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

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.

Flavored waterpipe tobacco preferences, perceptions, and use in pregnant women: A latent factor mapping approach

Waterpipe tobacco (WPT) use is increasingly common in young adults including pregnant and reproductive-age women. Sweet flavors contribute to the appeal of WPT and are a promising regulatory target. The present study utilized correspondence analysis of contingency tables, a latent factor mapping technique, to investigate preferences and perceptions of WPT flavors in a sample of racially/ethnically diverse, low-income pregnant women. One hundred pregnant women (mean age = 26 years, 65% racial/ethnic minorities) completed a detailed interview regarding their use, preferences, and perceptions of WPT flavors. Eighty-three percent of participants reported lifetime WPT use; 11% reported prenatal WPT use. Pregnant women reported greatest use of and stronger preferences for sweet (fruit, candy, alcohol) and menthol/mint flavors, and weaker preferences for tobacco flavored WPT. Latent factor mapping revealed clustering of preferred sweet (fruit, candy, alcohol) and menthol/mint flavors versus tobacco flavors, with pungent flavors (coffee, chocolate, spice) clustering between sweet and tobacco flavors. Preferences for sweet and menthol/mint flavors distinguished pregnant women who reported lifetime WPT versus no lifetime WPT use, and prenatal WPT use versus no prenatal WPT use. Harm perceptions did not vary by flavor. Regulations to restrict the availability of WPT flavors may reduce the appeal and use of WPT, especially among pregnant women.

Responses to potential nicotine vaping product flavor restrictions among regular vapers using non-tobacco flavors: Findings from the 2020 ITC Smoking and Vaping Survey in Canada, England and the United States

INTRODUCTION

Some jurisdictions have implemented nicotine vaping product (NVP) flavor restrictions because of concerns about rising adolescent use. However, little is known how these restrictions may impact adult vapers. This study describes the level of support and predictive behavioral responses to a hypothetical NVP ban on non-tobacco flavors among regular adult vapers who only use flavors that would be banned.

METHODS

Data came from 851 regular vapers (all current or ex-smokers) participating in the 2020 ITC Four Country Smoking and Vaping Survey in Canada, England, and the United States (US). A random sample of respondents in each country received and completed the questions about flavor bans: (1) do you support or oppose a ban on all non-tobacco flavors; and (2) what would you do if all flavors were banned, with the exception of tobacco in the US, and tobacco and menthol in Canada and England. Those who used tobacco-flavored or unflavored NVPs were excluded from all analyses, and additionally, vapers of menthol flavor in Canada and England were excluded from Aim 2.

RESULTS

Overall, 53.6% of vapers were strongly opposed to flavor bans, 28.2% were opposed, 9.3% were in support, 3.6% were in strong support, and 5.2% did not know. Predicted behavioral responses were: 28.8% would continue vaping an available flavor, 28.3% would find a way to get their banned flavor(s), 17.1% would stop vaping and smoke instead, 12.9% said that they would stop vaping and not smoke, and 12.9% do not know what they would do. Responses to a potential flavor ban largely varied by smoking and vaping status, and by the level of support of a flavor restriction policy.

CONCLUSIONS

At this time, it is not clear what net population-level consequences would occur if non-tobacco flavored NVPs were prohibited. While a majority of vapers in this study opposed this policy, and many vapers would not be willing to switch to available flavors, there was considerable variability in predicted behavioral responses.

Association of preferred flavorings and device type with box or pack purchase behavior of electronic nicotine delivery systems in the United States

This study examined the associations of preferred flavorings and device type of ENDS with box or pack purchase behavior. We analyzed current adult ENDS users in the United States who reported purchase of their own ENDS. Logistic regression revealed an increased likelihood of box/pack purchase behavior among users of menthol or mint-flavored ENDS, disposable, pod-based devices, and those who purchase ENDS from the Internet. A moderation analysis showed that the magnitude of the association between menthol or mint-flavored ENDS use and box/pack purchase was stronger among disposable and pod-based device users compared to tank or mods (customizable devices) users. In a subsequent stratified analysis menthol or mint flavor users were more likely than non-flavor users to engage in box/pack purchase among disposable and pod-based device users, but not among tank or mods users. Regulating flavors and maximum unit sale quantities of ENDS by device could thwart ENDS box/pack purchase behavior.

E-Cigarette Toxicology

Since the spread of tobacco from the Americas hundreds of years ago, tobacco cigarettes and, more recently, alternative tobacco products have become global products of nicotine addiction. Within the evolving alternative tobacco product space, electronic cigarette (e-cigarette) vaping has surpassed conventional cigarette smoking among adolescents and young adults in the United States and beyond. This review describes the experimental and clinical evidence of e-cigarette toxicity and deleterious health effects. Adverse health effects related to e-cigarette aerosols are influenced by several factors, including e-liquid components, physical device factors, chemical changes related to heating, and health of the e-cigarette user (e.g., asthmatic). Federal, state, and local regulations have attempted to govern e-cigarette flavors, manufacturing, distribution, and availability, particularly to underaged youths. However, the evolving e-cigarette landscape continues to impede timely toxicological studies and hinder progress made toward our understanding of the long-term health consequence of e-cigarettes.

Animal Models to Investigate the Impact of Flavors on Nicotine Addiction and Dependence

BACKGROUND

Tobacco use in humans is a long-standing public health concern. Flavors are common additives in tobacco and alternative tobacco products, added to mask nicotine's harsh orosensory effects and increase the appeal of these products. Animal models are integral for investigating nicotine use and addiction and are helpful for understanding the effects of flavor additives on the use of nicotine delivery products.

OBJECTIVE

This review focuses on preclinical models to evaluate the contribution of flavor additives to nicotine addiction.

MATERIALS AND METHODS

An electronic literature search was conducted by authors up to May 2022. Original articles were selected.

RESULTS

The behavioral models of rodents described here capture multiple dimensions of human flavored nicotine use behaviors, including advantages and disadvantages.

CONCLUSION

The consensus of the literature search was that human research on nicotine use behavior has not caught up with fast-changing product innovations, marketing practices, and federal regulations. Animal models are therefore needed to investigate mechanisms underlying nicotine use and addiction. This review provides a comprehensive overvie.

Fundamentals of vaping-associated pulmonary injury leading to severe respiratory distress

Vaping of flavored liquids has been touted as safe alternative to traditional cigarette smoking with decreased health risks. The popularity of vaping has dramatically increased over the last decade, particularly among teenagers who incorporate vaping into their daily life as a social activity. Despite widespread and increasing adoption of vaping among young adults, there is little information on long-term consequences of vaping and potential health risks. This study demonstrates vaping-induced pulmonary injury using commercial JUUL pens with flavored vape juice using an inhalation exposure murine model. Profound pathological changes to upper airway, lung tissue architecture, and cellular structure are evident within 9 wk of exposure. Marked histologic changes include increased parenchyma tissue density, cellular infiltrates proximal to airway passages, alveolar rarefaction, increased collagen deposition, and bronchial thickening with elastin fiber disruption. Transcriptional reprogramming includes significant changes to gene families coding for xenobiotic response, glycerolipid metabolic processes, and oxidative stress. Cardiac systemic output is moderately but significantly impaired with pulmonary side ventricular chamber enlargement. This vaping-induced pulmonary injury model demonstrates mechanistic underpinnings of vaping-related pathologic injury.

#FlavorsSaveLives: An Analysis of Twitter Posts Opposing Flavored E-cigarette Bans

BACKGROUND

Starting in 2019 policies restricting the availability of flavored e-cigarette products were proposed or implemented in the United States to curb vaping by youth. People took to Twitter to voice their opposition, referencing the phrase "Flavors Save Lives." This study documented the emerging themes pertaining to "Flavors Saves Lives" over a 12-month period.

METHODS

The study period was from May 1, 2019, to May 1, 2020. A stratified sampling procedure supplied 2500 tweets for analysis. Posts were classified by one or more of the following themes: (1) Political Referendum; (2) Institutional Distrust; (3) Individual Rights; (4) Misinformation; (5) THC Vaping is the Real Problem; (6) Smoking Cessation; (7) Adult Use; and (8) Not a Bot. The temporal pattern of tweets over the year was examined.

RESULTS

Political Referendum (76.5%) and Institutional Distrust (31.3%) were the most prominent themes, followed by Not a Bot (11.0%), Individual Rights (10.4%), Adult Use (8.0%), Smoking Cessation (6.6%), Misinformation (5.9%), and THC Vaping is the Real Problem (3.5%). Total tweet frequencies increased in September 2019 and peaked in November 2019 before returning to relatively low numbers. Political Referendum and Institutional Distrust were consistently the most prevalent themes over time.

CONCLUSION

Twitter posts with the phrase "Flavors Save Lives" commonly discussed voting against political incumbents and mentioned distrust of government representatives. Findings demonstrated the possibility of near real-time Twitter monitoring of public opposition to flavor bans. These data may be valuable for designing tobacco control information campaigns in the future.

IMPLICATIONS

(a) Starting in 2019 policies restricting the availability of flavored e-cigarette products were proposed or implemented in the United States to curb vaping by youth. (b) This study content analyzed Twitter posts with the phrase "Flavors Save Lives" from a 12-month period to understand opposition to flavor restrictions. (c) Twitter posts commonly discussed voting against political incumbents and mentioned distrust of government representatives. (d) Findings demonstrated the possibility of near real-time Twitter monitoring of public opposition to flavor bans, and contribute to a more comprehensive assessment of different sub-population's responses to current and proposed tobacco control information policies.

Twitter Surveillance at the Intersection of the Triangulum

INTRODUCTION

A holistic public health surveillance approach can help capture the public's tobacco and marijuana-related attitudes and behaviors. Using publicly available data from Twitter, this is one of the first studies to describe key topics of discussions related to each intersection (e-cigarette, combustible tobacco, and marijuana) of the Triangulum framework.

METHOD

Twitter posts (n=999,447) containing marijuana, e-cigarette and combustible tobacco terms were collected from January 1, 2018, to December 23, 2019. Posts to Twitter with co-occurring mentions of keywords associated with the Triangulum were defined as an intersection (e-cigarettes and combustible tobacco, combustible tobacco and marijuana, e-cigarettes and marijuana, and marijuana, e-cigarettes and combustible tobacco). Text classifiers and unsupervised machine learning was used to identify predominant topics in posts.

RESULTS

Product Features and Cartridges were commonly referenced at the intersection of e-cigarette and marijuana-related conversations. Blunts and Cigars and Drugs and Alcohol were commonly referenced at the intersection of combustible tobacco and marijuana-related discussions. Flavors and Health Risks were discussed at the intersection of e-cigarette and combustible-related conversations, while discussions about Illicit products and Health risks were key topics of discussion when e-cigarettes, combustible tobacco, and marijuana were referenced all together in a single post.

CONCLUSION

By examining intersections of marijuana and tobacco products, this study offers inputs for designing comprehensive FDA regulations including regulating product features associated with appeal, improving enforcement to curb sales of illicit products, and informing the FDA's product review and standards procedures for tobacco products that can be used with marijuana.

IMPLICATIONS

This study is the first to leverage the Triangulum framework and Twitter data to describe key topics of discussions at the intersection of e-cigarette, combustible tobacco, and marijuana. Real-time health communication interventions can identify Twitter users posting in the context of e-cigarettes, combustible tobacco, and marijuana by automated methods and deliver tailored messages. This study also demonstrates the utility of Twitter data for surveillance of complex and evolving health behaviors.

Choice and Variety-Seeking of E-liquids and Flavor Categories by New Zealand Smokers Using an Electronic Cigarette: A Longitudinal Study

BACKGROUND

Little is currently known about how e-liquid flavor use evolves among electronic cigarette users. We describe patterns of e-liquid and flavor category use, and variety-seeking, among New Zealand adult smokers attempting to transition from smoking to e-cigarettes.

METHODS

Data were collected in 2018-19, using a longitudinal design comprising up to five in-depth interviews over a 12-20 week period. Participants (n = 32) were current smokers aged ≥18 years, who were not currently using an e-cigarette once a week or more often, and were willing to use an e-cigarette in an attempt to stop smoking. We purchased participants a starter e-cigarette of their choice; they supplied their own e-liquids throughout the study. We extracted e-liquid use data from the verbatim interview transcripts, categorized these into flavor categories, and then explored these data for the whole sample, and by flavor category purchased at intake.

RESULTS

Most participants (n = 12) selected a tobacco flavored e-liquid at intake; fruit (n = 7), mint/menthol (n = 6), and dessert/sweets and non-alcoholic beverage (both n = 5) were also popular. Most participants were still using their initially chosen flavor category at study exit, however, many described variety-seeking behaviors, which typically occurred during the first 12 weeks of enrolment.

CONCLUSION

Most participants did not follow a straightforward e-liquid or flavor category pathway. Evidence of a variety-seeking continuum, typically occurring within the first 12 weeks, suggests possible opportunities at specialist e-cigarette stores to couple e-liquid purchasing occasions with cessation advice.

IMPLICATIONS

Variety-seeking behavior was common and typically reported within the first 12 weeks of participants' e-cigarette-assisted attempt to transition away from smoking. Policies allowing diverse e-liquid flavors at specialist stores only could support users' variety-seeking and potentially create opportunities to couple e-liquid purchasing occasions with cessation advice during the first months of a transition attempt.

Changes in Flavor Preference in a Cohort of Long-Term Electronic Cigarette Users

Rationale: The use of electronic cigarettes (e-cigarettes) has rapidly increased in the United States, and thousands of e-cigarette flavors are available. However, there remains a dearth of evidence on e-cigarette flavor use patterns among older e-cigarette users.

Objectives: This longitudinal study examined changes in flavor use patterns in long-term e-cigarette users, assessed self-reported adverse reactions, and evaluated users’ anticipated reactions to possible U.S. Food and Drug Administration e-cigarette flavor regulatory scenarios.

Methods: The study population was 383 adult participants who completed two online e-cigarette surveys in 2012–2014 (baseline survey) and in 2017–2019 (follow-up survey). In both surveys, participants were asked, “Thinking about your preferred liquid, what is the name of this liquid flavor?” and to list all flavors used in the past 30 days. Flavor preference was classified using the Penn State Three-Step Flavor Classification method. Participants reported adverse events (open-ended description) with the associated flavor. Regulatory scenarios were presented, and participants selected perceived actions from among a list of 15 options.

Results: Participants’ age averaged 44 ± 12 years; 86% were exclusive e-cigarette users, and 13% reported “poly-use” (i.e., e-cigarette and other tobacco product use). E-cigarette flavor preference migration occurred in all demographic groups: only 36–44% maintained a preference for their original flavor. Preference for tobacco and menthol or mint decreased over time (40% baseline vs. 22% follow-up); preference for fruit remained stable (23% baseline and follow-up), but chocolate/candy or other sweets preference significantly increased (16% baseline vs. 29% follow-up), and other flavors increased slightly. Migration to sweet flavors was more noticeable in younger adults (18–45 yr); exclusive e-cigarette users preferred sweet flavors more commonly than poly-users did (31% vs. 19%). Flavor-associated adverse reactions, mainly respiratory irritations, were reported by 26 (6.9%) participants. Nearly 50% of the participants reported that they would “find a way” to buy their preferred flavor or add flavoring agents themselves if nontobacco flavors were banned.

Conclusions: Flavor migration toward sweet flavors occurred in long-term e-cigarette users, a trend most pronounced in younger and exclusive e-cigarette users. The anticipated maintenance of access to flavors despite regulation suggests an element of e-cigarette–related dependence that requires further evaluation. This information could help clinicians understand the health impacts of e-cigarette flavors, develop appropriate strategies for smoking cessation, and inform the U.S. Food and Drug Administration to plan future regulation of e-cigarette flavors.

Vaping epidemic in US teens: problem and solutions

PURPOSE OF REVIEW

Over the last decade, vaping has emerged into an epidemic of alarming proportions among US teens. This review evaluates the factors leading to the rise of vaping, reasons for its striking popularity among US teens, health consequences of vaping, and measures to mitigate the vaping epidemic.

RECENT FINDINGS

Contemporary research highlights the continued rise of vaping amongst US teens and explains the reasons for its popularity, such as the variety of devices, a wide range of available flavors, youth-targeted advertisements, and lack of awareness of adverse consequences from vaping. This publication highlights current research findings of health consequences of vaping, including a discussion of EVALI (e-cigarette or vaping product use-associated lung injury) and provides an update on strategies to curtail the vaping epidemic.

SUMMARY

Vaping has risen to epidemic proportions amongst US teens. This poses a clear and present danger to teens' health with adverse effects ranging from acute lung injury to long-term addiction. This article summarizes key research findings that explain the reasons for the epidemic, health consequences of vaping, and provides an overview of efforts to mitigate the vaping threat to US teens.

A machine learning approach to identify correlates of current e-cigarette use in Canada

Aim: Popularity of electronic cigarettes (i.e. e-cigarettes) is soaring in Canada. Understanding person-level correlates of current e-cigarette use (vaping) is crucial to guide tobacco policy, but prior studies have not fully identified these correlates due to model overfitting caused by multicollinearity. This study addressed this issue by using classification tree, a machine learning algorithm. Methods: This population-based cross-sectional study used the Canadian Tobacco, Alcohol, and Drugs Survey (CTADS) from 2017 that targeted residents aged 15 or older. Forty-six person-level characteristics were first screened in a logistic mixed-effects regression procedure for their strength in predicting vaper type (current vs. former vaper) among people who reported to have ever vaped. A 9:1 ratio was used to randomly split the data into a training set and a validation set. A classification tree model was developed using the cross-validation method on the training set using the selected predictors and assessed on the validation set using sensitivity, specificity and accuracy. Results: Of the 3,059 people with an experience of vaping, the average age was 24.4 years (standard deviation = 11.0), with 41.9% of them being female and 8.5% of them being aboriginal. There were 556 (18.2%) current vapers. The classification tree model performed relatively well and suggested attraction to e-cigarette flavors was the most important correlate of current vaping, followed by young age (< 18) and believing vaping to be less harmful to oneself than cigarette smoking. Conclusions: People who vape due to flavors are associated with very high risk of becoming current vapers. The findings of this study provide evidence that supports the ongoing ban on flavored vaping products in the US and suggests a similar regulatory intervention may be effective in Canada.

The Association of E-cigarette Flavors With Satisfaction, Enjoyment, and Trying to Quit or Stay Abstinent From Smoking Among Regular Adult Vapers From Canada and the United States: Findings From the 2018 ITC Four Country Smoking and Vaping Survey

Aims

This study examined whether nontobacco flavors are more commonly used by vapers (e-cigarette users) compared with tobacco flavor, described which flavors are most popular, and tested whether flavors are associated with: vaping satisfaction relative to smoking, level of enjoyment with vaping, reasons for using e-cigarettes, and making an attempt to quit smoking by smokers.

Methods

This cross-sectional study included 1603 adults from Canada and the United States who vaped at least weekly, and were either current smokers (concurrent users) or former smokers (exclusive vapers). Respondents were categorized into one of seven flavors they used most in the last month: tobacco, tobacco–menthol, unflavored, or one of the nontobacco flavors: menthol/mint, fruit, candy, or “other” (eg, coffee).

Results

Vapers use a wide range of flavors, with 63.1% using a nontobacco flavor. The most common flavor categories were fruit (29.4%) and tobacco (28.7%), followed by mint/menthol (14.4%) and candy (13.5%). Vapers using candy (41.0%, p < .0001) or fruit flavors (26.0%, p = .01) found vaping more satisfying (compared with smoking) than vapers using tobacco flavor (15.5%) and rated vaping as very/extremely enjoyable (fruit: 50.9%; candy: 60.9%) than those using tobacco flavor (39.4%). Among concurrent users, those using fruit (74.6%, p = .04) or candy flavors (81.1%, p = .003) were more likely than tobacco flavor users (63.5%) to vape in order to quit smoking. Flavor category was not associated with the likelihood of a quit attempt (p = .46). Among exclusive vapers, tobacco and nontobacco flavors were popular; however, those using tobacco (99.0%) were more likely than those using candy (72.8%, p = .002) or unflavored (42.5%, p = .005) to vape in order to stay quit.

Conclusions

A majority of regular vapers in Canada and the US use nontobacco flavors. Greater satisfaction and enjoyment with vaping are higher among fruit and candy flavor users. While it does not appear that certain flavors are associated with a greater propensity to attempt to quit smoking among concurrent users, nontobacco flavors are popular among former smokers who are exclusively vaping. Future research should determine the likely impact of flavor bans on those who are vaping to quit smoking or to stay quit.

Implications

Recent concerns about the attractiveness of e-cigarette flavors among youth have resulted in flavor restrictions in some jurisdictions of the United States and Canada. However, little is known about the possible consequences for current and former smokers if they no longer have access to their preferred flavors. This study shows that a variety of nontobacco flavors, especially fruit, are popular among adult vapers, particularly among those who have quit smoking and are now exclusively vaping. Limiting access to flavors may therefore reduce the appeal of e-cigarettes among adults who are trying to quit smoking or stay quit.

Vaping Restrictions: Is Priority to the Young Justified?

The vast majority of smokers become dependent on nicotine in youth. Preventing dependence has therefore been crucial to the recent decline in youth smoking. The advent of vaping creates an opportunity for harm reduction to existing smokers (mostly adults) but simultaneously also undermines prevention efforts by becoming a new vehicle for young people to become dependent on nicotine, creating an ethical dilemma. Restrictions to access to some vaping products enacted in response to the increase in vaping among youth observed in the United States since 2018 have arguably prioritized prevention of new cases of dependence-protecting the young-over harm reduction to already dependent adults. Can this prioritization of the young be justified? This article surveys the main bioethical arguments for prioritizing giving health benefits to the young and finds that none can justify prioritizing dependence prevention over harm reduction: any reasons for prioritizing the current cohort of young people at risk from vaping will equally apply to current adult smokers, who are overwhelmingly likely to have become nicotine-dependent in their own youth. Public health authorities' current tendency to prioritize the young, therefore, does not seem to be ethically justified.

IMPLICATIONS

This article argues that commonsense reasons for prioritizing the young do not apply to the ethical dilemma surrounding restricting access to vaping products.

Simultaneous Use of Alcohol and Electronic Nicotine Delivery Systems among College Students: Vaping History, Motivations for Use, and Outcome Expectancies

Introduction: Simultaneous polydrug use of electronic nicotine delivery systems (ENDS) and alcohol among college students is not well understood despite high rates of vaping and alcohol use among this population. The current study examined rates of simultaneous use and compared demographic characteristics, vaping history, motivations for initiating use, and outcome expectancies based on polydrug use status. Methods: An online and paper-and pencil questionnaire was administered to undergraduate students at a university in the northeast of the U.S. Purposive sampling strategies were used and a raffle was offered to incentivize participation. Results: Simultaneous polydrug use was prevalent in the sample of 670 college students, with 55.6% reporting simultaneous and non-simultaneous use, 34.0% reporting simultaneous use only, and 10.4% reporting non-simultaneous use only. An examination of differences based on polydrug use status indicated that students who reported simultaneous and non-simultaneous use were more likely to be males, report vaping daily, and endorse a wide range of motivations for use. Students who engaged in simultaneous use only were more likely to be females, indicate a social contextual-related motivation for initiating use, and had higher scores on appetite control, emotion regulation, and taste sensation outcome expectancies. Students who engaged in non-simultaneous use only were more likely to be nonwhite students and report the lowest expectation of health risks. Conclusions: The findings reveal differences based on simultaneous polydrug use status that can be informative in the development of contextually relevant prevention programming. Future research is needed to further explore simultaneous use of ENDS and alcohol.

Flavor-Toxicant Correlation in E-cigarettes: A Meta-Analysis

Flavors in electronic cigarette (ECIG) liquids may increase ECIG aerosol toxicity via intact distillation or chemical transformation. For this report, we performed a meta-analysis of the literature to categorize the compounds found in flavored ECIG liquids into a few chemical classes and to predict their possible chemical transformations upon ECIG liquid aerosolization. This analysis allowed us to propose specific correlations between flavoring chemicals and aerosol toxicants. A literature search was conducted in November 2019 using PubMed. Keywords included terms related to ECIGs and flavors. Studies were included if they reported chemical ingredients of flavored liquids and clearly stated the commercial names of these liquids. The obtained data were visualized on a network diagram to show the common chemical compounds identified in flavored ECIG liquids and categorize them into different chemical classes. The systematic literature review included a total of 11 articles. Analysis of the data reported gave a total of 189 flavored liquids and 173 distinct chemical compounds that were categorized into 22 chemical classes according to their functional groups. The subsequent prediction of chemical transformations of these functional groups highlighted the possible correlation of flavor compounds to aerosol toxicants.

Associations between reasons for vaping and current vaping and smoking status: Evidence from a UK based cohort

BACKGROUND

This study aimed to discover which young adults vape, the reasons given for vaping, and which reasons for vaping are associated with continued vaping/smoking.

METHODS

In a UK cohort of 3,994 young adults, we explored the association of retrospectively-recalled reasons for vaping by 23 years (collected between 2015 and 2016) with vaping/smoking status at 24 years (collected between 2016 and 2017). Using logistic regression, we assessed the association with vaping behaviour among ever vapers who had ever smoked (n = 668), and with smoking behaviour among individuals who regularly smoked prior to vaping (n = 412).

RESULTS

Vaping to quit smoking was associated with higher likelihood of vaping (odds ratio [OR] = 3.51, 95 % confidence interval [95 % CI] = 2.29-5.38), but lower likelihood of smoking at 24 years (OR = 0.50, 95 %CI = 0.32 to 0.78). Vaping to cut down smoking was associated with higher likelihood of vaping (OR = 2.90, 95 % CI = 1.87-4.50) and smoking at 24 years (OR = 1.62, 95 % CI = 1.02-2.58). Vaping out of curiosity was associated with lower likelihood of vaping at 24 years (OR = 0.41, 95 %CI = 0.26 to 0.63) but higher likelihood of smoking at 24 years (OR = 1.66, 95 % CI = 1.04-2.65).

CONCLUSIONS

Intention to quit appears important for young adults to stop smoking using e-cigarettes. Public health strategies that encourage vaping specifically for smoking cessation may encourage quitting among young adults.

E-cigarettes: How can they help smokers quit without addicting a new generation?

The dramatic increase in youth use of electronic nicotine delivery systems (ENDS; e.g., e-cigarettes) in the United States has focused regulatory efforts to address this concern while still encouraging smokers to switch completely to lower risk products or quit all tobacco product use. Increases in the minimum age for purchase of all tobacco products and changes in enforcement policy for ENDS have been recently enacted in an effort to address the youth vaping epidemic. Since all ENDS marketed after February 15, 2007 will be required to meet the "appropriate for the protection of public health" standard for marketing authorization of new products, ENDS manufacturers will have to demonstrate, in part, that their products help lessen the adverse impact on youth use. Some, such as disallowing flavors other than tobacco or menthol or limiting nicotine delivery, may help reduce youth use but could also inhibit smokers from quitting smoking. Other approaches, including reducing the high-tech appearance and discreteness of ENDS, discontinuing use of coupons and two-for-one type price incentives for ENDS, limiting retail sales of these products to adult-only facilities, and incorporating technological innovations such as biometrics or geofencing into ENDS, may help manufacturers demonstrate that marketing of their products would help reduce youth use of ENDS and lessen the epidemic, while still assuring adult smokers have access to products that encourage discontinuing combusted product use.

Cell-specific toxicity of short-term JUUL aerosol exposure to human bronchial epithelial cells and murine macrophages exposed at the air-liquid interface

Backgroud

JUUL, an electronic nicotine delivery system (ENDS), which first appeared on the US market in 2015, controled more than 75% of the US ENDS sales in 2018. JUUL-type devices are currently the most commonly used form of ENDS among youth in the US. In contrast to free-base nicotine contained in cigarettes and other ENDS, JUUL contains high levels of nicotine salt (35 or 59 mg/mL), whose cellular and molecular effects on lung cells are largely unknown. In the present study, we evaluated the in vitro toxicity of JUUL crème brûlée-flavored aerosols on 2 types of human bronchial epithelial cell lines (BEAS-2B, H292) and a murine macrophage cell line (RAW 264.7).

Methods

Human lung epithelial cells and murine macrophages were exposed to JUUL crème brûlée-flavored aerosols at the air–liquid interface (ALI) for 1-h followed by a 24-h recovery period. Membrane integrity, cytotoxicity, extracellular release of nitrogen species and reactive oxygen species, cellular morphology and gene expression were assessed.

Results

Crème brûlée-flavored aerosol contained elevated concentrations of benzoic acid (86.9 μg/puff), a well-established respiratory irritant. In BEAS-2B cells, crème brûlée-flavored aerosol decreased cell viability (≥ 50%) and increased nitric oxide (NO) production (≥ 30%), as well as iNOS gene expression. Crème brûlée-flavored aerosol did not affect the viability of either H292 cells or RAW macrophages, but increased the production of reactive oxygen species (ROS) by ≥ 20% in both cell types. While crème brûlée-flavored aerosol did not alter NO levels in H292 cells, RAW macrophages exposed to crème brûlée-flavored aerosol displayed decreased NO (≥ 50%) and down-regulation of the iNOS gene, possibly due to increased ROS. Additionally, crème brûlée-flavored aerosol dysregulated the expression of several genes related to biotransformation, inflammation and airway remodeling, including CYP1A1, IL-6, and MMP12 in all 3 cell lines.

Conclusion

Our results indicate that crème brûlée-flavored aerosol causes cell-specific toxicity to lung cells. This study contributes to providing scientific evidence towards regulation of nicotine salt-based products.

'I Think Smoking's the Same, but the Toys Have Changed.' Understanding Facilitators of E-Cigarette Use among Air Force Personnel

BACKGROUND

The military has stringent anti-tobacco regulations for new recruits. While most tobacco products have declined in recent years, e-cigarette use has tripled among this population. However, little is known about the factors facilitating this inverse relationship.

OBJECTIVES

Examine the facilitators of e-cigarette use during a high risk period following initial enlistment among young adults.

METHODS

Focus groups were conducted with Airmen, Military Training Leaders (MTLs) and Technical Training Instructors (TTIs) to qualitatively explore unique characteristics of e-cigarettes leading to use in Technical Training.

RESULTS

The most commonly used tobacco product across participants was cigarettes (42.7%), followed by e-cigarettes (28.0%) and smokeless tobacco (22.6%). Almost a third (28.7%) of participants reported using more than one tobacco product. E-cigarette use was much more common among Airmen (76.1%), compared to MTLs (10.9%) and TTIs (13.0%).Four main facilitators around e-cigarette use were identified including: 1) There is no reason not to use e-cigarettes; 2) Using e-cigarettes helps with emotion management; 3) Vaping is a way of fitting in; and 4) Existing tobacco control policies don't work for vaping. E-cigarettes were not perceived as harmful to self and others, which could explain why Airmen were much less likely to adhere to existing tobacco control regulations. Subversion was viewed as the healthy option compared to utilizing designated tobacco use areas due to the potential exposure to traditional tobacco smoke. This coupled with a lack of understanding about e-cigarette regulations and difficulties with enforcement, promoted use among this young adult population.

CONCLUSION

Findings suggest that e-cigarettes are used for similar reasons as traditional tobacco products, but their unique ability to be concealed promotes their widespread use and circumvents existing tobacco control policies. In order to see reductions in use, environmental policies may need to be paired with behavioral interventions at the personal and interpersonal level.

Electronic cigarette exposure disrupts blood-brain barrier integrity and promotes neuroinflammation

Electronic cigarette (e-cigarette) use has grown substantially since inception, particularly among adolescents and combustible tobacco users. Several cigarette smoke constituents with known neurovascular effect are present in e-cigarette liquids or formed during the vapor generation. The present study establishes inhaled models of cigarette and e-cigarette use with normalized nicotine delivery, then characterizes the impact on blood-brain barrier (BBB) function. Sequencing of microvessel RNA following exposure revealed downregulation of several genes with critical roles in BBB function. Reduced protein expression of Occludin and Glut1 is also observed at the tight junction in all groups following exposure. Pro-inflammatory changes in leukocyte-endothelial cell interaction are also noted, and mice exposed to nicotine-free e-cigarettes have impaired novel object recognition performance. On this basis, it is concluded that long term e-cigarette use may adversely impact neurovascular health. The observed effects are noted to be partly independent of nicotine content and nicotine may even serve to moderate the effects of non-nicotinic components on the blood-brain barrier.

World vaping update

PURPOSE OF REVIEW

Although death and injury related to e-cigarette use and vaping products has decreased since the peak in 2019, concern over the popularity of electronic nicotine delivery systems (ENDS - a term which includes vape pens, electronic or e-cigarettes, and products that produce vapor for inhaling rather than combusting to produce smoke) continues. ENDS are used as an aid to quit smoking and for harm reduction.

RECENT FINDINGS

This review covers peer-reviewed literature from January 2019 through February 2020 on vaping (the process of using ENDS). Prevalence, risk factors for use, and health risks and benefits from use predominated. Policy articles, commentaries and editorials were excluded from review. E-cigarette or vaping product use-associated lung injury (EVALI)-related injury and death were in the news and literature this year. Because most EVALI-related injury and death occurred among young people who had vaped tetrahydrocannabinol (THC), data from the Healthy Minds (United States) study are reviewed to consider variation in risk factors for vaping THC compared with nicotine.

SUMMARY

Findings provide up-to-date information on vaping as a way to consume a drug, whether THC or nicotine. Harm reduction benefits were shown in a year-long follow-up of smoking cessation; harms continue to accumulate, including from passive consumption.

The impact of a comprehensive tobacco product flavor ban in San Francisco among young adults

OBJECTIVE

Flavors play an important role in the initiation and use of tobacco products. The FDA, states, and cities have been implementing or considering banning flavored e-cigarettes or any flavored tobacco products. This study empirically assessed the impact of one of the first comprehensive bans of all flavored tobacco products other than tobacco-flavored e-cigarettes among young adults in San Francisco, California.

METHODS

Using Amazon Mechanical Turk, a sample of San Francisco residents aged 18-34 who previously used tobacco products (N = 247) were surveyed about their tobacco use both before and after the ban. Descriptive statistics and regression models were applied.

RESULTS

The prevalence of overall flavored tobacco use decreased from 81% and 85% to 69% and 76% for 18-24 years and 25-34 years old, respectively. The prevalence of flavored e-cigarettes decreased from 57% and 56% to 45% and 48% for 18-24 years and 25-34 years old, respectively. The prevalence of cigars uses reduced as well. However, cigarette smoking increased, although not statistically significant among 25-34 years old. 66% of participants did not support the ban and 65% believed the ban had not been enforced completely. Most users reported being able to obtain flavored tobacco products in multiple ways despite the ban.

CONCLUSIONS

These findings suggest that comprehensive local flavor bans, by themselves, cannot sharply reduce the availability or use of flavored tobacco products among residents. Nevertheless, local bans can still significantly reduce overall e-cigarette use and cigar smoking but may increase cigarette smoking.

Effect of flavour manipulation on ENDS (JUUL) users' experiences, puffing behaviour and nicotine exposure among US college students

SIGNIFICANCE

Electronic nicotine delivery system (ENDS) use has continued to increase exponentially among young people in the USA, with unique flavours being one of the most cited reasons for use. Yet, controlled studies examining the effects of restricting flavour are lacking. This study evaluates the impact of ENDS flavour manipulation on user's puffing behaviour, subjective experience, harm perception and nicotine exposure among college-aged ENDS users.

METHODS

JUUL users (n=30, age 18 to 24 years) attended two 60 min ad libitum ENDS use sessions (JUUL preferred flavour vs JUUL classic tobacco flavour) in a cross-over design. Puff topography and plasma nicotine concentration were measured, and participants completed subjective experience questionnaires.

RESULTS

Increases were observed on measures of satisfaction, taste, enjoyment, urges to vape/smoke, pleasure, product appeal and increased concentration following using the preferred flavour pod (p values <0.05). Compared with preferred flavour, participants in the tobacco flavour were less motivated to use it in the future (70.9 vs 19.1 scores, p<0.001), even if it was the only product on the market (75.8 vs 30.7 scores, p<0.001). While nicotine levels significantly increased in both conditions from pre to post session (p values <0.001), no significant differences were observed in nicotine boost levels or on puff topography parameters when comparing both flavour conditions.

CONCLUSIONS

This pilot study provides evidence that ENDS flavours have a substantial effect in enhancing young current ENDS users' experiences, product appeal and motivation to use the product in the future. It highlights that limiting flavours could play a potential role when designing strategic policies to reduce the appeal of ENDS use among young people.

Alternative flavored and unflavored tobacco product use and cigarette quit attempts among current smokers experiencing homelessness

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Almost two-thirds of participants used alternative tobacco products.

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Cigars, blunts, and e-cigarettes most commonly used alternative tobacco products.

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Most cigar and e-cigarette users used fruit-flavored tobacco products.

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Discordance found between perceptions of addiction/harm and alternative tobacco use.

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Alternative tobacco product use was not associated with a past-year quit attempt.

Introduction

Alternative tobacco product (ATP) use is common in the general population; however, few studies have explored ATP among individuals experiencing homelessness. We recruited individuals experiencing homelessness who were current cigarette smokers to explore flavored and unflavored ATP use and its association with past-year cigarette quit attempts.

Methods

Using time-location sampling, we recruited participants from eight service sites in San Francisco, CA between December 2017 and July 2018. We explored type of ATP use and perceptions of product addiction, harm and risk between cigarette-only smokers and those who used cigarettes and ATPs (‘ATP users’). We used logistic regression to examine the association between ATP and past-year quit attempts, adjusting for demographics, substance use disorders, depressive symptoms, and cigarette use characteristics.

Results

Among the 470 participants, 34.5% were cigarette-only users and 65.5% were ATP users. Among ATP users, 74.0% used cigars and 29.8% used e-cigarettes in the past month, with fruit-flavored products being the most common. ATP users were more likely to perceive cigars, blunts, and smokeless tobacco to be quite to extremely harmful or addictive compared to cigarette-only users. ATP use was not associated with past-year quit attempts, whereas hazardous alcohol use (OR = 2.07; CI 1.07–4.02) was associated with higher odds and and amphetamine use (OR = 0.50; CI 0.26–0.98) was associated with lower odds of past-year attempts.

Conclusions

High rates of ATP use highlight a need for studies that explore motivations for use, beyond use as a smoking cessation aid, among people experiencing homelessness.

Chemical Characterization of Electronic Cigarette (e-cigs) Refill Liquids Prior to EU Tobacco Product Directive Adoption: Evaluation of BTEX Contamination by HS-SPME-GC-MS and Identification of Flavoring Additives by GC-MS-O

The present study focused on the determination of benzene, toluene, ethylbenzene and xylenes (BTEX) concentration levels in 97 refill liquids for e-cigs selected by the Italian National Institute of Health as representative of the EU market between 2013 and 2015 prior to the implementation of the European Union (EU) Tobacco Product Directive (TPD). Most of the e-liquids investigated (85/97) were affected by BTEX contamination, with few exceptions observed (levels below the limit of quantification (LOQ) of headspace-solid phase micro extraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) methodology). Across brands, concentration levels ranged from 2.7 to 30,200.0 µg/L for benzene, from 1.9 to 447.8 µg/L for ethylbenzene, from 1.9 to 1,648.4 µg/L for toluene and from 1.7 to 574.2 µg/L for m,p,o-xylenes. The variability observed in BTEX levels is likely to be related to the variability in contamination level of both propylene glycol and glycerol and flavoring additives included. No correlation was found with nicotine content. Moreover, on a limited number of e-liquids, gas chromatography-mass spectrometry-olfactometry (GC-MS-O) analysis was performed, allowing the identification of key flavoring additives responsible of specific flavor notes. Among them, diacetyl is a flavoring additive of concern for potential toxicity when directly inhaled into human airways. The data reported are eligible to be included in the pre-TPD database and may represent a reference for the ongoing evaluation on e-liquids safety and quality under the current EU Legislation.

Radiologic, Pathologic, Clinical, and Physiologic Findings of Electronic Cigarette or Vaping Product Use-associated Lung Injury (EVALI): Evolving Knowledge and Remaining Questions

Proposed as a safer alternative to smoking, the use of electronic cigarettes has not proven to be innocuous. With numerous deaths, there is an increasing degree of public interest in understanding the symptoms, imaging appearances, causes of, and treatment of electronic cigarette or vaping product use-associated lung injury (EVALI). Patients with EVALI typically have a nonspecific clinical presentation characterized by a combination of respiratory, gastrointestinal, and constitutional symptoms. EVALI is a diagnosis of exclusion; the patient must elicit a history of recent vaping within 90 days, other etiologies must be eliminated, and chest imaging findings must be abnormal. Chest CT findings in EVALI most commonly show a pattern of acute lung injury on the spectrum of organizing pneumonia and diffuse alveolar damage. The pathologic pattern found depends on when in the evolution of the disease process the biopsy sample is taken. Other less common forms of lung injury, including acute eosinophilic pneumonia and diffuse alveolar hemorrhage, have also been reported. Radiologists and pathologists help play an important role in the evaluation of patients suspected of having EVALI. Accurate and rapid identification may decrease morbidity and mortality by allowing for aggressive clinical management and glucocorticoid administration, which have been shown to decrease the severity of lung injury in some patients. In this review, the authors summarize the current state of the art for the imaging and pathologic findings of this disorder and outline a few of the major questions that remain to be answered.

E-cigarette flavored pods induce inflammation, epithelial barrier dysfunction, and DNA damage in lung epithelial cells and monocytes

E-cigarette flavored pods are increasing in use among young adults. Although marketed as a safer alternative to conventional cigarettes, the health effects of e-cigarette flavored pods are unknown. We hypothesized that e-cigarette flavored pods would cause oxidative stress, barrier dysfunction, and an inflammatory response in monocytes and lung epithelial cells. JUUL pod flavors (Fruit Medley, Virginia Tobacco, Cool Mint, Crème Brulee, Cool Cucumber, Mango, and Classic Menthol) and similar pod flavors (Just Mango-Strawberry Coconut and Caffé Latte) were tested. These pod flavors generated significant amounts of acellular ROS and induced significant mitochondrial superoxide production in bronchial epithelial cells (16-HBE). Lung epithelial cells (16-HBE, BEAS-2B) and monocytes (U937) exposed to various pod aerosols resulted in increased inflammatory mediators, such as IL-8 or PGE₂. JUUL pod flavors, Crème Brulee and Cool Cucumber, caused epithelial barrier dysfunction in 16-HBE cells. Moreover, tested flavors also showed DNA damage upon exposure in monocytes. We determined the chemical constituents present in various flavors. Our data suggest that these constituents in flavored pods induce oxidative stress, inflammation, epithelial barrier dysfunction, and DNA damage in lung cells. These data provide insights into the regulation of e-cigarette flavored pods, as well as constituents in these flavors.

Electronic cigarettes: Tumultuous times

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