Smoking cessation improves olfactory functions.

Objectives: The aim of this study was to investigate changes in olfactory function after smoking cessation.
Methods: We conducted a cross-sectional study involving 28 volunteers who were admitted to the smoking cessation section of our hospital. Olfactory tests were performed immediately before smoking cessation and 45 days after smoking cessation. The duration of smoking and the number of cigarettes smoked per day were noted.
Results: The mean duration of smoking was 25.5 ± 12 years, and the participants smoked 21.6 ± 6.6 cigarettes per day. There was a significant improvement in odor discrimination, odor identification, and TDI scores (i.e., the total score of odor threshold, odor discrimination, and odor identification tests) 45 days after smoking cessation (P = .003, P = .002, and P < .001, respectively). Furthermore, a statistically significant negative correlation was found between the duration of cigarette smoking and the Sniffin' Sticks olfactory tests performed after smoking cessation, namely odor discrimination, odor identification, and TDI (P = .008, P = .002, P = .001, respectively).
Conclusion: A significant improvement was observed in odor discrimination, odor identification, and TDI scores after smoking cessation. However, this improvement was inversely associated with the duration of smoking, indicating that a longer duration of smoking may result in an insufficient improvement after smoking cessation.
Level of Evidence: 4 Laryngoscope, 130:E35-E38, 2020.
(© 2019 The American Laryngological, Rhinological and Otological Society, Inc.)