A major new study from the University of Gothenburg reveals an unexpected link between early rural living and type 1 diabetes (T1D). Presented at the 2025 EASD Annual Meeting in Vienna, the study suggests location during childhood may influence long-term autoimmune disease risk.
Type 1 Diabetes Is a Rising Health Concern in Sweden
Type 1 diabetes (T1D) is a chronic autoimmune condition where the immune system destroys insulin-producing beta cells in the pancreas.
This results in little to no insulin. Insulin is the hormone needed to regulate blood sugar. This leads to dangerously high glucose levels in the blood.
T1D most often begins in childhood or adolescence. It typically requires lifelong insulin therapy to manage blood sugar. This helps prevent complications.
Sweden currently has the second highest global incidence of T1D, with researchers pointing to environmental factors as a likely driver.
Unique Study Tracks Residential History from Birth to Diagnosis
Led by Samy Sebraoui and Prof. Soffia Gudbjornsdottir, the study followed 21,774 patients aged 0–30 diagnosed with T1D between 2005 and 2022.
Researchers analyzed each patient’s residential addresses from birth to diagnosis using data from the Swedish National Diabetes Register.
Rather than focusing only on where people lived at diagnosis, this study explored how early-life location affects diabetes development later on.
The goal was to identify clusters of high and low risk based on geography and land use throughout a person’s formative years.
Higher Risk Found in Rural Childhood Clusters
In a striking finding, researchers identified 11 high-risk clusters where children were more likely to develop T1D by adulthood.
All of these clusters were located in rural areas, particularly in central and northern Sweden, far from major urban centers.
Children living in these areas during their first five years faced a 20% to 2.7 times higher risk of developing T1D.
Areas dominated by forests and agricultural land showed the highest risk, suggesting an environmental link.
Urban Living Appears to Offer Protection Against T1D
In contrast, children who spent their early years in urban environments had a significantly lower risk of developing type 1 diabetes.
Researchers identified 15 low-risk clusters, all in or near cities such as Stockholm, Gothenburg, Malmö, and other mid-sized cities.
Among these, Växjö showed the lowest risk—88% lower than the national average—followed by Norrköping and Halmstad.
Land use in these areas was dominated by urban structures and open space, with fewer forests or farmland exposures.
Why Does Rural Living Increase Risk? Researchers Explore Theories
The study’s authors say the findings were unexpected and open new directions for diabetes research in environmental health and public policy.
They suggest several possible explanations, though more investigation is needed to determine the exact causes.
One hypothesis is that early exposure to pesticides or allergens in rural settings may trigger autoimmune responses in vulnerable children.
Another theory suggests that urban children face more viral infections, which may help the immune system develop protective responses.
“This is speculation for now,” the researchers caution, “but the environmental data available in Sweden offers a unique opportunity to investigate.”
First Five Years of Life Show Strongest Risk Link
The study emphasizes that the first five years of life are the most critical window in determining later risk of type 1 diabetes. During this time, the immune system is still developing and more sensitive to environmental factors like diet, pathogens, or chemicals.
“Where you live during early childhood,” the authors noted, “may have a long-lasting effect on how your immune system behaves.” This could explain why moving to a city later in life does not eliminate the elevated risk from a rural early childhood.
Data from National Registers Enabled Detailed Tracking
Sweden’s national databases gave researchers rare access to complete residential histories and medical records spanning nearly two decades.
Using zonal statistics and land cover analysis, they could match each patient’s early-life environment with diabetes diagnosis patterns. This powerful data model allowed researchers to map real-world exposure clusters based on geography, rather than rely on assumptions.
These insights could eventually guide targeted public health interventions, especially in high-risk rural regions.
Future Research Will Explore Environmental Exposures and Lifestyle Differences
The team plans further studies to examine specific environmental exposures—like pesticide use, air quality, and microbial diversity. They also want to explore how lifestyle differences between rural and urban families may influence T1D development.
“Diet, access to healthcare, antibiotic use, and time outdoors could all play a role,” said Prof. Gudbjornsdottir. “Identifying these risk and protective factors is the next step in reducing new type 1 diabetes cases.”
Rethinking the Role of Place in Diabetes Prevention
This study shifts the conversation about type 1 diabetes from genetics alone to the invisible environmental factors shaping early immune development. Its findings suggest that where a child grows up—particularly in the first five years—may be as important as family history.
As more research uncovers the role of land use, infections, and chemical exposures, public health policies may need to shift focus. Efforts to reduce harmful exposures in rural areas or enhance microbial protection in urban areas could reshape prevention strategies.
“We were surprised to see cities offer protection,” the authors conclude. “This flips the traditional view—and opens the door to deeper discovery.”
