Relationship of socioeconomic status to olfactory function

Abstract

Socioeconomic status can significantly impact health. To what degree education and other socioeconomic factors influence the chemical sense of olfaction is not clear. Most studies that have assessed such influences come from countries lacking large disparities in education and income and generally view such measures as nuisance variables to be controlled for statistically. In this study, we evaluated the influences of education and income on odor identification in a diverse sample of subjects from Brazil, a society where large disparities in both income and education are present. The 40-item University of Pennsylvania Smell Identification Test (UPSIT) was administered to 1572 healthy Brazilian citizens with no self-reported olfactory or gustatory deficits and for whom detailed socioeconomic and educational status data were obtained. Univariate and multivariate models were employed to examine the influence of socioeconomic status on the test scores. After controlling for age, sex, ethnicity, and smoking behavior, income and educational level were positively and independently related to the olfactory test scores (respective ps < 0.001 & 0.01). Both linear and quadratic functions described the relationship between the UPSIT scores and the levels of education and socioeconomic status. Individuals of lower socioeconomic status performed significantly worse than those of higher socioeconomic status on 20 of the 40 odorant items. This study demonstrates socioeconomic status is significantly associated with influence the ability to identify odors. The degree to which this reflects differential exposures to xenobiotic agents, cultural differences, familiarity with odors or their names, cognitive development, or other factors requires further investigation.