Safety-critical odor identification failure and cognitive performance in older U.S. adults: a cross-sectional NHANES analysis

OBJECTIVE: Olfactory dysfunction is linked to cognitive decline, but the cognitive significance of failing to identify safety-critical odors is unclear. METHOD: This cross-sectional National Health and Nutrition Examination Survey 2013-2014 study examined associations between missed smoke/natural gas odors and Digit Symbol Substitution Test (DSST), Animal Fluency, and Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Delayed Recall scores among 1677 adults aged ≥60 years using survey-weighted regression. RESULTS: After demographic and clinical adjustment, each additional missed warning odor was associated with lower DSST (β = -4.77; 95% CI: -6.78 to -2.76), Animal Fluency (β = -0.96), and CERAD scores (β = -0.68). The DSST association remained significant after adjustment for general olfactory performance (β = -4.06; p = .022). Among participants missing ≥1 warning odor, 447/511 (87.5%) reported no smell problem. CONCLUSIONS: Safety-critical odor failure may capture cognitive information beyond global olfactory performance.