Use of the Diet History Questionnaire III to determine the impact of dysosmia on dietary quality.

Background: Dysosmia could alter dietary quality through mechanisms including changes in appetite, food choice, and subsequent nutritional intake. However, there are few studies that directly assess olfactory performance and dietary quality. In this pilot study, we aimed to measure dietary quality in patients with dysosmia compared with controls with normosmia.

Methods: Community-dwelling adults prospectively underwent olfactory testing using the Sniffin' Sticks test from which composite threshold, discrimination, and identification (TDI) scores were used to identify patients with dysosmia (TDI <31) and controls with normosmia (TDI ≥31). Participants completed the Diet History Questionnaire III (DHQ III), a standardized and validated tool for nutritional assessment developed by the National Institutes of Health. The Healthy Eating Index (HEI) was calculated to determine compliance with the US Dietary Guidelines for Americans.

Results: Sixty patients were enrolled, including 29 patients with dysosmia and 31 controls with normosmia with no difference in age or sex among groups. A significant correlation between TDI score and HEI component score was seen for protein (r = 0.256; p = 0.048), dairy (r = 0.285; p = 0.027), and saturated fat (r = -0.262; p = 0.043) scores. Compared with controls with normosmia, patients with dysosmia were found to have less total protein and total dairy intake, as well as less total saturated fat intake.

Conclusions: This study found significantly altered nutritional quality in patients with reduced olfactory function, including decreased intake of protein, dairy, and saturated fats. These findings are relevant given the high prevalence of dysosmia in the aging population and previous studies showing associations with mortality.