The Oral-Brain Axis and Neighborhood Deprivation: An Ecological Data-Warehouse Analysis of Tooth Loss, Cognitive Disability, and Mental Distress in U.S. ZIP Code Areas

Abstract Background. Oral microbial dysbiosis and periodontal disease have been linked to systemic inflammation and cognitive decline, an idea often called the oral-brain axis. Oral disease and cognitive impairment both vary with social conditions, but few analytic systems link neighborhood deprivation to oral and cognitive health across the whole country. Methods. We built a staged SQL data warehouse that combines the 2024 Area Deprivation Index (ADI; 242,297 block group records keyed by 12-digit FIPS and GISJOIN) with the CDC PLACES extract (1,171,563 rows). For four indicators (complete tooth loss in adults aged 65 and older, cognitive disability, frequent mental distress, and dental visit in the past year), ZIP Code Tabulation Area (ZCTA) prevalence was linked to county-mean ADI. We estimated Spearman correlations, ADI-quintile gradients, and population-weighted regressions with county-clustered standard errors. Microbiome data were not analyzed. Results. In 29,903 ZCTAs with all four indicators, tooth loss correlated strongly with cognitive disability (ρ = 0.83) and mental distress (ρ = 0.72), and inversely with dental visits (ρ = -0.84). From the least to the most deprived ADI quintile, tooth loss rose from 10.5% to 20.2% (ratio 1.93), cognitive disability from 13.7% to 18.2%, and mental distress from 16.0% to 18.7%, while dental visits fell from 64.4% to 50.4%. Tooth loss was associated with cognitive disability (standardized β = 0.94, 95% CI 0.91-0.96); this was unchanged after adjustment for ADI (β = 0.96), and ADI had no independent association (β = -0.04, 95% CI -0.14 to 0.06). Conclusions. Oral disease, cognitive disability and mental distress tend to occur together in U.S. ZIP areas, and all rise steeply with neighborhood deprivation. These ecological, model-based findings fit a pathway from deprivation through oral disease to cognitive and mental health problems, but they cannot establish one. The pipeline is reproducible and could later be linked to individual-level microbiome cohorts.