ENDS Flavor Preference by Menthol Cigarette Smoking Status among US Adults, 2018-2019

Assessment of abuse liability and switching potential of menthol-flavored pod-based electronic nicotine delivery systems among US adults who smoke cigarettes

BACKGROUND

Menthol-flavored electronic nicotine delivery systems (ENDS) are a focus of public health and regulatory policy considerations. The abuse liability of five menthol-flavored pod-based ENDS was compared to combustible cigarettes, and switching potential of ENDS was also evaluated.

METHODS

215 US adults who smoke cigarettes (34.4% female; mean age[SD]=29.60[8.75]; 40.9% non-Hispanic White; mean cigarettes/day[SD]=12.04[8.52]) completed a randomized 6-arm within-person cross-over product-use study. Participants used five pod-based menthol-flavored ENDS (JUUL2 Polar Menthol 1.5%, JUUL2 Prototype Fresh Menthol 3.0%, JUUL Menthol 5.0%, Vuse Alto Menthol 5.0%, NJOY Ace Menthol 5.0%) and their usual brand (UB) cigarette for 20minutes ad libitum. After each product use, subjective reinforcing effects relevant to abuse liability and associated with switching away from cigarettes (e.g., satisfaction, product liking) were assessed.

RESULTS

All ENDS products were rated substantially and statistically significantly lower than UB cigarette on measures of subjective reinforcing effects (ps<0.001). Satisfying effects of JUUL2 1.5% were rated significantly higher than other ENDS products. JUUL2 Prototype 3.0% and Vuse Alto 5.0% did not significantly differ (ps>0.05), and both were rated significantly higher than JUUL 5.0% and NJOY Ace 5.0% (ps<0.05). Differences in subjective responses to study products did not significantly differ by preference for menthol cigarettes or by current ENDS use.

CONCLUSIONS

Abuse liability of all menthol-flavored ENDS in this study was substantially lower than combustible cigarettes. Abuse liability of JUUL2 1.5% was within the range of currently marketed pod-based menthol-flavored ENDS products. JUUL2 1.5% likely has high potential for facilitating switching among US adults who smoke.

Menthol versus non-menthol flavouring and switching to e-cigarettes in black and Latinx adult menthol combustible cigarette smokers: secondary analyses from a randomised clinical trial

BACKGROUND

As the US Food and Drug Administration takes regulatory action on menthol cigarettes, debate continues about how restricting menthol e-liquids might impact adult menthol smokers in switching to e-cigarettes.

METHODS

Switching patterns and e-cigarette acceptability were assessed at week 6 among 64 black and Latinx menthol cigarette smokers who used JUUL menthol (n=39) or non-menthol e-cigarettes ((n=25), primarily mint or mango) as part of a randomised switching trial.

RESULTS

No clear evidence of effects was found between menthol versus non-menthol e-cigarettes on use or subjective effects/acceptability, effect sizes for all comparisons were small (effect size=0.0-0.2), and Bayes factor ranged from 0.10 to 0.15. Specifically, 82.1% of participants who used menthol-flavoured e-cigarettes fully or partially switched to e-cigarettes compared with 88.0% of participants who used a non-menthol (p=0.75). Further, both groups demonstrated substantial reductions in cigarettes per day (menthol e-cigarettes: -8.5±10.4 vs non-menthol e-cigarettes: -8.8±5.8, p=0.87), comparable grams of e-liquid consumed (menthol e-cigarettes: 9.2±9.8 g vs non-menthol e-cigarettes: 11.0±11.0 g, p=0.47), and positive subjective effects, including 'just right' throat hit (menthol e-cigarettes: 70.7% vs non-menthol e-cigarettes: 66.7%, p=0.93) and flavour liking (menthol e-cigarettes: 75.6% vs non-menthol e-cigarettes: 66.7%, p=0.32).

CONCLUSIONS

Both menthol and non-menthol e-cigarettes were associated with high rates of use and acceptability among menthol smokers. Findings require confirmation in a fully powered non-inferiority or equivalence study but provide preliminary evidence to inform regulatory action on menthol e-cigarettes that could slow youth initiation without impacting black and Latinx menthol cigarette smokers interested in switching to e-cigarettes.

TRIAL REGISTRATION NUMBER

NCT03511001.

Ice flavours and non-menthol synthetic cooling agents in e-cigarette products: a review

E-cigarettes with cooling flavours have diversified in ways that complicate tobacco control with the emergence of: (1) Ice-hybrid flavours (eg, 'Raspberry Ice') that combine cooling and fruity/sweet properties; and (2) Products containing non-menthol synthetic cooling agents (eg, Wilkinson Sword (WS), WS-3, WS-23 (termed 'koolada')). This paper reviews the background, chemistry, toxicology, marketing, user perceptions, use prevalence and policy implications of e-cigarette products with ice-hybrid flavours or non-menthol coolants. Scientific literature search supplemented with industry-generated and user-generated information found: (a) The tobacco industry has developed products containing synthetic coolants since 1974, (b) WS-3 and WS-23 are detected in mass-manufactured e-cigarettes (eg, PuffBar); (c) While safe for limited oral ingestion, inhalational toxicology and health effects from daily synthetic coolant exposure are unknown and merit scientific inquiry and attention from regulatory agencies; (d) Ice-hybrid flavours are marketed with themes incorporating fruitiness and/or coolness (eg, snow-covered raspberries); (e) WS-23/WS-3 concentrates also are sold as do-it-yourself additives, (f) Pharmacology research and user-generated and industry-generated information provide a premise to hypothesise that e-cigarette products with ice flavours or non-menthol cooling agents generate pleasant cooling sensations that mask nicotine's harshness while lacking certain aversive features of menthol-only products, (g) Adolescent and young adult use of e-cigarettes with ice-hybrid or other cooling flavours may be common and cross-sectionally associated with more frequent vaping and nicotine dependence in convenience samples. Evidence gaps in the epidemiology, toxicology, health effects and smoking cessation-promoting potential of using these products exist. E-cigarettes with ice flavours or synthetic coolants merit scientific and regulatory attention.

The Role of Flavored Electronic Nicotine Delivery Systems in Smoking Cessation: A Systematic Review

Background

Electronic nicotine delivery systems (ENDS) come in numerous flavors and may aid smoking cessation. This systematic review examines evidence on the role of ENDS flavors in smoking cessation.

Methods

We searched EMBASE OVID, PsychInfo, and Medline databases for studies that: 1) examined cigarette cessation outcomes for persons using ENDS (intent, attempts, and success) and 2) reported results separated by respondent's ENDS flavor used. We extracted crude and adjusted odds ratios for associations between cessation outcomes and types of ENDS flavors used (nontobacco vs. tobacco/unflavored; nontobacco and nonmenthol vs. tobacco/unflavored and menthol). We did not consider cessation outcomes among people not using ENDS. We evaluated the evidence using the GRADE approach, focusing on consistency and reliability of findings across studies.

Results

29 studies met inclusion criteria, producing 36 odds ratios (ORs) comparing cessation outcomes across ENDS flavor groups. Three ORs examined quit intent, five examined quit attempts, and 28 examined quit success. Using GRADE, we reached Low levels of certainty that there was not an association between ENDS flavor use and intention to quit smoking or making a quit attempt. There were Very Low levels of certainty that nontobacco flavored versus tobacco/unflavored ENDS use was not associated with smoking cessation success, with similar findings for nonmenthol and nontobacco compared to tobacco and menthol flavored ENDS.

Conclusion

The evidence about the role of different flavored ENDS use and smoking cessation outcomes is inconclusive, reflecting highly heterogeneous study definitions and methodological limitations. More high-quality evidence, ideally from randomized controlled trials, is required.

Characteristics and Patterns of Cigarette Smoking and Vaping By Past-Year Smokers Who Reported Using Electronic Nicotine Delivery System to Help Quit Smoking in the Past Year: Findings From the 2018-2019 Tobacco Use Supplement to the Current Population Survey

INTRODUCTION

Cigarette smoking has declined, while electronic nicotine delivery system (ENDS) use has increased in the United States. Understanding the role of ENDS in adult smoking quit attempts and cessation is important for estimating their population health impact.

AIMS AND METHODS

We used data from 2018 to 2019 tobacco use supplement to the current population survey to examine demographic characteristics and ENDS use patterns among adult ENDS users who reported quitting smoking in the past year by trying to switch to ENDS ("switchers") and smokers who did or did not make a quit attempt in the past year. χ2 tests of proportions and t-tests were used to compare characteristics between groups.

RESULTS

In 2018-2019, about three-quarters of switchers reported daily use of ENDS compared to only one-third of dual users with a recent quit attempt by trying to switch to ENDS. Compared to dual users who made a quit attempt by trying to switch to ENDS, switchers were more likely to use menthol/mint-flavored ENDS exclusively (5.6% vs. 13.1%; p = .004) but less likely to use tobacco-flavored ENDS exclusively (21.2% vs. 13.7%; p = .01).

CONCLUSIONS

ENDS users who quit smoking in the past year and reported trying to quit by switching to ENDS were more likely to use menthol/mint flavors exclusively and use ENDS daily compared to dual users who made a quit attempt by trying to switch to ENDS. Longer-term prospective data may better clarify the role of ENDS in smoking quit attempts and cessation.

IMPLICATIONS

This study provides information on patterns of ENDS use in former smokers and current smokers who tried to quit smoking by switching to ENDS in a national sample of U.S. adults. These results can inform policy actions concerning ENDS products.

Effect of restricting menthol flavored cigarettes or E-cigarettes on smoking behavior in menthol smokers

Bans of menthol characterizing flavor in tobacco products have been enacted in some localities and proposed in the United States for cigarettes. To gather data regarding how restrictions for menthol in cigarettes and e-cigarettes may affect current menthol cigarette smokers, 37 African American menthol smokers participated in a pilot study in which they were asked to abstain (n = 18) or not abstain from menthol cigarettes (n = 19) for 8-weeks. All participants received menthol flavored e-cigarettes for 4 weeks and tobacco flavored e-cigarettes for 4 weeks in random order. Number of cigarettes smoked per day (estimated mean ratio [EMR] = 0.31; 95% CI: 0.13, 0.72) and exhaled CO concentrations (EMR = 0.61; 95% CI: 0.43, 0.88) were lower in the menthol cigarette abstainer group compared to the menthol cigarette non-abstainer group. Those in the menthol cigarette abstainer group reported higher scores on motivation to quit (p = 0.03) and perceived effectiveness of quitting skills (p = 0.02). There were no substantial effects seen in amount smoked or exhaled CO based on flavor of e-cigarettes provided. Higher e-cigarette use (based on reported puffs per day) was reported in the menthol cigarette abstainer (vs. non-abstainer) group (p < 0.01) and also during the 4-week period when provided with menthol (vs. tobacco) e-cigarettes (p < 0.01). These data suggest that the potential of e-cigarettes to reduce tobacco related harm may be enhanced if combined with a ban on menthol flavor in combustible cigarettes. Larger studies are needed to determine the effect of limiting menthol in e-cigarettes on smoking behavior among current menthol smokers.

Assessment of worker chemical exposures in California vape shops

E-cigarettes are battery-operated devices that heat a liquid mixture to make an aerosol that is inhaled, or vaped, by the user. Vape shops are retail environments designed to fulfill customer demand for diverse e-liquid flavors and hardware options, which create unique worker exposure concerns. To characterize exposures to vape shop workers, especially to flavoring chemicals associated with known respiratory toxicity, this study recruited vape shops from the San Francisco Bay Area. In six shops, we measured air concentrations for volatile organic compounds, formaldehyde, flavoring chemicals, and nicotine in personal and/or area samples; analyzed components of e-liquids vaped during field visits; and assessed metals on surface wipe samples. Interviews and observations were conducted over the course of a workday in the same six shops and interviews were performed in an additional six where sampling was not conducted. Detections of the alpha-diketone butter flavoring chemicals diacetyl and/or 2,3-pentanedione were common: in the headspace of purchased e-liquids (18 of 26 samples), in personal air samples (5 of 16), and in area air samples (2 of 6 shops). Two exceedances of recommended exposure limits for 2,3-pentanedione (a short-term exposure limit and an 8-hr time-weighted average) were measured in personal air samples. Other compounds detected in the area and personal air samples included substitutes for diacetyl and 2,3-pentanedione (acetoin and 2,3-hexanedione) and compounds that may be contaminants or impurities. Furthermore, a large variety (82) of other flavoring chemicals were detected in area air samples. None of the 12 shops interviewed had a health and safety program. Six shops reported no use of any personal protective equipment (PPE) (e.g., gloves, chemical resistant aprons, eye protection) and the others stated occasional use; however, no PPE use was observed during any field investigation day. Recommendations were provided to shops that included making improvements to ventilation, hygiene, use of personal protective equipment, and, if possible, avoidance of products containing the alpha-diketone flavoring chemicals. Future research is needed to evaluate the long-term health risks among workers in the vape shop retail industry and for e-cigarette use generally. Specific areas include further characterizing e-liquid constituents and emissions, evaluating ingredient health risks, evaluating the contributions of different routes of exposure (dermal, inhalation, and ingestion), and determining effective exposure mitigation measures.

Differences in switching away from cigarettes and JUUL use characteristics among adult menthol and nonmenthol smokers who purchased the JUUL System

OBJECTIVES

Studies have assessed switching away from cigarettes among adult smokers who use electronic nicotine delivery systems (ENDS), but there is little data assessing differences in likelihood of switching or ENDS use characteristics by menthol smoking.

METHODS

Adult (age ≥ 21) established smokers who purchased a JUUL Starter Kit (N = 15,036) completed baseline and 1-, 2-, 3-, 6-, 9- and 12-month assessments. Switching (no past-30-day cigarette smoking) and flavor use were assessed at each follow-up. Repeated-measure logistic regression models evaluated association of menthol smoking and switching across 1 year.

RESULTS

Across the 6 follow-ups, more menthol smokers primarily used Menthol/Mint-flavored JUULpods (53.8%) than nonmenthol smokers (22.9%). Only 6.4% of menthol smokers primarily used Tobacco flavors (vs. 25.9% of nonmenthol smokers). Across all follow-ups menthol smokers (41.2% of sample) were more likely to switch than nonmenthol smokers (42.6% vs. 38.8%: OR [95% CI] = 1.17 [1.11, 1.23]); this association remained significant after adjustment for sociodemographic, smoking and JUUL use covariates (aOR [95% CI] = 1.13 [1.05, 1.21]). Nonmenthol smokers, but not menthol smokers, were significantly more likely to switch when primarily using Menthol/Mint-flavored (vs. Tobacco-flavored) JUULpods (aOR [95% CI] = 1.14 [1.04, 1.25]). Differences in baseline smoking characteristics between menthol and nonmenthol smokers were small in magnitude.

CONCLUSIONS

Adult menthol (vs. nonmenthol) smokers using JUUL were more likely to switch. More than twice as many menthol (vs. nonmenthol) smokers primarily used Menthol/Mint-flavor JUULpods; few menthol smokers used tobacco flavors. Given these pronounced differences in flavor preferences, availability of ENDS in menthol flavors may be particularly important for menthol smokers, but may also benefit some nonmenthol smokers.

A longitudinal study of menthol cigarette use and smoking cessation among adult smokers in the US: Assessing the roles of racial disparities and E-cigarette use

Using nationally representative longitudinal data from Wave 1 to Wave 4 of the Population Assessment of Tobacco and Health Study in the United States, we examined whether the association between menthol cigarette use and smoking cessation was modified by race/ethnicity and e-cigarette use. Multivariable discrete-time survival models were fit to an unbalanced person-period data set (person n = 7423, risk period n = 18,897) for adult respondents (ages 25+) who were current established cigarette smokers at baseline. We found that adults who smoke menthol cigarettes had lower odds of smoking cessation, but the effect was modified by race/ethnicity as non-Hispanic (NH) Black menthol smokers had lower odds of quitting smoking than NH White or Hispanic menthol smokers. We also found that e-cigarette use was associated with higher odds of smoking cessation among both menthol and non-menthol smokers, but the association was stronger among menthol smokers. Our results suggest that a menthol smoking ban may have a favorable impact on smoking cessation for NH Black adults. In addition, our results also suggest that a menthol smoking ban may be more effective if menthol smokers have access to e-cigarettes as a way to quit cigarette use.

Changes in Biomarkers of Cigarette Smoke Exposure After 6 Days of Switching Exclusively or Partially to Use of the JUUL System with Two Nicotine Concentrations: A Randomized Controlled Confinement Study in Adult Smokers

Introduction

Evidence suggests that cigarette smokers who switch to electronic nicotine delivery systems (ENDS) reduce their exposure to harmful toxicants and carcinogens. It is unclear if dual-use is associated with decreases in exposure to toxicants.

Methods

This parallel-group confinement study assessed changes in biomarkers of exposure (BOEs) over six days among healthy adult smokers who were randomized into 1 of 11 study groups: eight JUUL-brand System (JUUL) groups (4 JUUL flavors [Virginia Tobacco, Menthol, Mint, Mango] × 2 nicotine concentrations [5.0% or 3.0% by weight]); Dual-Use group used preferred JUUL flavor (5.0% nicotine) and ≤50% usual brand (UB) cigarettes/day; UB Cigarette group and one group abstained from all tobacco/nicotine product use (Abstinence group). Urine and blood analysis assessed changes in primary BOE endpoints (NNAL, 3-HPMA, MHBMA, S-PMA COHb) and secondary BOE endpoints (NNN, HMPMA, CEMA, 1-OHP, O-toluidine, 2-NA, 4-ABP) among 279 adult smokers.

Results

In JUUL groups, median percent reductions in primary BOEs (Day 6–Baseline) were 90%–≥100% of Abstinence; there were no significant differences between JUUL groups and Abstinence. All reductions in JUUL groups were substantially and statistically significantly greater than reductions in the UB Cigarette group (ps < 0.025). Median reductions in primary BOEs in the Dual-Use group were 43%–55% of Abstinence. Similar results were observed for secondary BOEs.

Conclusion

This study suggests that the use of JUUL as a complete or partial substitute (i.e., dual-use with ≥50% reduction in cigarette consumption) for combustible cigarettes can substantially reduce exposure to multiple toxins associated with cigarette smoking.

Implications

This study adds to the growing body of evidence supporting the utility of ENDS products as potentially reduced-harm alternatives to cigarettes for adult smokers. Adult smokers who switched completely from cigarette smoking to use of the JUUL System (“JUUL”) in two nicotine concentrations (5.0% and 3.0%) and four flavors significantly reduced their exposure to multiple classes of cigarette-related toxicants. Additionally, smokers who used JUUL and continued smoking but reduced their daily cigarette consumption by ≥50% (dual users) also significantly reduced their toxicant exposure compared to cigarette smoking.