Parsing Intra- and Inter-Individual Covariation Between the Sensory Attributes and Appeal of E-Cigarettes: Associations and Gender Differences

Effects of a fruit-ice combination flavor on appeal and sensory experience of vaping and moderation by preexisting e-cigarette flavor preference

E-cigarettes with ice flavors, which are products with a cooling agent added to a characterizing flavor (e.g., grape-ice), are widely sold. Whether ice flavors appeal to only those who already use them or a to wider population is not widely understood. This secondary analysis of a clinical laboratory experiment tested effects of experimental exposure to e-cigarettes with fruit-ice versus other flavors on the appeal and sensory attributes of vaping and whether fruit-ice effects are moderated by preexisting e-cigarette flavor preference. In a controlled double-blind within-subject randomized online experiment, adults who currently use e-cigarettes, N = 85, M (SD) = 35.5 (13.2) years, 50% female, 54.3% White, self-administered e-liquids varying in flavors (fruit-ice [grape + menthol], tobacco-only, dessert-only [caramel], and fruit-only [strawberry]). Participants rated each product's appeal (liking, disliking, willingness to use again) and sensory attributes (sweetness, smoothness, harshness, bitterness, and coolness). In the overall sample, fruit-ice flavor produced (a) higher appeal, sweetness, smoothness, and coolness and lower bitterness and harshness compared to tobacco and dessert-only flavors and (b) higher coolness and lower sweetness than fruit-only flavors. The appeal-enhancing effect of fruit-ice (vs. tobacco and dessert-only flavors) was stronger among those with preexisting preferences for menthol/mint, fruit, and ice flavors, but not for those who typically used tobacco-only flavors. Our findings suggest that restrictions on fruit-ice-flavored e-cigarettes may reduce the appeal of vaping, particularly among vapers with preferences for products with cooling, fruit, and/or sweet sensory attributes. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Reprint of: Sex differences in appeal, reward, and sensory experience of E-cigarette flavors among adults who smoke cigarettes

OBJECTIVE

Flavors enhance nicotine e-cigarette appeal by altering sensory experience. Females may be more sensitive to tobacco-associated cues and uniquely affected by flavor. The current study is an exploratory analysis to examine differences by sex on reward, appeal, and sensory experience of popular e-cigarette flavors.

METHODS

Adults (N = 121) who use cigarettes (≥1 cigarette/day) were enrolled in a laboratory study in which they vaped four e-cigarette flavors (tobacco, cherry, menthol, vanilla; in separate lab sessions) in one of two freebase nicotine concentrations (6 mg/ml,18 mg/ml). Following exposures, participants rated e-cigarette reward using the Drug Effects Questionnaire (DEQ), flavor and overall e-cigarette appeal using Labeled Hedonic Scales (LHS), and intensity of flavor, irritation, coolness, fruitiness, and sweetness using Generalized Labeled Magnitude Scales (gLMS). Linear mixed models were conducted for outcomes to analyze effects of sex, flavor, and sex x flavor interaction.

RESULTS

For DEQ ratings, there was a trend (p = .08) toward a sex x flavor interaction, in which menthol flavor produced more reward than other flavors for females, but not males. For LHS ratings, there was a significant sex x flavor interaction (p = .03) for overall e-cigarette experience with females but not males rating menthol higher than other flavors. All gLMS scales but irritation showed that females generally had greater differences between flavors compared to males (ps ≤ 0.03).

CONCLUSION

Menthol in e-cigarettes may play an important role in mediating appeal and/or reward among females. This may be due in part to their ability to better detect sensory effects of e-cigarettes.

Sex differences in appeal, reward, and sensory experience of E-cigarette flavors among adults who smoke cigarettes

OBJECTIVE

Flavors enhance nicotine e-cigarette appeal by altering sensory experience. Females may be more sensitive to tobacco-associated cues and uniquely affected by flavor. The current study is an exploratory analysis to examine differences by sex on reward, appeal, and sensory experience of popular e-cigarette flavors.

METHODS

Adults (N = 121) who use cigarettes (≥1 cigarette/day) were enrolled in a laboratory study in which they vaped four e-cigarette flavors (tobacco, cherry, menthol, vanilla; in separate lab sessions) in one of two freebase nicotine concentrations (6 mg/ml,18 mg/ml). Following exposures, participants rated e-cigarette reward using the Drug Effects Questionnaire (DEQ), flavor and overall e-cigarette appeal using Labeled Hedonic Scales (LHS), and intensity of flavor, irritation, coolness, fruitiness, and sweetness using Generalized Labeled Magnitude Scales (gLMS). Linear mixed models were conducted for outcomes to analyze effects of sex, flavor, and sex x flavor interaction.

RESULTS

For DEQ ratings, there was a trend (p = .08) toward a sex x flavor interaction, in which menthol flavor produced more reward than other flavors for females, but not males. For LHS ratings, there was a significant sex x flavor interaction (p = .03) for overall e-cigarette experience with females but not males rating menthol higher than other flavors. All gLMS scales but irritation showed that females generally had greater differences between flavors compared to males (ps ≤ 0.03).

CONCLUSION

Menthol in e-cigarettes may play an important role in mediating appeal and/or reward among females. This may be due in part to their ability to better detect sensory effects of e-cigarettes.

Sex Differences in E-Cigarette Use and Related Health Effects

BACKGROUND

Electronic cigarettes (e-cigarettes) comprise a variety of products designed to deliver nicotine, flavorings, and other substances. To date, multiple epidemiological and experimental studies have reported a variety of health issues associated with their use, including respiratory toxicity, exacerbation of respiratory conditions, and behavioral and physiological effects. While some of these effects appear to be sex- and/or gender-related, only a portion of the research has been conducted considering these variables. In this review, we sought to summarize the available literature on sex-specific effects and sex and gender differences, including predictors and risk factors, effects on organ systems, and behavioral effects.

METHODS

We searched and selected articles from 2018-2023 that included sex as a variable or reported sex differences on e-cigarette-associated effects.

RESULTS

We found 115 relevant studies published since 2018 that reported sex differences in a variety of outcomes. The main differences reported were related to reasons for initiation, including smoking history, types of devices and flavoring, polysubstance use, physiological responses to nicotine and toxicants in e-liquids, exacerbation of lung disease, and behavioral factors such as anxiety, depression, sexuality, and bullying.

CONCLUSIONS

The available literature supports the notion that both sex and gender influence the susceptibility to the negative effects of e-cigarette use. Future research needs to consider sex and gender variables when addressing e-cigarette toxicity and other health-related consequences.

Flavor science in the context of research on electronic cigarettes

Thousands start smoking or vaping daily, despite long-standing efforts by public health authorities to curb initiation and use of nicotine containing products. Over the last 15 years, use of electronic nicotine delivery systems has increased dramatically, with a diverse range of products on the market, including pod-based, disposable, and refillable electronic cigarettes (eCigs). Originally intended for harm reduction and smoking cessation, eCigs may encourage nicotine use among never smokers, given the vast range of appealing flavors that are available. To better understand abuse liability and to facilitate appropriate regulations, it is crucial to understand the science of flavor, and flavor perception within the context of eCig use. Here, we (a) provide a brief primer on chemosensory perception and flavor science for addiction and nicotine researchers, and (b) highlight existing some literature regarding flavor and nicotine use, with specific attention given to individual differences in perception, and interaction between different sensory modalities that contribute to flavor. Dramatic increases in use of eCigs highlights the importance of flavor science in contemporary addiction research, both with regards to public health and regulatory efforts. Other recent work summarizes findings on flavored e-liquids and eCig use, but none have focused explicitly on chemosensory processes or flavor perception as they relate to appeal and use of such products. We argue flavor science needs to be considered as perceptual and behavioral phenomena, and not merely from analytical, toxicological and pharmacological perspectives; we help address this gap here.

Chemosensory Contributions of E-Cigarette Additives on Nicotine Use

While rates of smoking combustible cigarettes in the United States have trended down in recent years, use of electronic cigarettes (e-cigarettes) has dramatically increased, especially among adolescents. The vast majority of e-cigarette users consume "flavored" products that contain a variety of chemosensory-rich additives, and recent literature suggests that these additives have led to the current "teen vaping epidemic." This review, covering research from both human and rodent models, provides a comprehensive overview of the sensory implications of e-cigarette additives and what is currently known about their impact on nicotine use. In doing so, we specifically address the oronasal sensory contributions of e-cigarette additives. Finally, we summarize the existing gaps in the field and highlight future directions needed to better understand the powerful influence of these additives on nicotine use.