The role of flavors in vaping initiation and satisfaction among U.S. adults

Longitudinal examination of ENDS characteristics, flavors, and nicotine content for cigarette cessation: Findings from PATH waves 5-6

BACKGROUND

A subpopulation of adults who smoke cigarettes use electronic nicotine device systems (ENDS) for cigarette cessation. This study examined the relationship between ENDS flavors, device types, and nicotine concentration with past month cigarette abstinence among adults using ENDS for cigarette cessation.

METHODS

We used the Population Assessment of Tobacco and Health (PATH) Study (waves 5 and 6) to identify adults who self-reported using ENDS to quit cigarettes at baseline (wave 5) and investigated their cigarette abstinence at follow-up (wave 6) [n = 1252]. Measures assessed include ENDS features (flavors, device types, nicotine concentration) at baseline and past-month abstinence from cigarette smoking at follow-up. Weighted descriptive analysis was used, and multivariable logistic regression models examined ENDS features associated with past-month cigarette abstinence, adjusting for demographic factors and tobacco dependence at baseline.

RESULTS

Most participants used disposable devices (37.2 %; 95 % CI:33.2-41.5), followed by refillable tanks (30.2 %; 95 % CI:26.2-34.5). Additionally, fruit (41.3 %; 95 % CI:37.3-45.5), followed by menthol (19.1 %; 95 % CI:16.2-22.4), and tobacco (18.5 %; 95 % CI:15.5-22.1) were the most common flavors. The most common nicotine concentration used was 1-6 mg/ml (38.8 %; 95 % CI:34.6-43.2). Furthermore, in the adjusted model, daily ENDS users at baseline had 86 % (95 % CI:1.08-3.18) higher odds of past month cigarette abstinence at follow-up, than individuals who indicated 'not at all' to the current use of ENDS at baseline. There were no significant differences by preferred flavors, device type and nicotine concentrations (p-values > 0.05).

CONCLUSIONS

Daily ENDS users had higher odds of quitting cigarettes compared to those who stopped using ENDS. However, the type of device, flavoring, and nicotine concentration used by ENDS users were not associated with past-month cigarette abstinence at follow-up two years later.

Perceptions of FDA-authorized e-cigarettes and use interest among young adults who do not use tobacco

INTRODUCTION

It is unclear how young adults who do not use tobacco perceive FDA-authorized e-cigarettes for market entry. This study explored the perceptions and use interests of FDA-authorized e-cigarettes among this population to inform policy decision-making.

METHODS

We conducted in-depth interviews with young adults in the US, aged 18-29 years, who do not use tobacco (n=25). Participants viewed images of FDA-authorized e-cigarettes and discussed their perceptions and interest in using these products. We used reflexive thematic analysis to analyze interview data.

RESULTS

Many participants stated that they were not interested in using FDA-authorized e-cigarettes because they had little interest in using e-cigarettes in general. Additionally, almost all participants found the tobacco flavor and product design of these products unappealing, which further added to their disinterest. Most reported high trust in the FDA and its authorization process for e-cigarette market entry and considered FDA-authorized e-cigarettes safe to use. Most considered FDA-authorized products less harmful than other (unauthorized) e-cigarettes they saw in daily life but were not more interested in using the authorized products. When given the hypothetical scenario where FDA-authorized products come with a variety of fruit and candy flavors, most participants still expressed little interest in using them, mainly due to the high perceived harm from using any e-cigarette products.

CONCLUSIONS

Although non-tobacco-using young adults in our study reported low interest in using FDA-authorized e-cigarettes for market entry and e-cigarettes in general, the FDA is recommended to continue to evaluate the impact of flavorings and packages on e-cigarette product appeal to reduce e-cigarette use among young people. The FDA should also examine strategies to effectively communicate the purpose of FDA authorization to the public and emphasize that it does not mean these products are 'approved' or safer than unauthorized products.

Non-tobacco nicotine E-cigarette use and flavored E-cigarette use among young adults in the United States

BACKGROUND

E-cigarette flavors can create sensations of sweetness and coolness while masking the aversiveness of nicotine. Recently, non-tobacco nicotine (NTN) products were introduced to the market, but little is known about flavors in NTN e-cigarette use. We examined associations between flavors (i.e., sweet, mint/menthol) and susceptibility to and use of NTN e-cigarettes.

METHODS

1239 US young adults (18-25 years) completed an anonymous, online survey in Fall 2021. The analytic sample included 520 participants who had used e-cigarettes and heard of NTN. Multinomial logistic regression models analyzed associations of flavored e-cigarette use (sweet and mint/menthol) with NTN e-cigarette use status (i.e., current [past-month] use, past [ever but not current] use, susceptible to use, and non-susceptible to use [reference]).

RESULTS

Overall, 46.2% of participants reported current NTN use, 14.8% reported past use, 16.7% were susceptible to use, and 22.3% reported no susceptibility. Participants reported dual-use of sweet and mint/menthol NTN e-cigarette flavors (56.5%), sweet flavors use (24.8%), and mint/menthol flavor use (1.7%). Ever dual use of sweet and mint/menthol flavors was associated with current (OR = 9.64, 95%CI: 3.21-28.98) and past NTN e-cigarette use (8.30, [2.10-32.80]). Ever sweet flavor use was associated with current NTN use (3.80, 95%CI: 1.44-10.03) and susceptibility to future use (4.25, [1.53-11.81]). Similar findings were observed for mint/menthol flavors (current: 5.03, [1.41-17.99]; susceptible: 5.65, [1.64-19.51]).

CONCLUSION

The use of sweet and mint/menthol flavors was significantly associated with NTN e-cigarette use among US young adults, highlighting the need for ongoing surveillance of flavored NTN e-cigarettes and appropriate regulations to discourage use.

The Flavoring Agent Ethyl Vanillin Induces Cellular Stress Responses in HK-2 Cells

Flavored e-cigarettes are a popular alternative to cigarette smoking; unfortunately, the extrapulmonary effects are not well-characterized. Human proximal tubule cells were cultured for 24 or 48 h with 0-1000 µM ethyl vanillin (ETH VAN) and cytotoxicity evaluated. Mitochondrial health was significantly diminished following 48 h of exposure, accompanied by significantly decreased spare capacity, coupling efficiency, and ATP synthase expression. ETH VAN at 24 h inhibited glycolysis. The endoplasmic reticulum (ER) stress marker C/EBP homologous protein (CHOP) was increased at 100 μM relative to 500-1000 μM. The downstream proapoptotic marker cleaved caspase-3 subsequently showed a decreasing trend in expression after 48 h of exposure. The autophagy biomarkers microtubule-associated proteins 1A/1B light chain 3 (LC3B-I and LC3B-II) were measured by Western blot. LC3B-II levels and the LC3B-II/LC3B-I ratio increased at 24 h, which suggested activation of autophagy. In contrast, by 48 h, the autophagy biomarker LC3B-II decreased, resulting in no change in the LC3B-II/LC3B-I ratio. Mitophagy biomarker PTEN-induced putative kinase 1 (PINK1) expression decreased after 48 h of exposure. The downstream marker Parkin was not significantly changed after 24 or 48 h. These findings indicate that the flavoring ETH VAN can induce energy pathway dysfunction and cellular stress responses in a renal model.

Fruit flavors in electronic cigarettes (ECIGs) are associated with nocturnal dry cough: A population longitudinal analysis

Evidence from in vitro and animal models has identified the pulmonary toxicity of flavors in electronic cigarettes (ECIGs); however, less is known from epidemiological studies about the effects of flavors in the respiratory health. This study examined the longitudinal association between exposure to ECIGs flavors and nocturnal dry cough among ECIGs users. A secondary analysis of data from the Population Assessment of Tobacco and Health Study (2014-2019) was conducted. The study population included adults who provided information (n = 18,925) for a total of 38,638 observations. Weighted-incidence estimates and weighted- generalized estimating equation models were performed to assess unadjusted and adjusted associations. The weighted incidence proportion (WIP) of nocturnal dry cough was significantly higher among current (WIP:16.6%; 95%CI 10.5, 21.2) and former fruit flavored ECIGs users (WIP:16.6%; 95%CI 11.3, 21.9) as compared to non-ECIGs users (WIP:11.1%; 95%CI 10.6, 11.6). Current ECIGs users of fruit flavors showed 40% higher risk of reporting cough than non-ECIGs users (aRR:1.40, 95%CI 1.01, 1.94). Former ECIGs users of multiple flavors and other flavors had 300% and 66% higher risk to develop cough, respectively (aRR:3.33, 95%CI 1.51, 7.34 and aRR:1.66, 95%CI 1.0.9, 2.51), relative to non-ECIGs users. We observed a significantly higher risk of developing nocturnal dry cough in the past 12 months in current and former ECIGs users of fruit flavors and in former ECIGs users of multiple flavors. To the extent that cough may serve as an early indicator of respiratory inflammation and potential disease risk, the association between ECIGs use and cough raises potential concerns.

Would banning menthol cigarettes, flavored cigars, and flavored e-cigarettes prompt users to seek illicit channels for obtaining them in the United States?

BACKGROUND

Banning flavors in tobacco and nicotine products may reduce youth initiation and prompt quit attempts but such bans may lead to illicit markets. We examined how likely current users would be to seek flavored products from illicit channels under various ban scenarios.

METHODS

Cross-sectional surveys of 2552 current users of menthol cigarettes or flavored cigars and 2347 users of flavored e-cigarettes were conducted between 2021 and 2022 in the United States. For each ban scenario, respondents reported if they would have intentions to seek the banned flavored products from any illicit channels and identified the specific illicit channel they would consider. Logistic regressions were used to estimate how the likelihood of having intentions to seek illicit channels was associated with demographics, ban scenarios, and status of tobacco use.

RESULTS

Under various ban scenarios, 24-30% of people who smoked said they would seek illicit channels to obtain the banned products compared with 21-41% of dual users and 35-39% of users of flavored e-cigarettes. Online retailers were favored by people who smoked while users of flavored e-cigarettes favored local retailers. Heavy users were more likely to say they would try illicit channels. Under bans restricting more types of flavored tobacco products, users would be less likely to try illegal channels.

CONCLUSIONS

A significant proportion of users of flavored tobacco and nicotine products would not reject using illicit banned products. Tailored programs are needed to apply to the groups with a higher risk of seeking illicit channels for banned products.

e-Cigarette Tobacco Flavors, Public Health, and Toxicity: Narrative Review

BACKGROUND

Recently, the US Food and Drug Administration implemented enforcement priorities against all flavored, cartridge-based e-cigarettes other than menthol and tobacco flavors. This ban undermined the products' appeal to vapers, so e-cigarette manufacturers added flavorants of other attractive flavors into tobacco-flavored e-cigarettes and reestablished appeal.

OBJECTIVE

This review aims to analyze the impact of the addition of other flavorants in tobacco-flavored e-cigarettes on both human and public health issues and to propose further research as well as potential interventions.

METHODS

Searches for relevant literature published between 2018 and 2023 were performed. Cited articles about the toxicity of e-cigarette chemicals included those published before 2018, and governmental websites and documents were also included for crucial information.

RESULTS

Both the sales of e-cigarettes and posts on social media suggested that the manufacturers' strategy was successful. The reestablished appeal causes not only a public health issue but also threats to the health of individual vapers. Research has shown an increase in toxicity associated with the flavorants commonly used in flavored e-cigarettes, which are likely added to tobacco-flavored e-cigarettes based on tobacco-derived and synthetic tobacco-free nicotine, and these other flavors are associated with higher clinical symptoms not often induced solely by natural, traditional tobacco flavors.

CONCLUSIONS

The additional health risks posed by the flavorants are pronounced even without considering the toxicological interactions of the different tobacco flavorants, and more research should be done to understand the health risks thoroughly and to take proper actions accordingly for the regulation of these emerging products.

An Estimation of the Prevalence of Smoking and e-Cigarette Use among U.S. Adults If Menthol Cigarettes and Flavored Cigars Are Banned

INTRODUCTION

People's reaction to the FDA's ban on flavored cigarettes and cigars may be modified by a concurrent ban on flavored e-cigarettes. We aim to estimate the prevalence of smoking and e-cigarette use among U.S. adults under various ban scenarios.

METHODS

We collected the reactions of people who used cigarettes, cigars, and e-cigarettes reactions to three hypothetical ban scenarios, (1) restricting menthol cigarettes and flavored cigars only, or (2) further restricting e-cigarettes with any flavors except menthol or tobacco, or (3) further restricting e-cigarettes with all flavors. The above data were analyzed to identify determinants of reactions and to estimate and calibrate the probabilities of quitting and switching to non-flavored cigarettes and cigars. Afterward, the probabilities were applied to 2018-2019 TUS-CPS respondents to estimate the prevalence of smoking and e-cigarette use.

RESULTS

Compared with the baseline, the prevalence of smoking decreased from 12.6% to 10.5%, and e-cigarette use increased from 2.6% to 3.8% in Scenario No.1. In Scenario No.2 and No.3, the prevalence of smoking was 10.5% and 10.7%, and the prevalence of e-cigarette use were 3.1% and 2.4%, respectively. For black people, the prevalence of smoking decreased from 14.2% in baseline to 8.1%-8.8% in three scenarios.

CONCLUSIONS

The result indicated that for a ban on menthol cigarettes and flavored cigars, a concurrent ban on flavored e-cigarettes with an exemption of menthol flavor could be more effective in encouraging people to quit smoking. Black people may see a disproportionate benefit from all ban scenarios compared with other race/ethics groups.

Does sensation-seeking behavior influence the patterns of flavored e-cigarette use? A cross-sectional study among Indonesian adolescents and young adults

BACKGROUND

The variety of available flavors in e-cigarettes may be a driver for young people to start using these products. The objectives of our study were to examine the relationship between sensation-seeking behavior and e-cigarette use, and to identify the predictors of flavor use patterns among adolescents in Indonesia.

METHODS

Students aged 15 to 24 years participated from randomly selected high schools and universities in Indonesia. Participants answered questions about their demographic data, e-cigarette use, conventional cigarette use, and sensation-seeking. Flavor preferences were identified from eight different flavor categories. Multivariate multinomial regression analysis was employed to predict conventional cigarette and e-cigarette use among students. A latent class analysis was conducted to determine the number of latent classes of flavor use.

RESULTS

One thousand six hundred high school and university students, with a mean age of 18.2 years (SD 2.19), were recruited between March and August, 2023. Conventional cigarette use in the past 30 days was higher (16.3%) compared to e-cigarette use (13.3%, p = 0.017), with approximately 8.5% of students were being dual users. Higher levels of sensation-seeking significantly increased the odds of being a current e-cigarette user (OR = 2.54, 95%CI 1.99-3.25) and a current conventional cigarette smoker (OR = 2.38, 95%CI 1.85-3.07). Three groups of flavor classes were identified: 1) primarily menthol flavor users (14%), who had a strong association with current conventional cigarette use; 2) experimenters, who mostly preferred fruit-flavored e-cigarettes (76%); and 3) the multi-flavor user group (10%), who had a higher sensation-seeking tendency.

CONCLUSIONS

Flavors, especially menthol and fruit flavors, attract youth, broaden the e-cigarette audience and are particularly appealing to high sensation-seekers. Banning these flavors could significantly deter e-cigarette initiation among youth.

Should menthol e-cigarettes be banned? Reaction of adult smokers and users of e-cigarettes to hypothetical bans

INTRODUCTION

This study examines how current smokers using menthol cigarettes or flavoured cigars, and current users of flavoured e-cigarettes may respond to three hypothetical flavour-ban scenarios: (1) banning only menthol cigarettes and flavoured cigars; (2) also banning e-cigarettes with any non-tobacco flavours except menthol; and (3) also banning e-cigarettes with any non-tobacco flavours, including menthol.

METHODS

Recruited from mTurk, respondents were asked if they would quit all tobacco-nicotine use or continue or start using products that were still legally available. The patterns of responding to each ban scenario, for both flavoured smokers and users of non-tobacco flavoured e-cigarettes, were summarised. Multinomial logistic regressions were used to estimate associations between demographics, smoking or e-cigarette use status and reactions to a ban.

RESULTS

A ban on menthol cigarettes and flavoured cigars would lead to 12%-20% of flavoured smokers trying to quit all tobacco use and 32%-52% switching to non-flavoured smoking, with the remaining switching to e-cigarettes or other products. Compared with a ban on only menthol cigarettes and flavoured cigars, also banning flavoured e-cigarettes would increase the likelihood of quitting all tobacco-nicotine use (OR=2.58) but also increase the likelihood of switching to non-flavoured smoking (OR=1.74).

CONCLUSIONS

Our results indicate that a ban on menthol cigarettes and flavoured cigars would decrease smoking. However, it is unclear if adding a ban of menthol e-cigarettes would lead to additional benefits because without menthol e-cigarettes as an alternative, some smokers and e-cigarette users may switch to non-flavoured tobacco smoking, rather than quit all tobacco use.

Use patterns of flavored non-cigarette tobacco products among US adults, 2010-2019

OBJECTIVE

Flavored non-cigarette tobacco product (NCTP) use is common among US adult tobacco users. To update the estimates of use patterns of flavored NCTPs, this study assessed current NCTP use among adults by flavor use and flavor categories from 2010 to 2019.

METHODS

We analyzed data from the 2010-2019 Tobacco Use Supplement to the Current Population Survey to estimate the weighted proportion of adult NCTP users by flavor use across survey waves. Flavor use was defined as past 30-day use of any menthol/mint or fruit/other flavors. We used the 2018-2019 data to examine the differences in demographic characteristics and tobacco use patterns among users of menthol/mint or fruit/other flavors compared to exclusive users of tobacco flavor, by product type.

RESULTS

Compared to 2014-2015, electronic nicotine delivery system (ENDS) users were more likely (79.0% vs. 66.6%, p < 0.001) to report flavor use in 2018-2019, whereas cigar (26.9% vs. 31.2%, p = 0.030) and pipe (56.3% vs. 65.5%, p = 0.015) smokers were less likely to report flavor use in 2018-2019. In 2018-2019, the most prevalent flavor categories were exclusive use of tobacco flavor among cigar (73.1%) and smokeless tobacco (48.3%) users, and use of fruit/other flavors among ENDS (64.9%) and pipe (48.4%) users. Flavored users were more likely to be young adults aged 18-24 years (cigars, ENDS, smokeless tobacco) and Non-Hispanic Black or Hispanic persons (cigars, ENDS, pipes) compared to tobacco-flavored users.

CONCLUSIONS

Flavored product use increased among adult ENDS users but decreased among cigar and pipe smokers. These findings could inform tobacco regulatory efforts concerning flavored NCTPs.

Comparative systematic review on the safety of e-cigarettes and conventional cigarettes

BACKGROUND

This systematic review evaluated the health risks of electronic cigarettes (e-cigarettes) compared to traditional cigarettes. It examines various studies and research on the subject to provide a comprehensive analysis of potential health risks associated with both smoking methods.

METHODS

The systematic review, incorporating searches in PubMed, Scopus, Web of Science, and the Cochrane Library up to July 2023, examines the results obtained in relevant studies, and provides a critical discussion of the results.

RESULTS

E-cigarettes exhibit reduced exposure to harmful toxins compared to traditional cigarettes.

CONCLUSION

However, concerns persist regarding respiratory irritation and potential health risks, especially among youth, emphasizing the need for comprehensive, long-term research and protective legislation.

Effects of Nicotine Content and Preferred Flavor on Subjective Responses to E-cigarettes: A Randomized, Placebo-controlled Laboratory Study

INTRODUCTION

Evidence suggests that e-liquid flavor and nicotine concentration are important factors in the initiation and maintenance of e-cigarette use (vaping). Flavors may increase the initiation and maintenance of vaping, and nicotine content is a factor in e-cigarette dependence and the efficacy of e-cigarettes for cigarette smoking cessation. Few human laboratory studies have assessed the joint and interactive effects of flavor and nicotine on subjective responses to e-cigarettes.

METHODS

Regular e-cigarette users (N = 89) completed a multi-session study involving a paced vaping procedure with e-liquid cartridges containing their preferred flavor (berry, menthol, or tobacco) or no flavor, with or without nicotine (18 mg). Subjective effects of vaping (satisfaction, reward, aversion, airway sensations, and craving relief) were assessed.

RESULTS

Nicotine significantly increased psychological reward and craving relief, whereas flavor significantly increased vaping satisfaction and taste. Nicotine dependence severity moderated the effect of nicotine on reward, such that those with the greatest dependence severity reported the greatest reward.

CONCLUSIONS

These findings support differential and noninteractive effects of e-liquid nicotine content and flavor on reinforcing effects of e-cigarettes.

IMPLICATIONS

E-liquid flavor and nicotine content have independent, non-interactive effects on subjective responses to vaping under controlled laboratory conditions. Among regular e-cigarette users, vaping a preferred flavor increased taste and satisfaction, but did not interact with nicotine to alter reward or craving. Further research on the ways in which these subjective effects may motivate vaping behavior among different populations of e-cigarette users would be useful to inform regulatory policy of ENDS products.

Exposure to Electronic Waterpipes Increases the Risk of Occlusive Cardiovascular Disease in C57BL/6J Mice

INTRODUCTION

It is well documented that cardiovascular disease (CVD) is the leading cause of death in the US and worldwide, with smoking being the most preventable cause. Additionally, most smokers die from thrombotic-based diseases, in which platelets play a major role. To this end, because of the proven harm of smoking, several novel tobacco products such as electronic(e)-waterpipe have been gaining popularity among different sectors of the population, partly due to their "false" safety claims. While many investigators have focused on the negative health effects of traditional cigarettes and e-cigarettes on the cardiovascular system, virtually little or nothing is known about e-waterpipes, which we investigated herein.

METHODS AND MATERIALS

To investigate their occlusive CVD effects, we employed a whole-body mouse exposure model of e-waterpipe vape/smoke and exposed C57BL/6J male mice (starting at 7 weeks of age) for 1 month, with the controls exposed to clean air. Exposures took place seven times a week, according to the well-known Beirut protocol, which has been employed in many studies, as it mimics real-life waterpipe exposure scenarios; specifically, 171 puffs of 530 ml volume of the e-liquid at 2.6 s puff duration and 17 s puff interval.

RESULTS

The e-waterpipe exposed mice had shortened bleeding and occlusion times, when compared to the clean air controls, indicating a prothrombotic phenotype. As for the mechanism underlying this phenotype, we found that e-waterpipe exposed platelets exhibited enhanced agonist-triggered aggregation and dense granule secretion. Also, flow cytometry analysis of surface markers of platelet activation showed that both P-selectin and integrin GPIIb-IIIa activation were enhanced in the e-waterpipe exposed platelets, relative to the controls. Finally, platelet spreading and Akt phosphorylation were also more pronounced in the exposed mice.

CONCLUSION

We document that e-waterpipe exposure does exert untoward effects in the context of thrombosis-based CVD, in part, via promoting platelet hyperreactivity.

A literature review addressing midwakh and e-cigarette use in the Gulf region

A notable decrease in conventional cigarette smoking has been witnessed on a global scale. However, this decrease has been accompanied by an equally striking global increase in the consumption of alternative tobacco products (ATPs), namely e-cigarettes and midwakh in the Arabian Gulf region. A literature review was used to outline the chemical composition of these two ATPs and review their impacts on health. The study was conducted using databases like PubMed, Google Scholar, MDPI, and WorldCat. The literature search included terms such as "e-cigarettes," "midwakh," "dokha," "heath impacts," "psychological effects," "social influences," and "cigarette smoking" with emphasis on literature from the Arabian Gulf region. Data shows that midwakh contains markedly high levels of tar, nicotine, and various compounds of notable effects on the human body. Similarly, it was found that e-cigarettes contain non-negligible amounts of nicotine and other chemical compounds that may not have been extensively investigated. Alarming reports of system-specific effects brought about by midwakh, and e-cigarette consumption, have been reported, although further research is needed to deduce the mechanism. We also discussed some of the social and psychological factors leading to their consumption within this population. Hence, this review raises questions around the safety of these two types of ATPs and encourages comprehensive studies globally and regionally.

Flavoring Agents in E-cigarette Liquids: A Comprehensive Analysis of Multiple Health Risks

The availability of a wide range of flavored e-cigarettes is one of the primary reasons for vaping initiation and persistent use among adolescents and young people. This plethora of flavors available on the market are crafted using different flavoring agents such as cinnamaldehyde, vanillin, benzaldehyde, ethyl maltol, menthol, and dimethylpyrazine. Recent studies have brought to light the potential risks associated with e-cigarette flavoring agents and their effects on various organ systems, both with and without nicotine. Research has demonstrated that flavoring agents can induce inflammation, endothelial dysfunction, epithelial barrier disruption, oxidative stress, DNA damage, electrophysiological alterations, immunomodulatory effects, and behavioral changes, even independently of nicotine. Notably, these negative outcomes adversely affect cardiovascular system by reducing cell viability, decreasing endothelial nitric oxide synthase, nitric oxide bioavailability, soluble guanylyl cyclase activity and cyclic guanosine monophosphate accumulation, impairing endothelial proliferation and tube formation, and altering vasoreactivity resulting in vascular dysfunction. In the heart, these agents decrease parasympathetic activity, induce depolarization of resting membrane potential, loss of rhythmicity, increase isovolumic relaxation time, and change in ventricular repolarization and ventricular tachyarrhythmias. It is found that the specific response elicited by flavoring agents in different organ systems varies depending on the flavor used, the concentration of the flavoring agent, and the duration of exposure. However, the literature on the effects of flavoring agents is currently limited, emphasizing the need for more preclinical and randomized clinical trials to gain a deeper understanding and provide further evidence of the harmful effects of flavored e-cigarette use. In summary, recent research suggests that flavoring agents themselves can have detrimental effects on the body. To fully comprehend these effects, additional preclinical and clinical studies are needed to explore the risks associated with flavored e-cigarette usage.

Hypothetical e-liquid flavor ban and opinions among vape shop retailers in the Greater Los Angeles Area

INTRODUCTION

Evaluating anticipated responses to flavor bans in the context of vape shops is needed to inform legislation and enforcement. This cross-sectional study examined vape shop retailers' opinions about the potential impacts of an e-liquid flavor ban on shop sales and customer behavior-change intentions.

METHODS

From December 2019 to October 2020 we conducted structured interviews over the phone with 46 brick-and-mortar vape shop retailers in the Greater Los Angeles Area.

RESULTS

Most participants were managers (43.5%), followed by owners (26.1%) and clerks (26.1%). More than half (52.2%) reported that sales would drop a lot if flavored e-liquids were banned in all vape shops. Controlling for store position, multivariable linear regression showed that opposition to a hypothetical ban on non-tobacco flavored e-liquids was associated with participants' opinions that customers would likely not purchase tobacco flavored e-liquids (b= -0.44, p<0.01), and would likely use combustible tobacco products (b=0.47, p<0.05).

CONCLUSIONS

In this cross-sectional study, vape shop retailers in the Greater Los Angeles Area reported that if a ban on non-tobacco e-liquid flavors occurred, they would oppose strongly, and that a ban would have a negative impact on their shop (e.g. loss in sales) and customer behavior (e.g. would replace vaping with smoking combustible tobacco products). Implications for research and practice are discussed.

Use of flavored cannabis vaping products in the US, Canada, Australia, and New Zealand: findings from the international cannabis policy study wave 4 (2021)

Background: Vaping is an increasingly popular mode of cannabis use. Few studies have characterized the role of flavors in cannabis e-liquids.Objectives: To explore the prevalence of flavored vaping liquids, including differences between countries and correlates of use.Methods: Data were from Wave 4 (2021) of the International Cannabis Policy Study with national samples aged 16-65 in Canada, the United States (US), Australia, and New Zealand. The sample comprised 52,938 respondents, including 6,265 who vaped cannabis e-liquids in the past 12-months (2,858 females, 3,407 males). Logistic regression models examined differences in the use of flavored e-liquids between countries and sociodemographic characteristics.Results: The prevalence of vaping cannabis e-liquids was highest in the US (15.3%) and Canada (10.7%) compared to Australia (4.0%) and New Zealand (3.7%). Among past 12-month cannabis consumers, 57.5% reported using flavored vaping liquids, 34.2% used unflavored vaping products and 8.3% did not know. People who vape in Australia were most likely to report using flavored liquids compared to New Zealand (OR = 2.29), Canada (OR = 3.14), and the US (OR = 3.14) (p < .05 for all). Fruit was the most reported vaping flavor (40.8%), followed by candy/dessert (20.4%) and vanilla (15.2%). Use of flavored vapes was greater among younger, ethnic minorities, female, higher education and income adequacy, and more frequent consumers (p < .05).Conclusion: Many cannabis consumers reported using flavored e-liquids, with highest levels among young people aged 16-35. Given the high prevalence of vaping in legal markets, regulators should consider the role of flavored vaping products in promoting cannabis use among this group.

Reactions to hypothetical flavor bans among current users of flavored e-cigarettes

Banning flavors in e-cigarettes and other tobacco products may decrease their use. To examine how current users of flavored e-cigarettes might react to a ban on flavored e-cigarettes when: (i) menthol flavor is banned together with other flavors, or (ii) this ban on e-cigarettes is combined with a ban on menthol cigarettes and flavored cigars. A national cross-sectional survey of 2,347 current users of flavored e-cigarettes was conducted in May 2022. For each hypothetical ban scenario, respondents reported if they would quit all tobacco product use, continue to use e-cigarettes with no flavor or flavors that were not banned, or switch to alternative tobacco products. Multinomial logistic regressions were used to estimate the associations between responses and ban scenarios, adjusting for tobacco use and demographic variables. If e-cigarettes with any flavors except menthol and tobacco were banned, the majority of current e-cigarette users would keep using e-cigarettes with no flavor or tobacco and menthol flavor. When menthol flavor was added to a ban, a greater proportion of respondents would quit all tobacco use; however, more would also switch to cigarettes or cigars. When menthol cigarettes and flavored cigars were added to a ban, those who used menthol flavor only would be less likely to switch to cigarettes and cigars. Among current e-cigarette users, the harm reduction (i.e., from quitting all use) from a ban on flavored e-cigarettes, particularly if menthol is also banned, may be outweighed by the harm increases (i.e., switching to cigarettes or cigars, or other products that are more harmful than using e-cigarettes). A concurrent ban on menthol cigarettes and flavored cigars would secure more certain net reductions to public health harms from e-cigarette use and smoking.

Vaping Dose, Device Type, and E-Liquid Flavor are Determinants of DNA Damage in Electronic Cigarette Users

INTRODUCTION

Despite the widespread use of electronic cigarettes, the long-term health consequences of vaping are largely unknown.

AIMS AND METHODS

We investigated the DNA-damaging effects of vaping as compared to smoking in healthy adults, including "exclusive" vapers (never smokers), cigarette smokers only, and nonusers, matched for age, gender, and race (N = 72). Following biochemical verification of vaping or smoking status, we quantified DNA damage in oral epithelial cells of our study subjects, using a long-amplicon quantitative polymerase chain reaction assay.

RESULTS

We detected significantly increased levels of DNA damage in both vapers and smokers as compared to nonusers (p = .005 and p = .020, respectively). While the mean levels of DNA damage did not differ significantly between vapers and smokers (p = .522), damage levels increased dose-dependently, from light users to heavy users, in both vapers and smokers as compared to nonusers. Among vapers, pod users followed by mod users, and those who used sweet-, mint or menthol-, and fruit-flavored e-liquids, respectively, showed the highest levels of DNA damage. The nicotine content of e-liquid was not a predictor of DNA damage in vapers.

CONCLUSIONS

This is the first demonstration of a dose-dependent formation of DNA damage in vapers who had never smoked cigarettes. Our data support a role for product characteristics, specifically device type and e-liquid flavor, in the induction of DNA damage in vapers. Given the popularity of pod and mod devices and the preferability of sweet-, mint or menthol-, and fruit-flavored e-liquids by both adult- and youth vapers, our findings can have significant implications for public health and tobacco products regulation.

IMPLICATIONS

We demonstrate a dose-dependent formation of DNA damage in oral cells from vapers who had never smoked tobacco cigarettes as well as exclusive cigarette smokers. Device type and e-liquid flavor determine the extent of DNA damage detected in vapers. Users of pod devices followed by mod users, and those who use sweet-, mint or menthol-, and fruit-flavored e-liquids, respectively, show the highest levels of DNA damage when compared to nonusers. Given the popularity of pod and mod devices and the preferability of these same flavors of e-liquid by both adult- and youth vapers, our findings can have significant implications for public health and tobacco products regulation.

Differentiating Reasons for Young Adult E-cigarette Use Using Maximum Difference Choice Models

INTRODUCTION

Understanding the reasons young adults use e-cigarettes (ie, vape)-and whether these motivations vary across groups-is essential for informing tobacco regulatory efforts.

AIMS AND METHODS

An online panel of young adults who vape (n = 230; age = 18-30 years) completed a maximum difference discrete choice task for 15 reasons for vaping. Over 9 choice sets, participants were presented a subset of 5 reasons and selected the most and least important. Hierarchical bayesian analysis estimated the relative importance of each reason. Latent class analysis (LCA) identified groups with similarly ranked reasons for use. Multinomial regression evaluated the association between sample characteristics and class membership.

RESULTS

Overall, relaxation had the highest probability of being the most important reason for use (14.8%), followed by harm reduction (13.2%), and flavors (10.3%). LCA identified five distinct classes, based on top reasons for use: 1. cessation (cigarette cessation [20.2%]; n = 80); 2. dependence (relaxation [20.5%] and unable to quit [19.2%]; n = 21); 3. relaxation (relaxation [20.6%]; n = 66); 4. socializing (socializing [22.2%]; n = 27); and 5. variable (boredom [10.5%] and acceptability [10.2%]; n = 36). Participants who were older, smoked cigarettes, or vaped more frequently were more likely to belong to the cessation class while those who were younger or more e-cigarette dependent were more likely to belong to the dependence class.

CONCLUSIONS

Perceived reasons why young adults vape are highly heterogeneous and dependent on the type of user. Tobacco regulatory efforts targeting distinct types of vapers are needed to minimize the adverse public health impact of vaping without compromising appeal for smoking cessation.

IMPLICATIONS

E-cigarette use remains high among young adults, with flavors, cost, and harm reduction (vs. combustible cigarettes) among the mostly commonly reported reasons for use. Yet, little is known about how relatively important these reasons are to the individual. Leveraging a maximum difference task, young adults' reasons for use were evaluated on a common interval scale and groups sharing similar reasons identified. Smoking cessation, dependence, relaxation, socialization, and boredom were respectively the most important reasons for use among five classes of vapers. E-cigarette regulatory policies should consider the distinct reasons for use as to not compromise their appeal for smoking cessation.

The impact of flavored e-cigarette bans on e-cigarette use in three US states

Introduction

Beginning in 2019, several U.S. states implemented temporary or permanent bans on the sale of flavored e-cigarettes. This study examined the impact of flavor bans on adult e-cigarette use in Washington, New Jersey, and New York.

Methods

Adults who used e-cigarettes at least once a week before the flavor bans were recruited online. Respondents reported their e-cigarette use, primarily used flavor, and ways of obtaining e-cigarettes before and after the bans. Descriptive statistics and multinomial logistic regression models were applied.

Results

After the ban, 8.1% of respondents (N=1624) quit using e-cigarettes, those primarily used banned menthol or other flavors declined from 74.4% to 50.8, those using tobacco-flavored declined from 20.1% to 15.6%, and those using non-flavored increased from 5.4% to 25.4%. More frequent e-cigarette use and smoking cigarettes were associated with being less likely to quit e-cigarettes and more likely to use banned flavors. Of those primarily using banned flavors, 45.1% obtained e-cigarettes from in-state stores, 31.2% from out-of-state stores, 32% from friends, family, or others, 25.5% from Internet/mail sellers, 5.2% from illegal sellers, 4.2% mixed flavored e-liquids themselves, and 6.9% stocked up on e-cigarettes before the ban.

Conclusions

Most respondents continued to use e-cigarettes with banned flavors post-ban. Compliance of local retailers with the ban was not high, and many respondents obtained banned-flavor e-cigarettes through legal channels. However, the significant increase in the use of non-flavored e-cigarettes post-ban suggests that these may serve as a viable alternative among those who used previously used banned or tobacco flavors.

What types of e-liquid products were more likely to offer price promotions?

INTRODUCTION

The present study empirically examined the association between price discounts and product attributes of e-liquids sold by online retailers.

METHODS

We analysed 14 000 e-liquid products from five major online e-cigarette retailers between April and May 2021 to determine the association between price discounts and product attributes such as nicotine level and form, flavour and vegetable glycerine/propylene glycol ratio. A fixed-effects model was used in the analysis and discounts were calculated in US cents/mL of e-liquid volume.

RESULTS

Out of 14 407 e-liquid products, 92.5% were offered at a discounted price. On average, the price discount for the 13 324 products that had discounts was 16.84 cents/mL across the five stores. Among the three forms of nicotine (salt, freebase and nicotine free), salt e-liquids had the highest average price discount.

CONCLUSION

Our findings suggest that e-liquids with salt nicotine have a higher average price discount when sold online, which may influence consumer purchasing behaviour. Further research is needed to assess the potential impact of these discounts on youth and adult tobacco use. Policymakers may consider implementing measures to limit online price discounts for e-liquids as a means of reducing sales among young people.

Impact of flavours, device, nicotine levels and price on adult e-cigarette users' tobacco and nicotine product choices

INTRODUCTION

To understand the impact of e-cigarette devices, flavours, nicotine levels and prices on adult e-cigarette users' choices among closed-system and open-system e-cigarettes, cigarettes and heated tobacco products (HTPs).

METHODS

Online discrete choice experiments were conducted among adult (≥18 years) e-cigarette users (n=2642) in August 2020. Conditional logit regressions were used to assess the relative impact of product attributes and the interactions between product attributes and user characteristics, with stratified analyses to examine differences by smoking status and primarily used e-cigarette device and flavour.

RESULTS

On average, participants preferred non-tobacco and non-menthol flavours most, preferred open-system over closed-system e-cigarettes and preferred regular nicotine level over low nicotine level. However, the preference varied by demographics, smoking status and the primarily used e-cigarette device and flavour. The differences in preference among products/devices were larger than the difference among flavours or nicotine levels. Participants who primarily used closed-system e-cigarettes exhibited similar preferences for closed-system and open-system e-cigarettes, but those who primarily used open-system e-cigarettes preferred much more open-system over closed-system e-cigarettes. HTP was the least preferred product, much lower than cigarettes in general, but participants living in states where IQOS is being sold had similar preferences to cigarettes and HTPs.

CONCLUSIONS

People are unlikely to switch to another product/device because of the restriction of flavour or nicotine level. If non-tobacco and non-menthol flavours were banned from open-system e-cigarettes, users may switch to menthol flavour e-cigarettes. Intervention strategies should be tailored to specific groups.

Misconceptions of Vaping Among Young Adults

Background Vaping is growing in popularity worldwide, especially among young adults. To develop effective tobacco prevention interventions, first, there must be an understanding of the attitudes and perceptions of young adults toward the use of vaping. Highlighting perception discrepancies between races may allow physicians to more effectively counsel their patients regarding the risks of vaping. Methodology We conducted an online survey using Amazon Mechanical Turk (MTurk, https://www.mturk.com/) to identify misconceptions about vaping among adults aged 18 to 24 years who currently vape. The survey consisted of 18 questions evaluating reasons for vaping, history of tobacco use, and thoughts on the adverse effects of vaping. The Penn State Electronic Cigarette Dependence Index was implemented to assess dependence. Exclusion criteria comprised respondents who did not vape and were under the age of 18 or over the age of 24. Results A total of 1,009 responses were received with 66% identifying as male (n = 667) and 33% (n = 332) identifying as female. Sixty-nine percent of patients smoked cigarettes or used another form of tobacco previously (n = 692). Of those respondents, 81% indicated that they had since quit using tobacco products (excluding vaping). Switching to vaping was the most common reason for quitting cigarettes or other forms of tobacco, with health concerns and social purposes being the second and third most common reasons provided, respectively. When asked whether vaping had negative health impacts, only 238 (24%) participants strongly agreed with this statement, while a majority (64%) neither agreed nor disagreed or only somewhat agreed. Most participants were white or Caucasian (n = 777). When asked whether smoking or vaping had more severe health implications, 55% of white or Caucasian participants, 41% of Asian participants, and 32% of black or African American participants indicated that vaping was worse than smoking cigarettes. The average Penn State dependence score was 8.7, suggesting medium dependence. Conclusions Our survey sample of 1,006 young adults who vape indicated that the majority did not perceive vaping as significantly harmful. A comprehensive smoking prevention policy, educational interventions, and quit support are needed to enhance awareness among young adults about the health effects associated with vaping. Such interventions should also consider the novel shift toward the replacement of smoking with vaping.

Flavoured and nicotine-containing e-liquids impair homeostatic properties of an alveolar-capillary cell model

Most people consider that electronic cigarettes are safer than tobacco and are marketed as quit-smoking products. The e-liquid, which usually contains propylene glycol (PG) and vegetable glycerin (VG) in different ratios, nicotine and a wide variety of flavours, is heated by a coil and the aerosol droplets are primarily delivered to the alveolar area where nicotine and other molecules cross the alveolar-capillary barrier (ACB). However, e-cigarettes effects on the ACB are not yet established. In our study, a well-characterised in vitro model of the ACB was exposed to PG and VG and to five flavoured e-liquids with and without nicotine. The vehicles, due to their hypertonic properties, modulated the ACB integrity by modifying occludin expression. Below a 10% concentration, the vehicles did not trigger oxidative stress or cell death. Different results were observed between flavoured e-liquids: while red fruits and mint-eucalyptus disrupted ACB integrity, triggered oxidative stress and cell death, blond tobacco had no worse effect compared to the vehicles. However, the addition of nicotine in the latter e-liquid increased oxidative stress and cell death compared to the vehicles. Finally, mint-eucalyptus e-liquid increased some inflammation markers. Our results revealed that e-liquids alter ACB homeostasis, depending on flavour and nicotine presence.

Flavour spectrum of the Puff family of disposable e-cigarettes

BACKGROUND

In January 2020, the US Food and Drug Administration prohibited the sale of flavours (except for menthol and tobacco) in prefilled pod devices such as JUUL to decrease youth vaping. Excluded from the prohibition were disposable devices.

OBJECTIVES

To determine the scope and scale of flavours marketed by Puff Bar, a leading disposable brand, and related products.

METHODS

Disposable e-cigarette flavours were identified via online searches encompassing vendor websites, wholesale distributors, manufacturers (eg, made-in-china.com), and social media channel, Instagram, between June and August 2020.

RESULTS

The 'Puff' brand name and iconic cloud logo appear on a variety of products of differing sizes and nicotine e-liquid volumes. Among Puff Bar and its copycats (Puff-a-Likes), 139 flavours were identified. Fruit flavours predominated comprising 82.2% of the flavour varieties (fruit 50%, fruit and menthol/mint 23.6%, and fruity drinks 8.6%). A prevalent new flavour category which combines fruit with menthol/mint (Ice) was offered in 33 varieties such as Lychee Ice, Lush Ice and Banana Ice. Disposable e-cigarette brands are undertaking measures to escape tobacco regulation (eg, non-tobacco-sourced nicotine) and flavour limitations via post-market flavour additions to unflavoured nicotine e-liquid.

CONCLUSIONS

The proliferation of flavoured disposable e-cigarette products, many of which are designed to emulate popular pod devices, illustrates that narrowly limited flavour regulations covering only a single category are destined to fail. To be effective in youth protection, flavour regulations need to apply to all recreational nicotine-containing products and need to include measures to counter post-market flavour addition.

Effects of electronic cigarette e-liquid flavouring on cigarette craving

BACKGROUND

E-liquid flavour restrictions may discourage electronic cigarette (e-cigarette) uptake among youth. However, possible unintended consequences may include reduced appeal and effectiveness of e-cigarettes for smoking cessation. Non-tobacco flavours appear to be important for smoking cessation, but how and why are currently unclear.

METHODS

We conducted an experimental study in a UK sample of adult daily smokers using an independent groups design (N=84). Participants were randomised to use an e-cigarette with nicotine-containing fruit/sweet-flavoured e-liquid (blackcurrant, strawberry, vanilla, caramel) or unflavoured e-liquid for 1 week. The primary outcomes were average, peak and cue-elicited cigarette craving (the latter was assessed using a cue exposure task). The secondary outcomes were smoking lapse occurrence, enjoyment of the e-cigarette, ease of transitioning from smoking to using an e-cigarette, intentions to continue using an e-cigarette, intentions and motivation to quit smoking, return to smoking, and continuation of e-cigarette use.

RESULTS

E-liquid flavouring did not appear to have an effect on average cigarette craving (b 0.18, 95% CI -0.44 to 0.79, p=0.57), peak cigarette craving (b -0.12, 95% CI -0.59 to 0.35, p=0.62) or cue-elicited cigarette craving (b -0.21, 95% CI -3.86 to 3.43, p=0.91). We did not find evidence of a difference in secondary outcomes.

CONCLUSIONS

We did not find evidence to suggest that nicotine-containing fruit/sweet-flavoured and unflavoured e-liquids have different effects on cigarette cravings after 1 week of use. Further research is needed to establish if differences emerge over longer periods of exposure and extend to smoking cessation outcomes.

Hypothetical flavour ban and intention to vape among vape shop customers: the role of flavour preference and e-cigarette dependence

INTRODUCTION

E-cigarette users typically initiate vaping with flavoured e-liquids. People who vape flavours tend to underestimate the harm of vaping. We examined the inter-relationship between flavour preference, vaping for cessation purposes, e-cigarette dependence, e-cigarette harm perception and purchase/use intention, given a hypothetical flavour ban. We hypothesised that non-tobacco flavour preference and vaping for cessation would be negatively associated with harm perception of e-cigarettes and intention to continue vaping if a flavour ban occurred and that these effects would be mediated by e-cigarette dependence.

METHODS

From July 2019 to March 2020, we conducted intercept interviews with 276 customers at 44 vape shops in California. The predictor variables were flavour preference and vaping for cessation. The outcome variables were harm perception of e-cigarettes and intention to purchase/use, given a hypothetical flavour ban. Multilevel structural equation modelling tested whether e-cigarette dependence mediates the effects of flavour preference on hypothetical continued vaping and purchase.

RESULTS

Those who preferred flavours showed significantly lower intention to purchase e-liquids (β=-0.28, p<0.001) and to continue vaping (β=-0.17, p=0.001), given a hypothetical flavour ban. Those who vaped for smoking cessation indicated greater intention to purchase e-liquid (β=0.10, p=0.016) and to continue vaping (β=0.17, p=0.001), given a hypothetical flavour ban. E-cigarette dependence significantly mediated these effects (ps<0.04).

DISCUSSION

Flavour preference was negatively related to intention to continue to vape within a hypothetical flavour ban. Our results also highlight the importance of e-cigarette dependence and use of e-cigarettes as smoking cessation methods. Implications for future flavour bans are discussed.

An Assessment of Vape Shop Products in California before and after Implementation of FDA and State Regulations

Vape shops specialize in sales of e-cigarettes and related products. This study examines whether vape shops adapted their products and services in response to changes in federal and state policies that affect the tobacco retail environment between 2014-2022. In this multicohort study, four waves of study data were used to examine the trends in products sold in vape shops in Southern California. Items sold were assessed through systematic store product observations and included categories of e-cigarettes, device modification equipment, and other products (e.g., Cannabidiol (CBD), paraphernalia). Descriptive statistics are reported. The availability of disposable devices increased from 18% at Wave 1 to 98% of shops at Wave 4. Pod mods were first observed in 79% of the shops beginning at Wave 3. Device modification drills later become obsolete, from 60% at Wave 1 to 0 by Wave 4; self-service sampling displays declined from 83% of shops to 9%. Vape shops did not carry CBD products until Wave 3 (2017/2018), when 19.0% of shops carried CBD products and 72.9% at Wave 4. Future research should examine how e-cigarette retailers and manufacturers respond to changing state and federal regulations to better understand the implications of regulatory efforts.

Electronic nicotine delivery systems (ENDS) flavours and devices used by adults before and after the 2020 US FDA ENDS enforcement priority: findings from the 2018 and 2020 US ITC Smoking and Vaping Surveys

Background

In February 2020, the US Food and Drug Administration (FDA) prioritised enforcement efforts against flavoured prefilled cartridge/pod electronic nicotine delivery systems (ENDS), with the exception of tobacco and menthol. This study examined changes between prepriority enforcement (2018) and early postenforcement (February–June 2020) among adults on: ENDS flavours and devices used most often; location of last purchase of fruit/other-flavoured cartridges (covered under the enforcement priority); and smoking and vaping.

Methods

Prevalence estimates came from 1608 adult frequent (≥weekly) ENDS users (current smokers (n=1072), ex-smokers (n=536)) who participated in the 2018 and/or 2020 US ITC Smoking and Vaping Surveys. Transitions between flavours/devices and changes in smoking/vaping were assessed among baseline respondents who were followed up in 2020 (n=360). Respondents self-reported the ENDS device (disposable, cartridge/pod or tank) and the flavor that they used most often: (1) tobacco flavors (tobacco/tobacco-menthol mix) or unflavored; (2) menthol/mint; (3) fruit/other flavors.

Results

Compared to 2018, in the first 5 months of the 2020 enforcement priority, there were significant increases in the prevalence of fruit/other-flavoured cartridges (7.9% to 12.4%,p=0.026) and menthol/mint cartridges (7.1% to 13.0%, p<0.01) and decreases in tobacco-flavoured tanks (15.5% to 10.0%,p=0.002) and fruit/other-flavoured tanks (38.7% to 33.6%,p=0.038). Fewer than 10% of adults used disposables in 2018 and 2020. Among the cohort sample, the most pronounced transitions between flavours/devices occurred among those who used flavoured cartridges covered under the enforcement priority (54.6% switched to a flavour and/or device excluded from enforcement). There was an increase in purchasing fruit/other-flavoured cartridges online and a decrease in retail locations except for vape shops. Overall, there were few changes in smoking and vaping behaviours.

Conclusions

Between 2018 and the early phase of the FDA’s 2020 enforcement priority, prevalence of menthol/mint and fruit/other-flavoured cartridges increased among adults. Half of vapers using cartridge flavours covered in the enforcement switched to other flavours and/or devices that were exempt, with the exception of disposables. The extent to which more comprehensive restrictions may be problematic for adults who prefer a range of ENDS flavours remains uncertain.

Impact of the FDA flavour enforcement policy on flavoured electronic cigarette use behaviour changes

INTRODUCTION

This study aims to investigate electronic cigarette (e-cigarette) use behaviour changes after the implementation of the US Food and Drug Administration (FDA) restriction on the sale of all unauthorised flavoured cartridge-based e-cigarettes other than tobacco and menthol flavour on 6 February 2020, as well as factors associated with these changes.

METHODS

Through Amazon's Mechanical Turk service, 3533 current adult flavoured e-cigarette users (who were not exclusive tobacco-flavoured or menthol-flavoured e-cigarette users) were recruited for an online survey from 8 July to 29 July 2021. Multiple logistic regression models were used to identify significant factors associated with quitting e-cigarette use, switching to other flavoured electronic nicotine delivery system (ENDS) products, switching to combustible tobacco products, switching to menthol-flavoured e-cigarettes and switching to tobacco-flavoured e-cigarettes.

RESULTS

Resulting from the FDA flavour enforcement policy, the top four e-cigarette use behaviour changes were: (1) switching to other flavoured ENDS products such as the tank system or disposable e-cigarettes (29.24%), (2) switching to menthol-flavoured pod systems (18.09%), (3) switching to combustible tobacco products (14.12%) and (4) switching to tobacco-flavoured pod systems (12.03%). There were 4.9% participants who indicated that they quit e-cigarette use. Overall, multiple factors, especially past 30-day use of certain flavours, were associated with different behaviour changes.

CONCLUSIONS

The implementation of the FDA flavour enforcement policy on cartridge-based e-cigarette was associated with significant e-cigarette behaviour changes, with multiple factors being associated with these changes. These results provide important information for future regulations of flavoured e-cigarette products.

Trends and consumption patterns in the use of e-cigarettes among adolescents and young adults in Germany (the DEBRA study)

INTRODUCTION

Considering the growing popularity and rapid evolution of e-cigarettes, we examined e-cigarette use and tobacco smoking trends, and e-cigarette consumption patterns (i.e., device type, nicotine level) among adolescents and young adults in Germany.

METHODS

Data from 26 waves of the German Study on Tobacco Use (DEBRA), a repeated cross-sectional nationwide household survey, were used to explore trends in the prevalence of ever e-cigarette use and tobacco smoking in a sample of adolescents (aged 14-17 years, N = 1,396) and young adults (aged 18-24 years, N = 4,685) between June/July 2016 and Aug/Sept 2020. Among current e-cigarette users (N = 208), consumption patterns were examined. Associations with e-cigarette use were analysed using multivariable regression.

RESULTS

Adolescent e-cigarette use increased from 9.2% in 2016 to 16.5% in 2017, decreased in 2018 to 8.3% and then gradually increased to 13.4% by 2020. Adolescent tobacco smoking followed a similar trend. Young adult e-cigarette use rates remained relatively stable at 19.1% on average, while tobacco smoking slowly declined (2016: 44.7%, 2020: 38.5%). More than half of current e-cigarette users used refillable-style e-cigarettes (59.4% adolescents; 68.4% young adults) and also smoked tobacco (62.5% adolescents; 79.4% young adults). About 41.6% of adolescents and 56.0% of young adults vaped with nicotine. Among young adults, men (OR = 1.5; 95%CI: 1.3-1.8) and former (OR = 9.6; 95%CI: 1.1-13.1) and current (OR = 10.7; 95%CI: 8.7-13.2) tobacco smokers were more likely to have vaped.

CONCLUSION

E-cigarette use continues to rise in German adolescents and young adults requiring targeted health interventions and campaigns aimed at preventing and/or reducing use in this population.

The impact of two state-level approaches to restricting the sale of flavored tobacco products

BACKGROUND

Flavored tobacco products are highly appealing to youth. The Federal government lacks a comprehensive flavored tobacco products policy and states have adopted different approaches restricting these products. This study analyzes the impact of Massachusetts' comprehensive prohibition and New Jersey's partial restriction on the sale of flavored tobacco products.

METHODS

NielsenIQ Retail Scanner data were used to construct four log per capita dependent variables: e-liquid milliliters, cigarette packs, cigars, and smokeless tobacco ounces for products flavored as fruit, menthol, mint, tobacco and other. All models used difference-in-differences regressions, with Virginia and Pennsylvania serving as controls. The models controlled for state level product prices, population percentages by race/ethnicity, proportion male, median household income, unemployment rate, minimum legal sales age, tobacco 21 policies, and cumulative cases and deaths of COVID-19; the models accounted for time-specific factors by using 4-week period fixed-effects.

RESULTS

There was a significant decrease in sales across all flavored tobacco products in Massachusetts, including fruit [-99.83%, p < 0.01], menthol [-98.33%, p < 0.01], and all other flavored [-99.28%, p < 0.01] e-cigarettes. The cigar group "all other-flavors" [-99.92%, p < 0.01] and menthol flavored cigarettes [-95.36%, p < 0.01] also significantly decreased. In New Jersey, there was a significant decrease in per capita sales of menthol-flavored e-cigarettes [-83.80%, p < 0.05] and cigar group "all other-flavors" experienced a significant increase in per capita sales [380.66%, p < 0.01].

CONCLUSIONS

This study contributes to the growing body of evidence demonstrating the impact of sales prohibitions on reducing sales of flavored tobacco products. Statewide comprehensive approaches appear more effective than partial restrictions and should be prioritized.

IMPLICATIONS

Results from this study support emerging research that demonstrates the promising effects of comprehensive flavoring sales prohibitions. This study can be used to inform future flavored tobacco product policy solutions developed by advocates and policy makers to curb overall tobacco initiation and use by youth and adults.

E-cigarette addiction and harm perception: Does initiation flavor choice matter?

Introduction

The 21^st century was marked by a dramatic increase in adolescent e-cigarette use in the United States (US). The popularity of non-traditional flavor types, including fruit and pastry, is thought to contribute toward growing product use nationally, leading to a variety of federal and state regulations limiting the use of non-traditional flavors in the US. The relationship between flavor type and increased adolescent use suggests a possible link between flavor use and addiction and harm perception. This study assessed if the flavor type used when initiating e-cigarette use predicted addiction and harm perceptions.

Methods

The study utilized data from the multi-wave youth Population Assessment of Tobacco Health Study. It explored the impact initiating e-cigarette use with traditional versus non-traditional flavor types among cigarette users on the outcome variables: e-cigarette addiction and harm perception. Both e-cigarette addiction and harm perception were measured using self-report, Likert scale questionnaires. Descriptive statistics characterized the study variables and linear regression analyses performed to test whether flavor initiation type is associated with addiction and harm perception.

Results

The study sample consisted of 1,043 youth (weighted N = 1,873,617) aged 12 to 17 years who reported at least one instance of e-cigarette use. After adjusting for age, age of onset, sex, race and annual household income there was no statistically significant difference in addiction levels between those initiating with traditional versus non-traditional flavors (p = 0.294). Similarly, traditional versus non-traditional flavor initiation did not show a statistically significant difference in adolescent e-cigarette harm perceptions (p = 0.601).

Conclusions

Traditionally flavored e-cigarette initiation produces similar risk for addiction and harm perceptions as non-traditionally flavored initiation. These findings suggest that banning non-traditional flavors alone may be ineffective in curbing e-cigarette addiction and harm perception. Additional research is needed to better understand which e-cigarette product characteristics and behaviors may be associated with greater addiction and reduced harm perceptions.

E-Cigarettes Reexamined: Product Toxicity

The introduction of e-cigarettes, or electronic nicotine delivery systems (ENDS), has been accompanied by controversy regarding their safety and effectiveness as a cessation aid and by an explosion in their use by youth. Their use does not involve the combustion of tobacco and the creation of harmful combustion products; they have been seen as a "harm reduction" tool that may be of assistance in promoting smoking cessation. Recognition that ENDS can deliver an array of chemicals and materials with known adverse consequences has spurred more careful examination of these products. Nicotine, nitrosamines, carbonyl compounds, heavy metals, free radicals, reactive oxygen species, particulate matter, and "emerging chemicals of concern" are among the constituents of the heated chemical aerosol that is inhaled when ENDS are used. They raise concerns for cardiovascular and respiratory health that merit the attention of clinicians and regulatory agencies. Frequently cited concerns include evidence of disordered respiratory function, altered hemodynamics, endothelial dysfunction, vascular reactivity, and enhanced thrombogenesis. The absence of evidence of the consequences of their long-term use is of additional concern. Their effectiveness as cessation aids and beneficial impact on health outcomes continue to be examined. It is important to ensure that their production and availability are thoughtfully regulated to optimise their safety and permit their use as harm reduction devices and potentially as smoking-cessation aids. It is equally vital to effectively prevent them from becoming ubiquitous consumer products with the potential to rapidly induce nicotine addiction among large numbers of youth. Clinicians should understand the nature of these products and the implications of their use.

The Role of Nicotine and Flavor in the Abuse Potential and Appeal of Electronic Cigarettes for Adult Current and Former Cigarette and Electronic Cigarette Users: A Systematic Review

INTRODUCTION

Many adult cigarette smokers use electronic cigarettes (e-cigarettes) to cut down on or quit smoking cigarettes. E-cigarettes with higher abuse potential and appeal might facilitate complete switching. E-liquid nicotine concentration and flavor are two of the characteristics that may affect the abuse potential and appeal of e-cigarettes. The objective of this systematic review was to compile results from survey, animal, human laboratory, and clinical studies to understand the possible effects of nicotine concentration and flavor on abuse potential and appeal of e-cigarettes in adult current and former cigarette and e-cigarette users.

AIMS AND METHODS

A comprehensive literature search was conducted in Ovid Medline and PsycINFO followed by citation tracking in Web of Science Core Collection. Peer-reviewed studies published in English between 2007 and August 2020 were selected that analyzed differences between e-liquid nicotine concentration and/or flavors, had outcome measures related to abuse potential and/or appeal, and included adult humans (18+) or animals. A total of 1624 studies were identified and screened. A qualitative synthesis of results was performed.

RESULTS

Results from 104 studies included in this review suggest that higher nicotine concentration and access to a variety of flavors are likely to be associated with higher abuse potential and appeal of e-cigarettes for adult current and former cigarette and e-cigarette users.

CONCLUSIONS

Higher nicotine concentrations and the availability of a variety of flavors in e-cigarettes might facilitate complete substitution for cigarettes. Future e-cigarette regulations should take into account their impact on smokers, for whom e-cigarettes may be a cessation tool or reduced-harm alternative.

IMPLICATIONS

E-cigarettes may provide a reduced-harm alternative to cigarettes for smokers unwilling/unable to quit or serve as a path for quitting all nicotine products. Higher nicotine concentrations and flavor variety are associated with higher abuse potential and appeal of e-cigarettes. Higher abuse potential and appeal products may help facilitate complete switching from cigarettes to e-cigarettes. Regulation of nicotine concentration and flavors aimed at decreasing naïve uptake may inadvertently decrease uptake and complete switching among smokers, reducing the harm reduction potential of e-cigarettes. Evidence-based effects of regulating nicotine concentration and flavors must be considered for the population as a whole, including smokers.

Impact of existing and potential e-cigarette flavor restrictions on e-cigarette use among young adult e-cigarette users in 6 US metropolitan areas

Given the 2020 federal restrictions on flavored cartridge-based e-cigarettes and increasing state/local flavored e-cigarette sales restrictions, this mixed-methods study examined US young adult e-cigarette users' responses to flavored e-cigarette sales restrictions (e.g., changes in use, products used, access). We descriptively analyzed Fall 2020 survey data from 726 past 6-month e-cigarette users (Mage = 24.15, 51.1% female, 4.4% Black, 10.2% Asian, 12.1% Hispanic, 35.5% sexual minority), and qualitatively analyzed Spring 2021 semi-structured interview data among 40 participants (Mage = 26.30, 35.0% female, 5.0% Black, 22.5% Asian, 12.5% Hispanic, 45.0% sexual minority). Across all participants (i.e., survey and interview participants), ≥80% most commonly used non-tobacco flavors; ≥40% used tank-based devices. Survey participants most commonly reported that the federal restrictions did not impact their use: 35.8% used available flavors (i.e., tobacco, menthol), 30.4% continued to use tank-based e-cigarettes, and 10.1% switched to tank-based e-cigarettes. Only 8.4% reduced their e-cigarette use. Among interview participants, some indicated no impact on their e-cigarette use because they stocked up or obtained flavors from alternative sources (e.g., online). Some filled their own pods with e-liquids, switched to menthol/tobacco flavors, switched e-cigarette devices or brands, and/or reduced use. Regarding the anticipated impact of comprehensive flavor restrictions, some participants reported that they would: 1) quit vaping; 2) switch to cigarettes; or 3) not change their use (e.g., stock up on flavors). The potential unintended reactions to flavored e-cigarette sales restrictions (e.g., continued use of flavored cartridge-based e-cigarettes) underscore the need for ongoing surveillance of retail and consumer behavior to inform policy and compliance/enforcement efforts.

Flavored Tobacco Product Use Among Young Adults by Race and Ethnicity: Evidence From the Population Assessment of Tobacco and Health Study

PURPOSE

Describe racial/ethnic patterns of flavored tobacco use to illuminate equity implications of flavored tobacco policies.

METHODS

Using data on US young adults (ages 18-34; n = 8,114) in the Population Assessment of Tobacco and Health Study Wave 5 (2018-2019) and survey-weighted logistic regression, we estimated any flavors (regular brand) and mint/menthol (vs. other flavors) use by race/ethnicity among cigarette, e-cigarette, cigar, blunt, hookah, smokeless tobacco, and any tobacco product users.

RESULTS

Any flavored tobacco use was common and was significantly higher for Black (75.1%; OR: 1.4; 95% CI: 1.2, 1.7) and Hispanic/Latinx (77.2%; OR: 1.4; 95% CI: 1.1, 1.7) users than White users (73.5%). The most pronounced difference across products was in menthol cigarette use between Black and White smokers (OR: 4.5; 95% CI: 3.5, 5.9). Among flavored product users, mint/menthol use was significantly higher for Latinx blunt and hookah users.

DISCUSSION

Racial/ethnic disparities in flavored tobacco use include and extend beyond menthol cigarettes. Comprehensive flavored tobacco restrictions that include mint/menthol and non-cigarette products will likely have more equitable impact.

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.

Systematic review on e-cigarette and its effects on weight gain and adipocytes

Smoking and obesity are leading causes of morbidity and mortality worldwide. E-cigarette which was first introduced in 2000s is perceived as an effective alternative to conventional tobacco smoking. Limited knowledge is available regarding the risks and benefits of e-cigarettes. This study systematically reviews the current literature on the effects of e-cigarettes on body weight changes and adipocytes. The search was performed using OVID Medline and Scopus databases and studies meeting the inclusion criteria were independently assessed. This review included all English language, empirical quantitative and qualitative papers that investigated the effects of e-cigarettes on bodyweight or lipid accumulation or adipocytes. Literature searches identified 4965 references. After removing duplicates and screening for eligibility, thirteen references which involve human, in vivo and in vitro studies were reviewed and appraised. High prevalence of e-cigarette was reported in majority of the cross sectional studies conducted among respondent who are obese or overweight. More conclusive findings were identified in in vivo studies with e-cigarette causing weight decrease. However, these observations were not supported by in vitro data. Hence, the effect of e-cigarette on body weight changes warrants further investigations. Well-designed population and molecular studies are needed to further elucidate the role of e-cigarettes in obesity.

E-Cigarette Flavors, Devices, and Brands Used by Youths Before and After Partial Flavor Restrictions in the United States: Canada, England, and the United States, 2017‒2020

Objectives. To examine the impact of US restrictions implemented in February 2020 prohibiting flavors other than menthol and tobacco in cartridge-based e-cigarettes. Methods. We analyzed 5 cross-sectional waves of the International Tobacco Control Policy Evaluation Project Youth Tobacco and Vaping Surveys, conducted online with youths aged 16 to 19 years in the United States, Canada, and England, for differences in usual e-cigarette flavor, device, and brand reported by past-30-day vapers (n = 9512) before (2017, 2018, 2019), during (February 2020), and after (August 2020) implementation of US flavor restrictions. Results. In August 2020, 78.7% of vapers in the United States reported using a flavor prohibited in cartridges or pods, versus 86.3% in Canada (adjusted odds ratio [AOR] = 1.73; 95% CI = 1.25, 1.40) and 79.8% in England (AOR = 1.10; 95% CI = 0.78, 1.55). Disposable e-cigarettes (exempt from flavor restrictions) increased to a greater extent among vapers in the United States (13.2% to 36.8%) versus Canada (7.7% to 14.2%; AOR = 2.01; 95% CI = 1.33, 3.04) and England (10.8% to 16.4%; AOR = 2.33; 95% CI = 1.52, 3.57). Puff Bar (disposable) emerged as the most popular brand in the United States. Conclusions. Usual flavors used by youth vapers in the United States were unchanged after 2020 restrictions on cartridge-based e-cigarettes. Youths used brands and devices exempt from the restrictions. (Am J Public Health. 2022;112(7):1014-1024. https://doi.org/10.2105/AJPH.2022.306780).

Changes in the Patterns and Characteristics of Youth ENDS Use over Time

Research on youth use of electronic nicotine delivery systems (ENDS) has explored the correlates of initiation and use; however, little is known about the factors that predict continued youth use of ENDS. We used an ecological momentary assessment (EMA) burst design to explore both daily variability within adolescents over a two-week observation period and variability over time two years later (2018 and 2020). The contribution of device characteristics, motivations for use, contextual factors, and community factors to daily use occasions were explored. Youth participants (n = 35) at the start of the study were past two-week nicotine vapers, 14 to 17 years old, who resided within 100 miles of Louisville, KY, and reported past two-week ENDS use. Close to a quarter of participants ceased all tobacco use two years later, suggesting that some youth, despite prior regular vaping habits, may have only been experimenting with ENDS. The regular continued use of ENDS was predicted by trying to quit using cigarettes, appealing flavors, and being in locations where cigarette use was prohibited. Except for flavors, these factors did not affect ENDS use in year one. These findings suggest that tobacco policy might target ENDS use by prohibiting all tobacco use, including ENDS, in locations where smoking is already banned.

Discussions of Flavored ENDS Sales Restrictions: Themes Related to Circumventing Policies on Reddit

OBJECTIVE

To examine conversations among JUUL users on Reddit related to restrictions on flavored ENDS and the shifting policy landscape.

METHODS

Posts and comments (n = 166,169) between May 2019 and May 2020 on the subreddit r/JUUL were scraped using pushshift.io API. Keyword filters were used to identify texts discussing flavored ENDS products (n = 33,884 texts). These were further narrowed down to texts discussing flavor policy workaround strategies (n = 7429) and N-gram analysis was performed. Finally, findings from the N-gram analysis were triangulated through qualitative review of a separate sample of texts (n = 488) from the flavor policy-related posts and comments.

RESULTS

Overall activity on the subreddit r/JUUL peaked around the time of the EVALI outbreak (September 2019) and when FDA issued guidance restricting flavored ENDS product sales (January 2020). The N-gram analysis revealed an active discussion of banned products one can "still get" or "JUUL compatible" alternatives, including specific brands, brick and mortar locations, and specific flavors. Ten dominant themes emerged from the qualitative review, with some posts containing more than one theme.

CONCLUSION

Many users turned to Reddit for information related to the shifting regulatory landscape concerning flavored ENDS. Discussions focused on both legal alternatives to banned products as well as illegal means of acquiring JUUL pods, including residual retail supply, online, and mail vendors.

Trajectories of Nicotine Use Leading to Dual and Cyclical Tobacco Product Use in Young Adults

INTRODUCTION

Young adult never-smokers who vape are at elevated risk of initiating cigarettes, while young adults who smoke often begin vaping to substitute or reduce cigarette use. Reasons underlying different use patterns of tobacco products are not well-understood.

AIMS AND METHODS

We conducted 1-on-1 qualitative interviews with young adults (N = 62) who vape in Los Angeles, California from June 2018 to June 2019. Participants were 18-25 years old (79% male; racially/ethnically diverse) and self-reported vaping ≥1x/week. We used a semi-structured interview guide and applied thematic analysis method to analyze data.

RESULTS

Young adults initiated vaping due to peer socialization and e-liquid flavor novelty. They often reported vaping (after first smoking) due to a belief that e-cigarettes are healthier, social pressure to quit smoking, and convenience of use. Participants reported smoking (after first vaping) when traveling outside of the United States where vaping products were less accessible, and cigarettes were normative. Many of the personal narratives described patterns of dual and cyclical use, which was often attributed to nicotine dependence and cost, or described as dependent upon the current environment (eg, at a party).

CONCLUSIONS

The current study characterizes nicotine use trajectories and reasons why young adults vape, and smoke cigarettes. Dual and cyclical use of both e-cigarettes and cigarettes was common; this pattern of use should be considered in policy and prevention work to address nicotine dependence among young people.

IMPLICATIONS

We display findings from the current study in a model depicting common trajectories of nicotine use, along with reasons for initiation, transitions between products, and dual/cyclical e-cigarette and combustible cigarette use.

Dissonance in Young Adult Cigarillo Users' Categorization of Concept Flavored and Unflavored Products

This study asks young adult cigarillo users to categorize their preferred flavor in order to examine user consensus and potential methodological and regulatory implications of flavor name-based categorization systems. Young adult (21–28 years) cigarillo users (n = 426) named and categorized their favorite cigarillo flavor into one of seven categories: Fruit, Sweet and Candy, Mint, Alcohol, Menthol, Tobacco, and Other. Flavor responses were coded as characterizing (ex: Grape, Wine) or concept (ex: Jazz, Diamond) flavors. Variation within and between categories was assessed, including the presence of concept flavors and the placement of flavors in multiple categories. Of the 66 unique flavor names provided, participants placed 20 (30.1%) in more than one flavor category. Most of the Tobacco (76.9%) and Other (69.2%) flavor names appeared in multiple categories. The majority of flavor names in the Tobacco (69.2%) and Other (61.5%) categories were concept flavors. Concept flavors were placed in multiple categories (45.0%) twice as often as characterizing flavors (23.9%). This study has identified dissonance among cigarillo users’ flavor categorizations, particularly for concept flavored and unflavored products. Flavor names may obscure how and whether a product is flavored. Research on and regulation of flavored tobacco products should classify products by flavor additives rather than by name alone.

Youth use of e-liquid flavours-a systematic review exploring patterns of use of e-liquid flavours and associations with continued vaping, tobacco smoking uptake or cessation

BACKGROUND AND AIMS

There is concern that young people may be attracted to e-liquid flavours, prompting long-term vaping in naive users and potentially subsequent tobacco smoking. We aimed to review the use of e-liquid flavours by young people and describe associations with uptake or cessation of both regular vaping and tobacco smoking, adverse effects and subjective experiences.

DESIGN

Systematic review, including interventional, observational and qualitative studies reporting on the use of e-cigarette flavours by young people (aged < 18 years).

SETTING

Studies published in English language from any country or cultural setting.

PARTICIPANTS

Young people and their carers (aged < 18 years).

MEASUREMENTS

A meta-analysis was not possible due to substantial heterogeneity, inconsistency in reporting of flavour categorizations and non-interventional study designs; thus, we narratively report findings.

FINDINGS

In total, 58 studies were included. The quality of the evidence was extremely low. Most (n = 39) studies were cross-sectional survey designs. In total, 11 longitudinal cohort studies assessed trajectories; eight qualitative studies reported on user experiences. Studies reported views and experiences of a total of 512 874 young people. Both cross-sectional and longitudinal studies suggested that flavours are important for initiation and continuation of vaping. Qualitative evidence shows interest and enjoyment in flavours. There was judged to be insufficient evidence that use of e-liquid flavours specifically is associated with uptake of smoking. No studies found clear associations between flavours and cessation in this population. We found no included reports of adverse effects of flavours.

CONCLUSIONS

Flavours may be an important motivator for e-cigarette uptake, but the role of flavours in tobacco smoking uptake or cessation is unclear. The quality of the evidence on use of e-cigarette flavours by young people is low overall.

Toxicological Assessment of Flavor Ingredients in E-Vapor Products

Many flavor ingredients are often used in potentially reduced-risk tobacco products (such as e-vapor products). Although most are “generally recognized as safe (GRAS)” when used in food, there is limited information available on their long-term health effects when delivered by inhalation. While obtaining route-of-exposure-specific toxicological data on flavor ingredients is critical to product evaluation, the large number of individual flavor ingredients available and their potential combinations render classical toxicological assessment approaches impractical, as they may require years of preclinical investigations and thousands of laboratory animals. Therefore, we propose a pragmatic approach in which flavor ingredients are initially assigned to groups of structurally related compounds (Flavor Groups), from which flavor group representatives (FGR) are then selected and tested individually and as a mixture in vitro and in vivo. The premise is that structurally related compounds would have comparable metabolic and biological activity and that the data generated using FGRs could support the toxicological assessment of other structurally related flavor ingredients of their respective Flavor Groups. This approach is explained in a step-wise manner and exemplified by a case study, along with its strengths, limitations as well as recommendations for further confirmatory testing. Once completed, this FGR approach could significantly reduce the time and resources required for filling the data gap in understanding the health risks of many flavor ingredients while also minimizing the need for laboratory animals.

Impulsivity-Related Personality Traits as Predictors of E-Cigarette Use among Young Adults over Time

Introduction: There has been rising concern about e-cigarette usage among teenagers and young adults. As knowledge about the adverse health effects of e-cigarettes accumulates, it is critical to identify factors that may increase risk of vaping initiation and frequency of use. One potential risk factor known to increase risk for other substance use is impulsivity. This study tested the hypothesis that impulsivity prospectively predicts vaping over time. Methods: Active e-cigarette users (n = 137; 51.8% male; Mean age 20 years at baseline) completed 8 waves of assessment over 21 months (2017-2020). The S-UPPS-P impulse behavior scale was used at baseline to measure impulsivity, and frequency of e-cigarette, cigarette, marijuana and alcohol use was calculated at each wave thereafter. Results: Vaping frequency declined over time [Incidence Rate Ratio (IRR) = 0.92]. There were significant, stable, positive associations between e-cigarette use and lack of premeditation (IRR = 1.06) and sensation seeking (IRR = 1.09). Vaping frequency was inversely associated with negative urgency (IRR = 0.95). Positive urgency and lack of perseverance were not associated with frequency of vaping. Conclusion: These findings suggest that young adults who have higher impulsivity of certain types may use e-cigarettes more frequently. Thus, vaping interventions for young adults should address these factors to ensure the greatest impact on public health.