding risks in other regions.
Using the Gateway to Global Aging platform, Nichols and colleagues integrated harmonized survey data collected between 2009 and 2023 from 214,251 participants across 11 long‑term aging studies in 14 locations — including the United States, England, Ireland, Northern Ireland, four European regions, Korea, Mexico, China, Malaysia, Brazil, and India — with U.S. data drawn from the Health and Retirement Study.
The researchers examined 12 of the *Lancet* Commission’s risk factors that were widely available across the studies — namely low education, hearing loss, elevated LDL cholesterol, depression, physical inactivity, diabetes, smoking, hypertension, obesity, excessive alcohol consumption, social isolation, and vision loss — and assessed their prevalence and co‑occurrence patterns.
The analysis was limited to the risk factors outlined in the *Lancet* Commission report, Nichols noted, with future updates expected to incorporate additional variables as new evidence emerges.
To facilitate comparative analysis, the researchers employed binary categorizations of each risk factor; however, continuous measures such as pack‑years of smoking can yield more nuanced insights in certain contexts.
