The Impact of Electronic Cigarettes on Sense of Smell: A Comparative Analysis With Traditional Cigarettes.

Background: This study aimed to evaluate the effects of electronic cigarette (e-cigarette) use on olfactory function and compare the outcomes with traditional cigarette smokers and nonsmokers.

Methods: Participants were equally divided into 3 main groups (n=40 each): electronic cigarette users, traditional cigarette smokers, and nonsmokers. Among the e-cigarette users, 33 used liquid-based products and 7 used heated tobacco products. Olfactory function was assessed using the Sniffin' Sticks Extended Test, which measures odor threshold, discrimination, and identification scores. The combined threshold-discrimination-identification (TDI) score was used to quantify overall olfactory performance. Statistical analysis was conducted using one-way ANOVA followed by Tukey post hoc tests.

Results: Traditional smokers exhibited the lowest olfactory performance, with significantly reduced TDI, threshold, and identification scores compared with both e-cigarette users and nonsmokers (P<0.05). E-cigarette users demonstrated significantly better olfactory scores than traditional smokers but poorer performance than nonsmokers, although the difference between e-cigarette users and nonsmokers was not statistically significant (P=0.100). No significant differences were observed between the groups in terms of odor discrimination scores. E-cigarette use was associated with less severe olfactory impairment than traditional smoking, but still showed a trend toward reduced function compared with nonsmokers.

Conclusions: These findings suggest that while e-cigarettes may be less detrimental to olfaction than traditional cigarettes, they are not without risk. Further longitudinal studies are warranted to evaluate the long-term effects of e-cigarette use on the olfactory system.