Self-Reported Olfactory Dysfunction and Diet Quality: Findings From the 2011–2014 National Health and Nutrition Examination Survey (NHANES)

OBJECTIVES: To identify associations of self-reported olfactory dysfunction (OD) with attributes of diet quality in a nationally-representative sample of US adults. METHODS: In this cross-sectional study, we utilized self-reported taste and smell, and dietary data collected from participants 40 years and older (n = 6356) in the NHANES 2011–2014. In the home-interview, a taste and smell questionnaire asked about smell-related problems, treatments and related conditions. Dietary information was collected by trained dietary interviewers using an in-person 24-h dietary recall interview and an automated multi-pass method. Self-reported OD was based on 3 questions, and defined as affirmative response to either a smell problem in the last 12 months, worse ability to smell since age 25, or smelling phantom odors. Diet quality was assessed using the Healthy Eating Index 2015 (HEI-2015) and its adequacy and moderation components (higher scores indicating higher diet quality). Other qualitative attributes included energy density of all foods (kcal/g), % energy from fat, and added sugar. Independent associations between self-reported OD and dietary attributes were estimated with survey-weighted linear regression models adjusting for age, gender, race/ethnicity, education, income-poverty ratio, and chronic disease score (based on reported diabetes, cancer, stroke and heart attack). RESULTS: The prevalence of OD was 22.3% (95% CI: 20.4%--24.2%) and the average HEI-2015 score was 53.2 (0.4 SE). Compared to those without OD, adults with OD had higher energy density diets and higher % of energy from total fat, saturated fat and added sugar. Adjusted βs (95% CI) reflecting mean differences between those with and without OD were 0.06 (0.00, 0.12) for energy density of foods, 0.45 (0.10, 0.80) for % energy from saturated fat, 0.94 (0.19, 1.69) for % energy from total fat, and 0.96 (0.27, 1.65) for % energy from added sugar. Additionally, OD was significantly associated with lower scores on the moderation component of the HEI-2015 [βs (95% CI) = −0.62 (−1.19, −0.05). CONCLUSIONS: These findings may help inform dietary screening and recommendations for adults who perceive OD, including those experiencing transient or persistent smell loss with COVID-19. FUNDING SOURCES: NIDCD; NCATS.