Smoking Behavior and Exposure: Results of a Menthol Cigarette Cross-over Study

The Scientific Basis for the Regulation of Flavors in Tobacco Products

Effective tobacco policies are important for reducing the harm of tobacco use and can have a broad impact at the population level. This review provides an overview of how clinical science can inform tobacco policies with a focus on policies related to flavored tobacco products, using menthol cigarettes as an illustrative example. Specifically, this review summarizes the role of flavors in tobacco use and the history of regulation of flavored tobacco products by the US Food and Drug Administration (FDA), provides an overview of clinical research methods used to contribute to the scientific evidence to inform FDA tobacco policies, discusses key findings related to menthol tobacco products using these methods, and proposes future directions for clinical research. As the tobacco marketplace continues to evolve with new products and flavor chemicals, ongoing clinical science will be essential for establishing evidence-based policies to protect public health and reduce tobacco-related health disparities.

Switching people who smoke to unfiltered cigarettes: Effects on smoking topography

Introduction

Smoking topography (ST) describes smoking behavior and patterns. Removal of the cigarette filter and subsequent impact on ST has not been investigated. This is the first clinical trial comparing ST for filtered and unfiltered cigarettes in a naturalistic experiment.

Methods

We conducted a crossover clinical trial following established people who smoke cigarettes (n = 32) for two weeks under filtered and unfiltered smoking experimental conditions. Participants (50 % female, mean age 38.3 yr.) smoked in each experimental condition followed by a 3-week post-washout period. ST (puff count, volume, duration, peak and average flow) was measured at six time-points. Statistical analysis included a linear repeated mixed-effects model of smoking experimental conditions by visit number and sex.

Results

Average flow (ml/sec) was significantly less for filtered smoking (-6.92 lower (95 % CI: -13.44 to -0.39), p < 0.05), thus demonstrating more resistance on inhalation. No significant differences were found between filtered or unfiltered experimental conditions for other ST variables. However, average volume and average peak flow were somewhat higher in unfiltered smoking, and lower mean puff counts/cigarette were observed for unfiltered compared to filtered smoking.

Conclusion

Lower average flow rates were associated with filtered cigarette smoking. No significant differences were found for other ST variables between smoking experimental conditions. ST measurements comparing cigarette smoking conditions may determine if product regulatory changes, such as removing the cigarette filter could impact smoking behavioral patterns among people who smoke. This proof-of-principle study measuring ST may be replicated in larger trials to determine potential behavioral changes in smoking unfiltered cigarettes.

Addiction potential of combustible menthol cigarette alternatives: a randomised cross-over trial

INTRODUCTION

The Food and Drug Administration (FDA) has issued proposed product standards banning menthol as a characterising flavour in cigarettes and cigars. The public health benefits of these product standards may be attenuated by the role of plausible substitutes in the marketplace. Therefore, the present study examined the addiction potential of plausible combustible menthol alternatives compared with usual brand menthol cigarettes (UBMC).

METHODS

Ninety-eight adult menthol cigarette smokers completed four visits, smoking their UBMC at the first session and three menthol cigarette alternatives in random order at the subsequent visits: (1) a preassembled menthol roll-your-own (mRYO) cigarette using menthol pipe tobacco and mentholated cigarette tube, (2) a menthol filtered little cigar (mFLC) and (3) a non-menthol cigarette (NMC). Measures of smoking topography, exhaled carbon monoxide (CO), craving and withdrawal, subjective effects and behavioural economic demand indices were assessed.

RESULTS

Compared with UBMC, menthol cigarette alternatives resulted in different puffing topography and CO exposure (except mRYO), and lower levels of positive subjective experience and behavioural economic demand indices. Among the alternative products, participants reported the highest level of positive subjective experience and higher demand for mRYO, compared with mFLC and NMC. Similarly, participants were significantly more likely to want to try again, purchase and use the mRYO product regularly compared with mFLC and NMC.

CONCLUSIONS AND RELEVANCE

mRYO cigarettes were the most highly rated cigarette alternative among study products, suggesting their potential appeal as a menthol cigarette substitute and needed inclusion of menthol pipe tobacco and cigarette tubes in FDA's proposed ban.

Effects of liquid nicotine concentration and flavour on the acceptability of electronic nicotine delivery systems (ENDS) among people who smoke participating in a randomised controlled trial to reduce cigarette consumption

BACKGROUND

Research is needed to understand the acceptability of electronic nicotine delivery systems (ENDS) as a smoking reduction aid. This study examines the acceptability of ENDS by liquid nicotine concentration and flavour among people who smoke using ENDS to reduce their smoking.

METHODS

People who smoke cigarettes but were naïve to ENDS participated in a double-blind randomised controlled trial to reduce conventional cigarette smoking. Participants were randomised to either a control cigarette substitute (CS) or one of three ENDS groups; 0 mg/mL, 8 mg/mL or 36 mg/mL nicotine concentration. ENDS flavour was chosen by the participant (tobacco or menthol). Participants reported their CS, ENDS and cigarettes per day (CPD) from the past 7 days at 1-month, 3-month and 6-month follow-up visits. Participants also reported side effects and measures of satisfaction, psychological reward, aversion and craving relief. Outcome variables were modelled using linear mixed effects by the following groups: liquid nicotine concentration, flavour and a flavour-nicotine concentration interaction.

RESULTS

Participants (n=520) were 41.2% male, 67.3% white, had a mean age of 46.2 years and smoked a mean of 18.6 CPD (SD=7.74) at baseline. All flavour and concentration groups decreased CPD from baseline to all follow-up visits with the 36 mg/mL experiencing the greatest reduction, compared with the 0 mg/mL and 8 mg/mL groups. All groups except the 36 mg/mL group decreased their product use over time. The use of menthol flavour was associated with fewer side effects at 3 months (p=0.02) and lesser aversion at 1 month (p=0.03) compared with tobacco-flavoured ENDS. The 36 mg/mL group experienced the greatest craving relief and greatest aversion compared with other groups.

CONCLUSIONS

Both nicotine concentration and flavour appear to have independent, as well as interactive, effects that influence ENDS acceptability among people who use cigarettes.

Tax incidence for menthol cigarettes by race: Evidence from Nielsen Homescan data

We use Nielsen Homescan data to examine whether the incidence of cigarette taxes on menthol products varies with race. We find that taxes are shifted at significantly lower rates to Black smokers of menthol cigarettes than any other smokers. One possible explanation is that the industry targets price promotions to Black menthol smokers because they tend to be more responsive to cigarette prices relative to other smokers. We find evidence that Black smokers receive significantly more price discounts for menthol products than white menthol smokers. Our findings indicate that increasing cigarette taxes would effectively reduce menthol smoking among Black Americans because tax pass-through rate for Black menthol smokers is still substantially above zero.

Heterogeneous deposition of regular and mentholated little cigar smoke in the lungs of Sprague-Dawley rats

BACKGROUND

Quantifying the dose and distribution of tobacco smoke in the respiratory system is critical for understanding its toxicity, addiction potential, and health impacts. Epidemiologic studies indicate that the incidence of lung tumors varies across different lung regions, suggesting there may be a heterogeneous deposition of smoke particles leading to greater health risks in specific regions. Despite this, few studies have examined the lobar spatial distribution of inhaled particles from tobacco smoke. This gap in knowledge, coupled with the growing popularity of little cigars among youth, underscores the need for additional research with little cigars.

RESULTS

In our study, we analyzed the lobar deposition in rat lungs of smoke particles from combusted regular and mentholated Swisher Sweets little cigars. Twelve-week-old male and female Sprague-Dawley rats were exposed to smoke particles at a concentration of 84 ± 5 mg/m3 for 2 h, after which individual lung lobes were examined. We utilized Inductively Coupled Plasma Mass Spectrometry to quantify lobar chromium concentrations, serving as a smoke particle tracer. Our findings demonstrated an overall higher particle deposition from regular little cigars than from the mentholated ones. Higher particle deposition fraction was observed in the left and caudal lobes than other lobes. We also observed sex-based differences in the normalized deposition fractions among lobes. Animal study results were compared with the multi-path particle dosimetry (MPPD) model predictions, which showed that the model overestimated particle deposition in certain lung regions.

CONCLUSIONS

Our findings revealed that the particle deposition varied between different little cigar products. The results demonstrated a heterogenous deposition pattern, with higher particle deposition observed in the left and caudal lobes, especially with the mentholated little cigars. Additionally, we identified disparities between our measurements and the MPPD model. This discrepancy highlights the need to enhance the accuracy of models before extrapolating animal study results to human lung deposition. Overall, our study provides valuable insights for estimating the dose of little cigars during smoking for toxicity research.

Heaviness of smoking index in menthol and non-menthol smokers

BACKGROUND

It has been hypothesized that menthol in cigarettes increases dependence. Several studies suggest that menthol and non-menthol smokers have similar or lower levels of dependence, but those studies are not without limitations. The Heaviness of Smoking Index (HSI) is a widely accepted, validated measure of cigarette dependence.

OBJECTIVES

This report aims to provide further evidence regarding dependence among menthol and non-menthol smokers, as indicated by daily smoking and as measured by the HSI.

METHODS

Survey data from 27,131 adult smokers were analyzed to compare the percent of menthol and non-menthol smokers who are daily smokers, and the percentage who are low or high HSI dependence. Logistic regressions were also conducted to determine if menthol use predicts daily smoking, and low or high dependence after controlling for demographic differences.

RESULTS

Comparisons among weighted samples of adult smokers demonstrate that menthol smokers were consistently more likely to be non-daily smokers, more likely to be in the low dependence category, and less likely to be in the high dependence category on the HSI as compared to non-menthol smokers. Logistic regression confirmed that when controlling for age, gender, race/ethnicity, and education, relative to non-menthol smokers, menthol smokers had no difference in odds of being in the low dependence HSI category and significantly lower odds of being a daily smoker, and of being in the high dependence category.

CONCLUSIONS

These analyses support the conclusion that, based on the HSI, menthol smokers are not more cigarette dependent than non-menthol smokers, and may be less dependent.

Electronic Cigarette Nicotine Flux, Nicotine Yield, and Particulate Matter Emissions: Impact of Device and Liquid Heterogeneity

INTRODUCTION

Electronic cigarettes (ECIGs) heat a nicotine-containing liquid to produce an inhalable aerosol. ECIG power (wattage) and liquid nicotine concentration are two factors that predict nicotine emission rate ("flux"). These factors can vary greatly across devices and users.

AIMS AND METHODS

The purpose of this study was to examine ECIG device and liquid heterogeneity in "real world" settings and the association with predicted nicotine flux, nicotine yield, and total particulate matter (TPM) emissions. Past 30-day ECIG users (n = 84; mean age = 23.8 years [SD = 9.6]) reported device and liquid characteristics. Device power was measured via multimeter, device display screens, or obtained via labeling. Liquid nicotine concentration was obtained via labeling or through chemical analysis. Predicted nicotine flux, nicotine yield, and TPM associated with 10 4-second puffs were calculated for participants' primary devices.

RESULTS

Participants' primary devices were box mods (42.9%), disposable vapes (20.2%), and pod mods (36.9%). Most participants (65.5%) reported not knowing their primary device wattage. Rebuildable/box mods had the greatest power range (11.1-120.0 W); pod mod power also varied considerably (4.1-21.7 W). Unlike device wattage, most participants (95.2%) reported knowing their liquid nicotine concentration, which ranged from 3.0 to 86.9 mg/ml (M = 36.0, SD = 29.3). Predicted nicotine flux varied greatly across products (range =12.0-160.1 μg/s, M = 85.6 μg/s, SD = 34.3). Box mods had the greatest variability in wattage and predicted nicotine flux, nicotine yield, and TPM yield.

CONCLUSIONS

ECIG device and liquid heterogeneity influence nicotine and other toxicant emissions. Better measurement of ECIG device and liquid characteristics is needed to understand nicotine and toxicant emissions and to inform regulatory policy.

IMPLICATIONS

ECIG device and liquid heterogeneity cause great variability in nicotine flux and toxicants emitted. These data demonstrate the need to examine device and liquid characteristics to develop empirically informed, health-promoting regulatory policies. Policies may include setting product standards such that ECIG products cannot (1) have nicotine fluxes much greater than that of a cigarette to decrease the risk of dependence, (2) have nicotine fluxes that are very low and thus would have minimal appeal to cigarette smokers and may serve as starter products for youth or nontobacco users, and (3) emit large amounts of particulate matter and other toxicants.

Mouth Level Intake of Nicotine from Three Brands of Little Filtered Cigars with Widely Differing Product Characteristics Among Adult Consumers

Little filtered cigars are tobacco products with many cigarette-like characteristics. However, despite cigars falling under the U.S. Food and Drug Administration regulatory authority, characterizing flavors, which are still allowed in little filtered cigars, and filter design may influence how people use the products and the resulting exposure to harmful and potentially harmful constituents. We estimated nicotine mouth level intake (MLI) from analyses of little cigar filter butt solanesol levels, brand characteristics, carbon monoxide boost, and puff volume in 48 dual cigarette/cigar users during two repeat bouts of ad lib smoking of three little filtered cigar brands. Mean nicotine MLI for the three brands was significantly different with Swisher Sweets (0.1% ventilation) Cherry at 1.20 mg nicotine, Cheyenne Menthol (1.5%) at 0.63 mg, and Santa Fe unflavored (49%) at 0.94 mg. The association between nicotine MLI and puff volume was the same between Cheyenne Menthol and Santa Fe unflavored. However, these were different from Swisher Sweets Cherry. At least five main factors─flavor, ventilation, filter design, nicotine delivery related to tar, and user puff volume─may directly or indirectly impact MLI and its association with other measures. We found that users of little filtered cigars that have different filter ventilation and flavor draw dissimilar amounts of nicotine from the product, which may be accompanied by differences in exposure to other harmful smoke constituents.

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.

Longitudinal associations between flavored tobacco use and tobacco product cessation in a national sample of adults

Use of flavored tobacco has been associated with lower likelihood of short-term abstinence from tobacco. It is unknown whether longer-term associations exist, particularly for a variety of products and specific flavor categories. This study used adult survey data from the Population Assessment of Tobacco and Health (PATH) Study (2013-2018). We tested associations of past 30-day tobacco product use at wave 2 using both a 2-category any flavor versus unflavored variable and 4-category specific flavor (menthol/mint, sweet, and both menthol/mint and sweet) versus unflavored variable with past 12-month cessation from the same product two years later at wave 4. Separate models were run for each product (combustible cigarettes, cigars, hookah, e-cigarettes, and smokeless), adjusting for wave 1 sociodemographic characteristics. For all five products, past 30-day use of any flavored (versus unflavored) product at wave 2 was associated with reduced likelihood of same-product cessation at wave 4. Most specific flavor categories were associated with reduced odds of same-product cessation across all products. Any flavor use was also associated with reduced likelihood of longer-term cessation (i.e., past 24-months at both waves 3 and 4) and cessation from all five tobacco products in several analyses. Exploratory moderation results indicated that the association between e-cigarette flavor use and lower likelihood of cessation was stronger for young adults (18-24) versus older adults (25+). Current use of flavored tobacco products is associated with lower likelihood of product cessation. Flavored tobacco products warrant consideration in regulatory policy to reduce the adverse public health impact of tobacco use.

Use of Menthol Cigarettes, Smoking Frequency, and Nicotine Dependence Among US Youth

IMPORTANCE

Menthol may make cigarette smoke less aversive and could lead youth to smoke more frequently and become more dependent on nicotine.

OBJECTIVE

To assess the association of menthol use with cigarette smoking frequency and nicotine dependence (ND) among youth cigarettes users.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used a pooled sample of cohorts of US youth (aged 12-17 years at their baseline and follow-up interviews) in the Population Assessment of Tobacco and Health Study (September 2013 to November 2019). Household interviews were conducted using audio computer-assisted self-interviews. US youth who were past-30-day cigarette smokers at any of wave 2 through wave 5, completed the preceding survey (eg, wave 2 past-30-day cigarette smokers completed wave 1), and indicated whether they used menthol cigarettes were eligible. The association of menthol use with smoking frequency and ND was estimated using inverse probability of treatment weighting adjusted mean differences (aMDs), adjusted risk ratios (aRRs), and corresponding 95% CIs. Data were analyzed from December 2021 to March 2022.

EXPOSURES

Menthol use and transitions in use (switching to or from menthol cigarettes).

MAIN OUTCOMES AND MEASURES

Main outcomes were the number of days smoked in the past 30 days, the risk of frequent smoking (smoking ≥20 days in the past 30 days), and symptoms of ND.

RESULTS

There were a total of 1492 observations among 1096 US youth cigarette smokers, of whom 49.4% were female, 67.2% were non-Hispanic White, and 28.7% were aged 12 to 14 years at their baseline survey (all percentages are weighted). Among those who switched from not smoking to smoking (61% of the sample), menthol use was associated with smoking on 3.1 additional days (aMD; 95% CI, 1.9 to 4.2 days), 59% higher risk of being a frequent smoker (aRR, 1.59; 95% CI, 1.23 to 2.06), and 10% higher ND scores (aMD, 1.09; 95% CI, 1.02 to 1.17). Switching from smoking menthol to smoking nonmenthol (vs maintaining menthol use) was associated with smoking on 3.6 fewer days (aMD; 95% CI, -6.3 to -0.9 days) and 47% lower risk of being a frequent smoker (aRR, 0.68; 95% CI, 0.50 to 0.92).

CONCLUSIONS AND RELEVANCE

These findings suggest that the addition of menthol to cigarettes is associated with increased smoking frequency and ND among US youth.

Naturalistic Topography Assessment in a Randomized Clinical Trial of Smoking Unfiltered Cigarettes: Challenges, Opportunities, and Recommendations

Smoking topography (ST) is a set of measures profiling the behavioral characteristics of smoking in various settings. The CReSS portable device can measure ST in the natural environment. No standard protocol exists for measuring ST longitudinally with the CReSS. This study examined the utilization of the CReSS to measure ST and highlights challenges and opportunities in a naturalistic setting. This study is part of a randomized cross-over clinical trial of smoking filtered or unfiltered cigarettes. Participants (n = 43) smoked in each study condition for two weeks using the CReSS device for five days in their naturalistic smoking setting. The devices were calibrated and cleaned during the washout period, and data were downloaded every visit. Five test puffs were administered to calibrate each device. Moderate compliance rates (74.1%) were found with device usage, and the issues encountered were overheating/clogging, incorrectly registered date/time-stamped data, and device repair/replacement. Routine inspection/cleaning and training in device usage were instrumental in mitigating device malfunctioning. The CReSS device proved to be a feasible tool to examine naturalistic smoking topography and the potential impact of changes in tobacco product design on smoking unfiltered cigarettes. This is the first study to examine ST variables longitudinally, measured at multiple time points, and using unfiltered cigarettes.

Isotope-Dilution Gas Chromatography-Mass Spectrometry Method for the Selective Detection of Nicotine and Menthol in E-Cigarette, or Vaping, Product Liquids and Aerosols

We developed a quantitative method for analyzing nicotine and menthol in e-cigarette, or vaping, products (EVPs). These products may adversely impact health through inhalational exposure to addictive and harmful chemicals. The presence of unknown substances in do-it-yourself e-liquids, counterfeits, or unregulated products may increase exposure to harmful chemicals, as underscored by the 2019 EVP use-associated lung injury (EVALI) outbreak. To minimize these risks, it is important to accurately quantify nicotine and menthol in e-liquids and aerosol emissions to evaluate EVP authenticity, verify product label accuracy, and identify potentially hazardous products. We developed a simple, versatile, high-throughput method using isotope-dilution gas chromatography-mass spectrometry for quantifying nicotine and menthol concentrations in both e-liquid contents and machine-generated aerosol emissions of EVPs. Rigorous validation has demonstrated that the method is specific, precise (CV<2.71%), accurate (percent error ≤7.0%), and robust. Linear calibration ranges from 0.01 to 1.00 mg/ml for both analytes was achieved, corresponding to expected analyte levels in e-liquids and machine-generated EVP aerosols. Limits of detection (LODs) in the final 10-ml sample extract were 0.4 μg/ml for nicotine and 0.2 μg/ml for menthol. The method was used to analyze aerosol emissions of 141 EVPs associated with the 2019 EVALI outbreak; detectable levels of nicotine (2.19–59.5 mg/g of aerosol) and menthol (1.09–10.69 mg/g of aerosol) were observed in 28 and 11%, respectively, of the samples analyzed. Nicotine was not detected in any of the tetrahydrocannabinol (THC), cannabidiol (CBD), or oil-based products, while menthol (2.95 mg/g of aerosol) was only detected in one of these products (THC-labeled). The analytical method can be used to quantify nicotine and menthol concentrations in the e-liquids and aerosols from a range of EVPs, and these findings highlight a difference between e-cigarette and other vaping products.

A Low-Cost, High-Throughput Digital Image Analysis of Stain Patterns on Smoked Cigarette Filter Butts to Estimate Mainstream Smoke Exposure

Standard machine smoking protocols provide useful information for examining the impact of design parameters, such as filter ventilation, on mainstream smoke delivery. Unfortunately, their results do not accurately reflect human smoke exposure. Clinical research and topography devices in human studies yield insights into how products are used, but a clinical setting or smoking a cigarette attached to such a device may alter smoking behavior. To better understand smokers' use of filtered cigarette products in a more natural environment, we developed a low-cost, high-throughput approach to estimate mainstream cigarette smoke exposure on a per-cigarette basis. This approach uses an inexpensive flatbed scanner to scan smoked cigarette filter butts and custom software to analyze tar-staining patterns. Total luminosity, or optical staining density, of the scanned images provides quantitative information proportional to mainstream smoke-constituent deliveries on a cigarette-by-cigarette basis. Duplicate sample analysis using this new approach and our laboratory's gold-standard liquid chromatography/tandem mass spectrometry (LC/MS/MS) solanesol method yielded comparable results (+7% bias) from the analysis of 20 commercial cigarettes brands (menthol and nonmentholated). The brands varied in design parameters such as length, filter ventilation, and diameter. Plots correlating the luminosity to mainstream smoked-nicotine deliveries on a per-cigarette basis for these cigarette brands were linear (average R2 > 0.91 for nicotine and R2 > 0.83 for the tobacco-specific nitrosamine NNK), on a per-brand basis, with linearity ranging from 0.15 to 3.00 mg nicotine/cigarette. Analysis of spent cigarette filters allows exposures to be characterized on a per-cigarette basis or a "daily dose" via summing across results from all filter butts collected over a 24 h period. This scanner method has a 100-fold lower initial capital cost for equipment than the LC/MS/MS solanesol method and provides high-throughput results (~200 samples per day). Thus, this new method is useful for characterizing exposure related to filtered tobacco-product use.

Differences in Cognitive Task Performance, Reinforcement Enhancement, and Nicotine Dependence Between Menthol and Nonmenthol Cigarette Smokers

INTRODUCTION

Menthol has been shown to target similar brain regions and neural receptors as nicotine, yet the association between menthol cigarette use and cognitive performance remains unknown.

AIMS AND METHODS

This study examined differences in cognitive task performance between menthol (MS) and nonmenthol (NMS) cigarette smokers after acute cigarette consumption. Sixty white and black and/or African American, nonabstinent, MS (n = 30) and NMS (n = 30) were assessed presmoking and postsmoking their preferred cigarette on four computerized tasks: Continuous Performance Task (CPT; alerting attention), N-Back Task (working memory), Finger Tapping Task (motor control), and Apple Picker Task (reinforcement enhancement). Self-reported nicotine dependence and objective smoking topography measures were also compared between groups.

RESULTS

Initial unadjusted analyses showed a significant effect of cigarette type × time on CPT speed (p = .042), where MS improved while NMS group worsened in CPT speed after smoking. After controlling for baseline cigarette craving and cigarette nicotine levels, the effect of cigarette type × time for all cognitive outcomes was statistically nonsignificant (ps > .05). However, there remained a significant effect of cigarette type, where MS versus NMS had poorer CPT (p = .046) and N-Back Task accuracy (p = .006) but faster N-Back speed (p = .039). There were no statistically significant differences between groups on reinforcement enhancement, nicotine dependence, or smoking behavior outcomes (ps > .05).

CONCLUSIONS

Contrary to our hypotheses, results did not find a significant effect of cigarette type on the change in cognitive performance after acute smoking in nonabstinent smokers. Further studies are needed to clarify the specific pharmacological effects of nicotine and menthol on cognitive functioning.

IMPLICATIONS

The current study is the first to compare the potential enhancement of cognitive task performance after acute cigarette smoking between satiated menthol and nonmenthol cigarette smokers. Study results suggest that acute menthol cigarette use may not enhance cognitive function above and beyond nonmenthol cigarettes to increase dependence among menthol smokers. However, the contribution of other psychological factors (eg, craving, mood) and cigarette characteristics (eg, nicotine content) may be involved in cognitive function enhancement to perpetuate dependence and smoking persistence for menthol smokers.

Effects on smoking behavior of switching menthol smokers to non-menthol cigarettes

INTRODUCTION

Bans of menthol characterizing flavor in cigarettes have been implemented in some localities and have been proposed more broadly. One proposed benefit of such a ban is to increase cessation rates among current menthol smokers. There is currently relatively limited data regarding how smoking behavior changes if menthol smokers switch to non-menthol cigarettes.

METHODS

African American menthol smokers interested in quitting smoking were randomized to either continue smoking menthol (n=60) or switch to non-menthol cigarettes (n=62) for one month prior to a cessation attempt. Cessation results were reported previously; this analysis reports the results from the pre-cessation visits at which amount smoked, exhaled carbon monoxide concentration (CO), urinary cotinine concentrations and subjective measures were assessed.

RESULTS

Over the four-week study period, those switching to non-menthol (vs. continuing to smoke menthol) cigarettes smoked fewer cigarettes per day (mean ratio: 0.86; 95% CI: 0.76, 0.98; p=0.02), reported lower withdrawal symptom severity (mean difference -1.29; 95% CI: -2.6 to -0.01; p=0.05) and higher perceived effectiveness of their skills for quitting smoking (mean difference 0.56; 95% CI: 0.02 to 1.10; p=0.05). No significant differences were found between groups in exhaled CO, urinary cotinine concentrations or most other subjective effects including support for a ban on menthol characterizing flavor in cigarettes.

CONCLUSIONS

These results suggest that were menthol cigarettes no longer available, those that switch to non-menthol cigarettes would not change their smoking behavior in a way that is likely to be more hazardous, with some indicators suggesting that there may be some benefit.

IMPLICATIONS

A ban on menthol characterizing flavor in cigarettes has been proposed as a potential means by which to increase smoking cessation rates among current menthol cigarette smokers. This study evaluated how African American menthol cigarette smokers adjusted their smoking behavior after switching to non-menthol cigarettes. Although the overall differences between groups were modest, they were in a direction consistent with decreased smoking suggesting that current smokers would not adjust their behavior in a way that is likely to be more hazardous, with some indicators suggesting that there may be some benefits.

Differences in Smoking Topography and Subjective Responses to Smoking Among African American and White Menthol and Non-Menthol Smokers

INTRODUCTION

It has been suggested that menthol increases exposure to harmful elements of smoking and makes smoking more rewarding, easier to initiate, and harder to quit. Isolating the direct effects of menthol is challenging as African American (AA) race and menthol preference are highly overlapping. This study evaluated smoking behavior and subjective responses among a balanced sample of AA and white menthol and non-menthol smokers. In addition, smoking topography (ST) was compared to naturalistic smoking (NS) and interactions with menthol and race were explored.

AIMS AND METHODS

Smokers (N = 100) smoked and rated their preferred brand of cigarettes via ST or NS during two laboratory visits (counterbalanced).

RESULTS

Controlling for baseline differences among the groups (eg, nicotine dependence), menthol smokers took shorter and smaller puffs and AA smokers took longer puffs, but there were no differences in total puff volume, carbon monoxide, or other ST parameters. Menthol smokers reported greater urge reduction and lower sensory stimulation. The smoking method (ST vs. NS) had no effects on smoking behavior or exposure. Cigarettes smoked via ST were rated stronger. Differences in satisfaction based on the smoking method interacted with race and menthol status. Ratings of aversion differed by race and menthol status.

CONCLUSIONS

Menthol was not associated with increased smoke exposure or reward (except for urge reduction). ST caused minimal experimental reactivity relative to NS. Additional research that isolates the effects of menthol and examines potential interactive effects with race and other variables is needed to better understand its role in smoking-related health disparities.

IMPLICATIONS

Menthol and non-menthol smokers differed on some demographic variables and menthol preference was associated with greater nicotine dependence and greater urge reduction after smoking. Menthol was not associated with greater smoke exposure. Future research that investigates the unique risks associated with menthol and examines potential interactive effects with race and other related variables is warranted to better understand the role of menthol in smoking-related health disparities.

The Biological Impact of Menthol on Tobacco Dependence

In the 1920s, tobacco companies created a marketing campaign for what would one day be their most profitable series of products: mentholated tobacco cigarettes. Menthol provides the smoker with a pleasant mint flavor in addition to a cooling sensation of the mouth, throat, and lungs, giving relief from the painful irritation caused by tobacco smoke. Promising a healthier cigarette using pictures of doctors in white coats and even cartoon penguins, tobacco companies promoted these cigarettes to young, beginner smokers and those with respiratory health concerns. Today, smoking tobacco cigarettes causes one in five US Americans to die prematurely, crowning it as the leading cause of preventable death. In contrast to the dubious health claims by tobacco companies, mentholated cigarettes are in fact more addictive. Smokers of mentholated cigarettes have lower successful quit rates and in some cases are resistant to both behavioral and pharmacological treatment strategies. There is now considerable evidence, especially in the last 5 years, that suggest menthol might influence the addictive potential of nicotine-containing tobacco products via biological mechanisms. First, menthol alters the expression, stoichiometry, and function of nicotinic receptors. Second, menthol's chemosensory properties operate to mask aversive properties of using tobacco products. Third, menthol's chemosensory properties aid in serving as a conditioned cue that can both enhance nicotine intake and drive relapse. Fourth, menthol alters nicotine metabolism, increasing its bioavailability. This review discusses emerging evidence for these mechanisms, with an emphasis on preclinical findings that may shed light on why menthol smokers exhibit greater dependence.

IMPLICATIONS

Mentholated cigarettes have been shown to have greater addictive potential than their nonmentholated counterparts. Evidence is pointing toward multiple mechanisms of action by which menthol may alter tobacco dependence. Understanding menthol's biological functions as it pertains to nicotine dependence will be helpful in crafting novel pharmacotherapies that might better serve menthol smokers. In addition, a better understanding of menthol's pharmacology as it relates to tobacco dependence will be valuable for informing policy decisions on the regulation of mentholated cigarettes.

Health Care Utilization of Menthol and Non-menthol Cigarette Smokers

INTRODUCTION

To study the association between health care utilization and menthol cigarette use and whether the association differed between African American (AA) and non-AA smokers.

METHODS

We analyzed the three most recent 2005, 2010, and 2015 National Health Interview Survey Cancer Control Supplements. After incorporating propensity score weights adjusting for observed differences between menthol and non-menthol users, we estimated Zero-Inflated Poisson models on hospital nights, emergency department visits, doctor visits, and home visits as a function of menthol use status and other covariates separately for current cigarette smokers and recent quitters (former smokers quitting cigarette smoking ≤ 4 years).

RESULTS

Although current menthol smokers smoked fewer cigarettes per day than current non-menthol smokers, they did not differ from current non-menthol smokers in health care utilization. Among recent quitters, those who used to smoke menthol cigarettes had higher odds of having hospital nights than those who used to smoke non-menthol cigarettes. However, we did not find any significant association between menthol use and other health care utilization-emergency department visits, doctor visits, and home visits-among recent quitters. Moreover, compared with non-AA recent quitters, AA recent quitters had higher odds of having home visits, but fewer home visits, if they used to smoke menthol cigarettes.

CONCLUSION

Menthol use was associated with greater hospitalization among recent quitters, and the association between home visits and menthol use differed between AA and non-AA recent quitters.

IMPLICATIONS

This is the first study that used econometric models to study the association between health care utilization and menthol cigarette use and examine whether the association differed between AA and non-AA smokers. Our study found health care utilization did not differ by menthol use status for current smokers, although current menthol smokers smoked fewer cigarettes per day than current non-menthol smokers. However, we found menthol use was associated with higher odds of having hospital nights for recent quitters. We also found AA recent quitters had a different association between home visits and menthol use compared with non-AA recent quitters.

Menthol additives to tobacco products. Reasons for withdrawing mentholated cigarettes in European Union on 20th may 2020 according to tobacco products directive (2014/40/EU)

Menthol, which is a natural cyclic monoterpene alcohol with a minty smell, is one of the main constituents of essential oils that naturally occur in some aromatic plants, such as Mentha × piperita L. This natural compound shows many biological properties, such as anesthetic, analgesic, antibacterial and antifungal, immunomodulating, and skin penetration-enhancing. It is added to a variety of goods, such as food, oral-care products, OTC products, cosmetics, and tobacco products. Menthol is not just a simple flavoring agent, especially when it comes to tobacco products. Its ability to 'mask' the negative effects of nicotine and its additional positive sensory effects makes it the most common additive in such products. For the customers, mentholated tobacco products may be mistakenly perceived as less harmful for health, which may increase their consumption. However, as the evidence shows, menthol cigarettes are no safer than conventional cigarettes and may lead to more frequent disease exacerbation during prolonged exposure to smoke from such products. In addition, because of its complex interactions with nicotine, menthol may affect smoking behavior and may increase addiction to nicotine. For those reasons, the European Union banned flavored cigarettes (whose sale size reached more than 3% of the total tobacco product market) by implementing the Tobacco Products Directive (2014/40/EU) on 20th May 2020. While the menthol ban was based on health concerns, the ultimate effect on consumers, regarding potential quitting, is yet to be determined.

Characteristic Human Individual Puffing Profiles Can Generate More TNCO than ISO and Health Canada Regimes on Smoking Machine When the Same Brand Is Smoked

Human smoking behavior influences exposure to smoke toxicants and is important for risk assessment. In a prospective observational study, the smoking behavior of Marlboro smokers was measured for 36 h. Puff volume, duration, frequency, flow and inter-puff interval were recorded with the portable CReSSmicro™ device, as has often been done by other scientists. However, the use of the CReSSmicro™ device may lead to some registration pitfalls since the method of insertion of the cigarette may influence the data collection. Participants demonstrated consistent individual characteristic puffing behavior over the course of the day, enabling the creation of a personalized puffing profile. These puffing profiles were subsequently used as settings for smoking machine experiments and tar, nicotine and carbon monoxide (TNCO) emissions were generated. The application of human puffing profiles led to TNCO exposures more in the range of Health Canada Intense (HCI)-TNCO emissions than for those of the International Standardization Organization (ISO). Compared to the ISO regime, which applies a low puff volume relative to human smokers, the generation of TNCO may be at least two times higher than when human puffing profiles were applied on the smoking machine. Human smokers showed a higher puffing intensity than HCI and ISO because of higher puffing frequency, which resulted in more puffs per cigarette, than both HCI and ISO.

Measures of dependence in menthol and nonmenthol smokers - A comprehensive narrative review

Introduction. More than a decade ago, concerns were raised that menthol in cigarettes might enhance addiction to smoking. This article provides a comprehensive review of published studies examining cigarette dependence among menthol and nonmenthol smokers. The purpose of the review is to evaluate the scientific evidence to determine if menthol increases cigarette dependence. Materials and Methods. The published literature was searched in 2019 for studies that provide evidence on cigarette dependence among menthol compared to nonmenthol smokers. Included in this review are published studies that compare menthol and nonmenthol smokers based on widely accepted and validated measures of dependence, or other established predictors of dependence (age of smoking initiation [first cigarette]/age of progression [regular/daily smoking]) and indicators of dependence (smoking frequency, cigarettes smoked per day, time to first cigarette after waking, night waking to smoke, smoking duration). Results and Conclusion. Based on a review of the available studies, including those with adjusted results and large representative samples, reliable and consistent empirical evidence supports a conclusion that menthol smokers are not more dependent than nonmenthol smokers and thus menthol in cigarettes does not increase dependence.

Distress Intolerance and Smoking Topography in the Context of a Biological Challenge

INTRODUCTION

Distress intolerance (DI), one's perceived or behavioral incapacity to withstand distress, is implicated in psychopathology and smoking. This study evaluated the effect of DI on smoking reinforcement in the context of a carbon dioxide (CO2) biological challenge.

METHODS

Adult daily smokers (n = 90; 48.9% female) were randomized to receive a single inhalation/breath of 35% CO2-enriched air (n = 45) or compressed room air (n = 45). Perceived DI was assessed before the challenge. Smoking reinforcement was examined via average post-challenge puff volume across puffs and at the puff-to-puff level.

RESULTS

Higher DI was associated with an increased average puff volume (b = -4.7, p = .031). CO2 produced decreased average puff volume compared with room air (b = -7.7, p = .018). There was a DI* condition interaction (ƒ2 = 0.02), such that CO2 decreased average puff volume compared with room air in smokers with higher DI (b = -13.9, t = -3.06, p = .003), but not lower DI. At the puff-to-puff level, there was a significant interaction between DI, condition, and cubic time (b = 0.0003, p =. 037). Specifically, room air produced large initial puff volumes that decreased from puff to puff over the cigarette for high- and low-DI smokers. CO2 produced persistent flat volumes from puff to puff over the cigarette for higher DI smokers, whereas CO2 produced puff volumes like that of room air in lower DI smokers.

DISCUSSION

Findings suggest DI heightens smoking reinforcement generally, and in the context of intense cardiorespiratory distress, is associated with stable and persistent smoking. DI is a promising therapeutic target that, if addressed through psychological intervention, may improve cessation outcomes by decreasing smoking reinforcement.

IMPLICATIONS

This study contributes to our understanding of the relationship between DI and smoking reinforcement, via examining these processes in response to acute cardiorespiratory distress. Specifically, we found that smokers who are less tolerant of distress, as opposed to those who are more tolerant, evince a decrease in average puff volume, and consistently low puff-to-puff volume, in response to a biological stressor. These findings suggest that smokers high in DI alter smoking behavior following acute cardiorespiratory distress, perhaps to reduce overstimulation, yet also persist in smoking in a manner that suggests an inability to achieve satiation.

Effects of Menthol Flavor Cigarettes or Total Urinary Menthol on Biomarkers of Nicotine and Carcinogenic Exposure and Behavioral Measures

INTRODUCTION

The effects of either menthol flavor cigarettes or total urinary menthol on nicotine dependence, biomarkers of addictive and carcinogenic exposure, and behavioral measures may inform differences and similarities of these two approaches.

METHODS

Stratified recruitment by cigarette (menthol flavor or regular) and race (African American and white) yielded a balanced sample of 136 adult smokers in a 36-hour inpatient protocol. Exposure measures assessed during 24-hour data collection included urinary menthol, total NNAL [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol], 10 polycyclic aromatic hydrocarbon metabolites, baseline plasma cotinine, plasma nicotine pre- and post-smoking, exhaled carbon monoxide pre- and post-smoking, and cigarette puff volumes. The latter three were measured at four specified timepoints throughout the day.

RESULTS

There were no significant differences between menthol flavor and regular cigarette smokers in measures of nicotine dependence, biomarkers of addictive and carcinogenic exposures, or behavioral measures. Significant race × cigarette type interaction effects were found for two biomarkers: plasma nicotine and 3-hydroxyphenanthrene. Total urinary menthol was significantly associated with higher levels of nearly all dependent variables including puff volume, exhaled carbon monoxide, plasma nicotine and cotinine, NNAL, and polycyclic aromatic hydrocarbons. The significant effects of total urinary menthol were sustained after adjusting for menthol flavor and regular cigarette type and other covariates (eg, number of cigarettes per day, baseline cotinine, and baseline nicotine).

CONCLUSIONS

Urinary menthol is an independent predictive biomarker for nicotine dependence, addictive and carcinogenic exposure, and behaviors.

IMPLICATIONS

Comparison of the effects of menthol flavor and total urinary menthol on nicotine dependence, biomarkers of addictive and carcinogenic exposure, and behavioral measures emphasizes the important significant contribution of total urinary menthol concentrations in contrast to no significant associations by dichotomous cigarette type with these biomarkers.

Menthol cigarette use in young adult smokers with severe mental illnesses

INTRODUCTION

Smokers with severe mental illness (SMI) are more likely to start smoking and less likely to quit. Menthol may facilitate smoking progression, dependence, and maintenance by reducing harshness and irritation from smoking and providing a unique sensory experience during use. High rates of menthol use have been reported in smokers with SMI, but information on young adults with SMI has not been reported.

METHODS

This study provides a secondary analysis to assess the impact of menthol use in a pilot trial of brief tobacco interventions. Participants were assessed at baseline and again at a 3-month follow-up with structured interviews and breath carbon monoxide to confirm self-reported 7-day abstinence at follow-up.

RESULTS

Participants included 81 young adult smokers with SMI, mean age of 24.2 years (SD = 3.6; range 18-30). Overall, 58% of the group reported that they recently used a menthol-flavored product. Menthol use was correlated with race (African American [18/21, 85.7%] vs. White [24/53, 45.3%] or other race [5/7, 71.4%]; χ2 = 10.7, p = .005) and more lifetime psychiatric hospitalizations (t = 2.39, p = .02), but not with cigarettes per day, nicotine dependence, quit attempts over the follow-up period, nor with achieving biologically confirmed abstinence at the follow-up assessment.

CONCLUSIONS

The high prevalence of menthol-flavored cigarette use in this study group is consistent with previous reports of high rates of menthol use among young adults, Blacks, and middle-aged SMI smokers. This study supports existing evidence that policies to restrict menthol flavoring in combustible tobacco products could reduce smoking in young adults with SMI.

IMPLICATIONS

High rates of menthol use have been reported in middle-aged smokers with SMI, but information on young adults with SMI has not been reported. In this study, more than half (58%) of 81 young adult smokers with SMI used a menthol-flavored product. Menthol use was associated with race and with history of psychiatric hospitalizations. The research supports existing evidence that policies to restrict menthol flavoring in combustible tobacco products could reduce smoking in young adults with SMI.

Smoking Topography among Korean Smokers: Intensive Smoking Behavior with Larger Puff Volume and Shorter Interpuff Interval

The difference of smoker’s topography has been found to be a function many factors, including sex, personality, nicotine yield, cigarette type (i.e., flavored versus non-flavored) and ethnicity. We evaluated the puffing behaviors of Korean smokers and its association with smoking-related biomarker levels. A sample of 300 participants was randomly recruited from metropolitan areas in South Korea. Topography measures during a 24-hour period were obtained using a CReSS pocket device. Korean male smokers smoked two puffs less per cigarette compared to female smokers (15.0 (13.0–19.0) vs. 17.5 (15.0–21.0) as the median (Interquartile range)), but had a significantly larger puff volume (62.7 (52.7–75.5) mL vs. 53.5 (42.0–64.2) mL); p = 0.012). The interpuff interval was similar between men and women (8.9 (6.5–11.2) s vs. 8.3 (6.2–11.0) s; p = 0.122) but much shorter than other study results. A dose-response association (p = 0.0011) was observed between daily total puff volumes and urinary cotinine concentrations, after controlling for sex, age, household income level and nicotine addiction level. An understanding of the difference of topography measures, particularly the larger puff volume and shorter interpuff interval of Korean smokers, may help to overcome a potential underestimation of internal doses of hazardous byproducts of smoking.

Impact of E-cigarettes on Smoking and Related Outcomes in Veteran Smokers With Psychiatric Comorbidity

OBJECTIVE

Compared to the general U.S. population, smokers with comorbid psychiatric and/or substance use disorders have lower quit rates after evidence-based treatments and disproportionately high smoking-related deaths. Improved modalities for reducing tobacco-related harm in this subpopulation are needed. Because electronic cigarettes (e-cigarettes) can now deliver physiologically relevant levels of nicotine to consumers, they represent an additional nicotine delivery system that could be used in cessation interventions. While current data suggest that the use of e-cigarettes by smokers promotes a reduction in combustible cigarette use, smoking quit rates through use of e-cigarettes appears to be low. The goal of this study was to examine impact of e-cigarette use on combustible tobacco use as well as on the readiness to quit smoking and changes in nicotine dependence in a multimorbid population.

METHODS

We conducted a 4-week, open-label study in 43 military veteran smokers who had no immediate intention to stop smoking and were currently receiving psychiatric services from the Department of Veterans Affairs health care system. Participants were provided with a study e-cigarette they could use ad libitum along with other tobacco products and were encouraged to attend weekly laboratory visits and a one-month follow-up visit. Main outcome measures were number of cigarettes smoked per day (CPD), the frequency of e-cigarette use, the amount of money spent on combustible cigarettes (U.S. dollars/week), alveolar carbon monoxide (CO) levels, and urine cotinine levels.

RESULTS

Mean e-cigarette use was 5.7 days per week and only 9% of participants used the e-cigarette for fewer than 4 days per week. Significant reductions in breath CO (9.3 ppm to 7.3 ppm, p < .02) and CPD (from 16.6 to 5.7, p < .001) were observed across study weeks, and no serious adverse events were reported. Three participants (10% of completers) reported smoking cessation that was corroborated biochemically. At one-month follow-up, motivation to quit smoking remained significantly higher and the level of nicotine dependence was significantly lower than at baseline.

CONCLUSIONS

E-cigarettes are acceptable to smokers with psychiatric comorbidities, as indicated by sustained and frequent e-cigarette use by 90% of participants, and may promote reduction and/or cessation of combustible cigarette use. E-cigarettes appear to be a viable harm reduction modality in smokers with psychiatric comorbidities.