The policy exposome of dementia: Gaps, opportunities, and research agenda.

Government policies targeting key risk factors for cognitive decline are potential levers for preventing or delaying dementia. Policy is therefore a central component of the exposome-the cumulative exposures shaping dementia risk across the life course. While extensive research links individual risk factors to dementia, less attention has been paid to how public policies structure these risks. We introduce the concept of the policy exposome and summarize findings from a structured expert consultation conducted by the Gateway Exposome Coordinating center (GECC) to identify priority policy research domains. We argue that systematic collection and harmonization of policy data across countries and sub-national regions can enable causal research on dementia. We propose a tiered research framework to guide policy data collection, prioritizing education, tobacco and alcohol control, air pollution, and old-age social assistance. Using tobacco control as a case study, we illustrate how policies can be operationalized as exposures linkable to dementia outcomes.