TORONTO, Canada—A groundbreaking study analyzing data from over 5 million older Americans has found that those who migrate within the U.S. have significantly better health outcomes than those who remain in their birth state, offering compelling evidence of a "healthy migrant effect" within U.S. borders.
Published in the Journal of Ethnic and Migration Studies, the study examined the prevalence of five types of disability among Americans aged 65 and older: serious vision and hearing problems, cognitive impairment, limitations in daily activities (ADLs), and physical limitations such as difficulty walking or climbing stairs.
The researchers found that older adults who had relocated to a different U.S. state were significantly less likely to report all five disabilities compared to those who still lived in their natal state, even after accounting for age, sex, and race.
"This study provides the first large-scale evidence that internal migration in the U.S. is linked to better health in later life," said coauthor Katherine Ahlin, a graduate of the Factor-Inwentash Faculty of Social Work (FIFSW) at the University of Toronto. "We found that older adults who stayed in their birth state had up to 22% higher odds of disability than internal migrants."
Importantly, controlling for education levels substantially reduced—but did not eliminate—this health advantage. The researchers suggest that individuals may move away from the state they were born in for post-secondary educational opportunities and those with more education may find better employment opportunities if they are geographically mobile.
"Educational attainment appears to play a dual role—both increasing the likelihood of migration and offering protection against disability," noted co-author Alyssa McAlpine, an FIFSW graduate. "However, internal migrants remained healthier even when we adjusted for education, which suggests that other factors like self-selection are also at play."
Perhaps most strikingly, individuals from abroad who migrated to the U.S. had lower odds of disability compared to internal migrants when their level of education was taken into account. After adjusting for education, age, sex, and race, international immigrants had between 7% and 33% lower odds of four types of disabilities than internal migrants: hearing problems, severe vision problems, cognitive impairments and mobility problems.
"This stronger health advantage among immigrants points to a more intense selection process where unhealthy individuals are less likely to overcome the multiple challenges of international migration," said Professor Esme Fuller-Thomson, senior author and Director of the Institute for Life Course and Aging at the University of Toronto. "Barriers such as cost, distance, and immigration policies likely reinforce this selection effect."
The authors suggest that the findings may be partially explained by both self-selection (healthier individuals choosing to migrate) and reverse migration (less healthy individuals returning to their place of origin). While these effects have been studied in international contexts, the study expands the discussion to include internal migration within high-income countries like the U.S.
Despite limitations, including lack of data on timing or reasons for migration, the study makes a significant contribution to public health research. It urges policymakers and researchers to consider migration history in studies of aging and health, as mobility may signal both opportunity and resilience.
