Does Wearing Perfume Affect How We Perceive Other Odors?

In sensory evaluation, where people assess aromas and tastes, participants may be asked not to wear perfume or cologne. This avoids interference between their fragrance and the odor of the sample being evaluated. But does that fragrance also affect the wearer’s own sense of smell?

A study published in 2022 by Thadeus L. Beekman and colleagues sought experimental evidence for this practice. When the same people took olfactory tests without perfume and while wearing it, performance differed in detecting weak odors and distinguishing odors. However, identifying what an odor was did not differ significantly: the effects varied by test.

Detecting an odor, distinguishing a difference, and identifying its source

The researchers examined three aspects of smell with Sniffin’ Sticks, a test using pen-like devices that release odors.

The first was detection threshold: how faint an odor a person can notice. Detecting very weak odors indicates greater sensitivity. In this test, higher threshold scores indicate the ability to detect more dilute odors. It is important to distinguish the direction of the test score from that of a physical concentration threshold, which runs the other way.

The second was discrimination, the ability to distinguish odors. Someone may notice that two odors differ without being able to name them. The third, identification, asks what an odor is. Although we may describe all of these as having a good nose, detecting weak stimuli, distinguishing differences, and identifying an odor can be examined separately.

The same 19 people compared no perfume with two amounts

The analysis included 19 people without professional sensory-evaluation training. Their mean age was 33, and people reporting diminished or difficult smelling before participation were excluded. Everyone attended three sessions one week apart and experienced all three conditions: no perfume, three sprays, and ten sprays. Condition order was balanced and randomized across participants.

Everyone used the same fragrance, Marc Jacobs Decadence eau de parfum, rather than selecting a favorite. It was chosen because earlier research had found its perceived gender association relatively neutral.

The perfume was not applied directly to skin. Immediately before testing, it was sprayed onto the chest area of an apron in a separate room, and the participant wore that apron. Three sprays corresponded to approximately 0.162 g and ten to approximately 0.540 g. Preliminary testing rated these amounts as just-about-right and excessive, respectively. Those labels describe evaluations under the study’s preparation conditions, not recommended everyday amounts.

Participants were asked to arrive without their own fragrance and to refrain from eating, drinking, and smoking for two hours before testing. Tests were conducted one-to-one with a researcher in ventilated rooms, in the order of threshold, discrimination, and identification. Participants were blindfolded during threshold and discrimination tasks.

Even three sprays changed performance in detecting weak odors

Mean threshold scores were 7.89 without perfume, 5.95 with three sprays, and 3.67 with ten sprays. Every pairwise comparison differed significantly, with greater perfume amounts associated with poorer detection of dilute odors. Even the condition rated just-about-right did not yield the same performance as no perfume.

Mean discrimination scores were 12.00 without perfume, 10.68 with three sprays, and 10.26 with ten. Only the comparison between no perfume and ten sprays was significant. Performance with three sprays was numerically intermediate but differed significantly from neither no perfume nor ten sprays. It therefore cannot be said that three sprays definitively reduced discrimination too.

Identification performance did not differ significantly across the three conditions. The combined TDI score, summing all three tasks, was 33.05 without perfume, 29.05 with three sprays, and 26.57 with ten. No perfume scored significantly higher than both perfume conditions, while three and ten sprays did not differ significantly. Since a total score can conceal differences between individual abilities, the separate task results also matter.

Two possible explanations proposed by the authors

The authors first considered olfactory adaptation: reduced sensitivity or response to an odor after continued exposure. Another possibility was masking, in which the worn perfume obscured the weak test odors, especially under the stronger fragrance condition. The experiment did not disentangle how much adaptation and masking each contributed.

Threshold testing came first after participants put on the apron. Given this sequence, the authors suggested that effects might occur after relatively short exposure of just a few minutes. However, the experiment did not compare time courses, so it did not establish how many minutes it takes for effects to begin or when performance returns after perfume is removed.

To explain the nonsignificant identification result, the authors suggested that identification odors might be less susceptible because they were stronger and more varied than those used in the other tasks. They also discussed earlier research indicating different cognitive processes in discriminating odors and identifying them. These are hypotheses explaining the results, not mechanisms established by this experiment.

Support for sensory-evaluation practice, and questions for future research

The study directly showed that wearing perfume can change the wearer’s own olfactory test performance. For detecting weak odors in particular, differences appeared even at an amount not judged excessive in preliminary testing. The authors interpreted this as evidence supporting the practice of asking sensory-evaluation participants to avoid perfume. It provides a reason to consider the evaluator’s own fragrance as part of test conditions when the aim is to characterize the sample itself.

The study did not, however, evaluate the taste or liking of actual foods. Effects on retronasal olfaction, the perception of aromas traveling into the nose from the mouth while eating, also remain a question for future work. Although the authors anticipated effects in trained assessors, that was not directly established in these participants.

The authors also noted that using one shared perfume on an apron may have made participants perceive it as an environmental odor rather than their usual personal fragrance. Further studies are needed to establish whether the same results occur when people wear a familiar perfume themselves, change application locations or clothing, or share a space with someone else wearing perfume.

Summary

Wearing perfume can affect perception of other odors. In this experiment involving 19 people, evidence appeared in weak-odor detection and, under the stronger perfume condition, odor discrimination. Avoiding perfume when participating in sensory evaluation may therefore also help reduce effects on the assessor’s own olfaction.

At the same time, identification did not differ significantly, and detected effects varied by task. This study does not determine recommended daily spray counts or long-term effects on smell. It provides experimental grounds for paying attention to one’s own fragrance when evaluating scents.

References

Authors: Thadeus L. Beekman, Kaushik Luthra, Shady Afrin Jeesan, Rebecca Bowie, Han-Seok Seo
Article: Should Panelists Refrain from Wearing a Personal Fragrance Prior to Sensory Evaluation? The Effect of Using Perfume on Olfactory Performance
Journal: Foods 11(3), 428 (2022)
Published: February 1, 2022
DOI: 10.3390/foods11030428
Full original article: Publisher’s article page
Original article license: Creative Commons Attribution 4.0 (CC BY 4.0).