Menthol's potential effects on nicotine dependence: a tobacco industry perspective

Comparison of Carcinogen Biomarkers in Smokers of Menthol and Nonmenthol Cigarettes: The 2015-2016 National Health and Nutrition Examination Survey Special Sample

BACKGROUND

The US FDA announced its commitment to prohibiting menthol as a characterizing flavor in tobacco. The relationship between cigarette menthol and exposure to toxic substances in mainstream tobacco smoke is not well characterized.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2015 to 2016 special sample were used to study markers of 26 harmful and potentially harmful constituents (HPHC) in tobacco smoke. These include urine metabolites of polycyclic aromatic hydrocarbons (PAH), volatile organic compounds (VOC), and heavy metals in exclusive menthol (n = 162) and nonmenthol (n = 189) cigarette smokers. Urine metabolites of 7 PAHs, 15 VOCs, and 4 heavy metal biomarkers were compared by menthol status. Multivariable analyses were conducted on creatinine-adjusted concentrations.

RESULTS

There were no significant differences in cotinine levels or in 22 of 26 HPHCs. Among the urine metabolites of PAHs, the levels of 1-hydroxyphenanthrene were about 16% lower in menthol smokers. Among the urine metabolites of VOCs, menthol cigarette smokers presented significantly lower concentrations of acrylamide, N,N-dimethylformamide, and acrylonitrile. Menthol and nonmenthol smokers presented similar levels of heavy metals. Menthol did not affect the levels of cotinine and the nicotine metabolite ratio in urine.

CONCLUSIONS

Menthol and nonmenthol cigarettes deliver similar levels of most HPHCs.

IMPACT

Findings on toxicity are similar for menthol and nonmenthol 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.

Smoking cessation strategies used by former menthol cigarette smokers after a menthol ban

INTRODUCTION

Menthol cigarettes were banned in Ontario, Canada on January 1st, 2017. We used concept mapping, a mixed-method approach, to describe how menthol cigarette smokers quit smoking after the Ontario menthol ban.

METHODS

Pre-ban daily and non-daily menthol cigarette smokers who reported smoking abstinence 24 months after the ban (n = 62; 53.2% women; mean age = 43.6, SD = 12.5) generated statements describing reasons and strategies for smoking cessation/reduction after the menthol ban. Participants sorted a final list of 57 statements into groups of similar content and rated statements on how true each statement was for them and multidimensional scaling analysis identified thematic clusters.

RESULTS

Six clusters were identified: Mental and Environment Changes, Direct Ban Impacts, Health Reasons, Cues to Action, Family and Friends, and Cessation Strategies. The highest rated statements (i.e., most true) suggested many participants were motivated to quit smoking before or after the ban and 30.7% of participants believed the menthol ban helped with smoking cessation. Some of the lowest rated statements included using nicotine replacement therapy products, medication (i.e., Champix), or other tobacco products suggesting these strategies were less common. Statement ratings suggested many smokers quit without using replacement products or medication, but modifying cognitions and avoiding smoking cues were common.

CONCLUSIONS

The menthol ban aided some menthol smokers to quit, while others reported the ban did not play a role in smoking cessation. These data suggest the menthol ban had direct and indirect effects on smoking reduction behavior. Campaigns supporting similar bans that target both types of effects will likely be most effective for smoking reduction.

Prior Daily Menthol Smokers More Likely to Quit 2 Years After a Menthol Ban Than Non-menthol Smokers: A Population Cohort Study

BACKGROUND AND AIMS

The province of Ontario, Canada, banned the use of menthol-flavored tobacco products as of January 1, 2017. This study aims to assess the longer-term impact of a menthol ban on smoking behavior at 2 years, which is unknown.

METHODS

Population cohort study with baseline survey (n = 1821) conducted September-December 2016 and follow-up survey January-August 2019 among current smokers in Ontario (16+) prior to the menthol ban. Poisson regression was used to assess the probability of quitting smoking by pre-ban menthol status, controlling for differences in smoking and demographic characteristics, with multiple imputations used to address missing data.

FINDINGS

Menthol smokers were more likely to report having quit smoking (12% [daily menthol] and 10% [occasional menthol] vs. 3% [non-menthol]; p < .001) than non-menthol smokers in the 2 years after a menthol ban. After adjustment for smoking and demographic characteristics, daily menthol smokers had higher likelihood of quitting smoking (adjusted relative risk [ARR] 2.08; 95% confidence interval [CI] 1.20-3.61) and reported more quit attempts (ARR 1.45; 95% CI 1.15-1.82). Among those who attempted to quit, menthol smoking was not associated with relapse (daily ARR = 0.96; 95% CI: 0.86, 1.07; occasional ARR = 0.99; 95% CI: 0.90, 1.08). However, there was a statistically significant interaction among menthol users who reported using other flavored tobacco products 1 year after the ban (ARR = 0.26 [95% CI: 0.08, 0.90]).

CONCLUSIONS

The study found increased probability of quitting among daily menthol smokers and more quit attempts among daily and occasional menthol smokers compared with non-menthol smokers in Ontario 2 years after the implementation of a menthol ban.

IMPLICATIONS

This study examines quitting behavior 2 years after a menthol ban in Ontario, Canada. Those who were daily menthol smokers prior to the ban were more likely to quit smoking and make more quit attempts in the 2 years after the ban. While there was no difference in the likelihood of relapse between menthol and non-menthol smokers among those who attempt to quit, there were indications that pre-ban daily menthol smokers who used other tobacco products after the ban were likely to quit.

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.

Trends and Associations of Menthol Cigarette Smoking Among US Middle and High School Students-National Youth Tobacco Survey, 2011-2018

INTRODUCTION

Youth cigarette smoking decreased significantly over the last two decades in the United States. This study provides estimates and trends from 2011 to 2018 and factors associated with youth menthol and non-menthol smoking from 2016 to 2018.

METHODS

Using data from the 2011-2018 National Youth Tobacco Surveys, past 30-day (current) menthol and non-menthol cigarette smoking were estimated for all youth (prevalence) and youth smokers (proportions). Trends were examined using Joinpoint regression, calculating the annual percent change (APC). Multivariate logistic regression analyses identified factors associated with menthol smoking.

RESULTS

From 2011 to 2018, menthol cigarette smoking among current youth cigarette smokers significantly decreased from 57.3% to 45.7% (APC: -3.0%), while non-menthol (38.2% to 47.3% [APC: 2.9%]) and unknown menthol status (not sure\missing) (4.5% to 7.0% [APC: 7.1%]) significantly increased. Menthol cigarette smoking among high school, male, female, and non-Hispanic white current cigarette smokers decreased, but remained unchanged among middle school, non-Hispanic black, and Hispanic smokers. Significantly higher proportions of menthol cigarette smokers smoked on ≥20 days, ≥2 cigarettes per day, and ≥100 cigarettes in their lifetime compared to non-menthol smokers. Among current cigarette smokers, non-Hispanic blacks, Hispanics, flavored non-cigarette tobacco users, frequent smokers (≥20 days), those smoking 2-5 cigarettes per day, and those living with someone who uses tobacco had higher odds of menthol cigarette smoking.

CONCLUSIONS

In 2018, nearly half of current youth cigarette smokers smoked menthol cigarettes. While menthol cigarette smoking declined from 2011 to 2018 among all youth and among youth smokers, there was no change in menthol cigarette smoking among non-Hispanic black, Hispanic, and middle school cigarette smokers.

IMPLICATIONS

This study finds that overall cigarette and menthol cigarette smoking declined in youth from 2011 to 2018. However, menthol cigarette smoking among non-Hispanic black, Hispanic, and middle school youth cigarette smokers did not change. Information from this study can help inform efforts to reduce menthol cigarette smoking among US youth, particularly racial/ethnic minority populations.

Effects of Cigarette Prices on Intention to Quit, Quit Attempts, and Successful Cessation Among African American Smokers

INTRODUCTION

This study examined the effects of cigarette price on intention to quit, quit attempts, and successful cessation among African American smokers in the United States and explored whether price effects differed by income level and menthol use status. Price effects were further compared to White counterparts.

METHODS

We used pooled cross-sectional data from 2006 to 2007 and 2010 to 2011 Tobacco Use Supplements to the Current Population Survey to analyze 4213 African American recent active smokers. Three dependent variables were examined: any quit attempts in the past 12 months, successful cessation for at least 3 months, and intention to quit in the next 6 months. For each dependent variable, separate multiple logistic regression models were estimated to determine the impact of cigarette prices.

RESULTS

There was no indication that price was associated with quit attempts or successful cessation, but price was positively associated with increased odds of intending to quit among African American smokers (p < .001). In contrast, prices were positively associated with intention to quit and quit attempts for White smokers. The association between price and intention to quit was significantly positive for African American low-income and menthol smokers but was not statistically significant for African American high-income and non-menthol smokers. There was no evidence of a price effect on quit attempts and successful cessation for each subgroup of African Americans.

CONCLUSIONS

Tobacco tax policy alone may not be enough to increase quit attempts or successful cessation among African Americans. Community-based cessation programs tailored toward African American smokers, especially low-income menthol smokers, are needed.

IMPLICATIONS

The results revealed that, among African American smokers, particularly among low-income and menthol smoking African American smokers, price appears to be positively associated with intention to quit; nevertheless, this deterrent effect does not appear to translate to actualized quit attempts or successful cessation. Increasing cigarette prices as a standalone policy may not be independently effective in increasing quit attempts and successful cessation within the African American community. Community-based cessation interventions tailored for African Americans are needed to help further translate desired cessation into actualized quit attempts.

Impact of Menthol on Oral Nicotine Consumption in Female and Male Sprague Dawley Rats

INTRODUCTION

One of the preferable flavors in oral nicotine delivery systems is menthol which masks the harshness of tobacco. However, possible interactions between oral menthol and nicotine on intake and preference remain unclear. Therefore, we aimed to determine the impact of menthol on oral nicotine consumption.

METHODS

Adult Sprague Dawley female and male rats (n = 8 per group) were given a choice of water or drug solution by using two-bottle free choice paradigm for 2 weeks: vehicle (5% ethanol), nicotine (20 mg/L), menthol (1 g/L) and mentholated nicotine groups. At the end of the study, plasma nicotine levels were determined.

RESULTS

When rats were given a choice of nicotine or water, nicotine intake was similar between female and male rats. Menthol addition to nicotine solution significantly increased nicotine intake and preference in male but not female rats without a considerable effect on total fluid intake and body weight change in either sex. The average nicotine intake in male rats was 0.5 ± 0.05 and 1.4 ± 0.12 mg/kg/day for nicotine and menthol-nicotine combination (p < .05), respectively. The average nicotine intake in female rats was 0.6 ± 0.05 and 0.6 ± 0.03 mg/kg/day for nicotine and menthol-nicotine combination (p > .05), respectively. Plasma nicotine levels were not significantly different between the groups in either male (nicotine group: 20.8 ± 4.9, mentholated nicotine group: 31.9 ± 3.2 ng/mL) or female (nicotine group: 24.0 ± 3.3, mentholated nicotine group: 17.8 ± 2.9 ng/mL) rats (p > .05).

CONCLUSIONS

Menthol increases oral nicotine consumption in male, but not female, rats.

IMPLICATIONS

This study may provide data on the co-use of menthol and nicotine in smokeless tobacco, particularly oral dissolvable tobacco products.

Product Substitution After A Real-World Menthol Ban: A Cohort Study

Objectives

The province of Ontario, Canada banned menthol in cigarettes and other tobacco products effective January 1^st, 2017 adding to an existing flavour ban. However, all flavoured e-cigarettes, flavoured cigars larger than 6g, and alcohol flavoured cigars without filters over 1.4g were exempted. This paper examines the association between use of flavoured non-cigarette products and self-reported cigarette smoking cessation after the ban.

Methods

Current past-30 day cigarette smokers (N=913) who were 16 years or older, living in Ontario were recruited between September-December 2016 and re-contacted January-August 2018.

Results

Both daily and occasional pre-ban menthol cigarette smokers were more likely to use flavoured cigar products (adjusted relative rate, RR=1.53, 95% confidence interval, CI=1.01, 2.31; adjusted RR=1.57, 95% CI=1.06, 2.30) after the ban, while occasional pre-ban menthol cigarette smokers were more likely to use other tobacco products (adjusted RR=1.25, 95% CI=1.02, 1.53) or flavoured other tobacco products (adjusted RR=1.56, 95% CI=1.09, 2.24), conditional on prior use.

Conclusions

Menthol smokers prior to the ban were more likely to use other tobacco products, or flavoured tobacco products, after the ban. These results suggest that comprehensive menthol bans could be more effective without the option of using flavoured tobacco or nicotine products as substitutes.

Adolescent menthol cigarette use and risk of nicotine dependence: Findings from the national Population Assessment on Tobacco and Health (PATH) study

BACKGROUND

Menthol cigarettes appeal to adolescents because they mask the harsh taste and sensation of tobacco smoke thereby making it easier to inhale the smoke. As a result, menthol cigarette users expose themselves to higher levels of nicotine relative to non-menthol cigarettes and increase their risk for developing nicotine dependence. We examined whether adolescent menthol smokers (vs. non-menthol smokers) reported higher nicotine dependence.

METHODS

Data were from adolescent past 30-day cigarette smokers participating in Wave 2 of the Population Assessment of Tobacco and Health survey (n = 434). Nicotine dependence was assessed using eight items from the Wisconsin Inventory of Smoking Dependence Motives corresponding to individual subscale constructs. Linear regression models evaluated the association of past 30-day menthol (vs. non-menthol) cigarette use with each dependence outcome in separate models, adjusting for age, gender, race, and other tobacco product use.

RESULTS

49.5% of past 30-day youth cigarette smokers reported smoking menthol cigarettes. In adjusted models, menthol smokers (vs. non-menthol smokers) reported significantly higher nicotine dependence for three constructs: craving (p = 0.005), affiliative attachment (p = 0.005), and tolerance (p = 0.003). No differences for menthol vs. non-menthol smokers were observed for loss of control, negative reinforcement, cognitive enhancement, automaticity, or social environment after correction for multiple comparisons.

CONCLUSIONS

Findings suggest that menthol cigarette smokers are not just more physically dependent on nicotine but also experience increased emotional attachments to cigarettes compared to their non-menthol smoking peers. Because adolescents are vulnerable to developing nicotine dependence, tobacco control policies that restrict youth access to menthol cigarettes are urgently needed.

Dependence, plans to quit, quitting self-efficacy and past cessation behaviours among menthol and other flavoured cigarette users in Europe: The EUREST-PLUS ITC Europe Surveys

INTRODUCTION

This study characterises smoking and cessation-related behaviours among menthol and other flavoured cigarette users in Europe prior to the implementation of the European Tobacco Products Directive (TPD) ban on the sale of flavoured cigarettes.

METHODS

An analysis of cross-sectional data from the 2016 EUREST-PLUS ITC Europe Surveys was conducted among a sample of 10760 adult smokers from eight European Union Member States. Respondents were classified as menthol, other flavoured, unflavoured, or no usual flavour cigarette users and compared on smoking and cessation behaviours and characteristics. Data were analysed in SPSS Complex Samples Package using bivariate and multivariate regression analyses adjusted for sociodemographic characteristics, dependence, and country.

RESULTS

In bivariate analyses, cigarette flavour was significantly associated with all outcomes (p<0.001). After adjusting for sociodemographic characteristics, these associations attenuated but remained significant and in the same direction for dependence, self-efficacy, plans to quit, past quit attempts, and ever e-cigarette use. In fully adjusted models, compared to smokers of non-flavoured cigarettes, menthol smokers were less likely to smoke daily (AOR=0.47, 95% CI: 0.32-0.71), smoke within 30 min of waking (0.52,0.43-0.64), consider themselves addicted (0.74,0.59-0.94), and more likely to have ever used e-cigarettes (1.26,1.00-1.57); other flavoured cigarette smokers were less likely to smoke daily (0.33,0.15-0.77), and have higher self-efficacy (1.82,1.20-2.77); no usual flavour smokers were less likely to smoke daily (0.34,0.22-0.51), smoke within 30 min of waking (0.66,0.55-0.80), consider themselves addicted (0.65,0.52-0.78), have ever made a quit attempt (0.69,0.58-0.84), have ever used e-cigarettes (0.66,0.54-0.82), and had higher self-efficacy (1.46,1.19-1.80).

CONCLUSIONS

Smokers of different cigarette flavours in Europe differ on smoking and cessation characteristics. The lower dependence of menthol cigarette smokers could lead to greater success rates if quit attempts are made, however cross-country differences in smoking behaviours and quitting intentions could lead to the TPD ban on cigarette flavours having differential impact if not accompanied by additional measures, such as smoking cessation support.

Influence of the E-Cigarette Emission Profile by the Ratio of Glycerol to Propylene Glycol in E-Liquid Composition

The use of electronic cigarettes (E-cig) is popular because of the perception that they are less addictive and safer compared to the traditional cigarettes. Nevertheless, there are still harmful effects associated with chemicals emitted from E-cig. Identifying the sources of the emitted compounds can be challenging because of the differences in the design of E-cig devices and the variability in the composition of E-cig liquids used in these devices. In this study, the emission profiles from impurity-free E-liquids containing only propylene glycol and glycerol in various percentage ratios along with two commercially available E-liquids were evaluated using gas chromatography-mass spectrometry (GC-MS). This study approach allows the elucidation of the transformation pathways of the major emitted compounds without the confounding effects of existing impurities or flavor ingredients added to E-liquids. Analysis of the vapor phases of E-cig emissions detected toxicants such as acetaldehyde, acrolein, benzaldehyde, as well as benzene, toluene, ethylbenzene, and xylene (BTEX) compounds. The amount of glycerol in the E-liquids has a major effect on the concentration of these hazardous compounds emitted because the concentration of these chemicals increased with increasing glycerol percentage in the E-liquid. Acetaldehyde and acrolein increased by 175-fold and 28-fold, respectively, when the glycerol composition was increased from 0 to 80%. Benzaldehyde, naphthalene, diphenyl ether, and glycerol along with menthol and nicotine that were present in the commercial E-liquids were also detected in the aerosol condensates. The cascade impactor data on the distribution of the nicotine and menthol in different size fractions from >2.5 to <2.5 μm allow the estimates of the extent of toxicant deposition in different parts of the pulmonary system including the oropharynx region, the trachea as well as inside the alveoli and bronchioles. In summary, users of E-cig are exposed to harmful chemicals even if the E-liquids contain only propylene glycol and glycerol without flavorings, nicotine, or impurities. Furthermore, this study shows that E-liquids containing higher percentages of glycerol will produce higher levels of toxicants compared to E-liquids with similar percentages of propylene glycol. This finding has important implications to E-cigarette vendors and manufacturers, consumers, and regulatory agencies.

Ban on menthol-flavoured tobacco products predicts cigarette cessation at 1 year: a population cohort study

OBJECTIVES

The province of Ontario, Canada, banned the use of menthol-flavoured tobacco products as of 1 January 2017. The long-term impact of a menthol ban on smoking behaviour has not been previously evaluated.

METHODS

Population cohort study with baseline survey conducted September-December 2016 and follow-up January-August 2018 among residents of Ontario, Canada, 16 years old and over who reported current smoking (past 30 days) at baseline survey and completed follow-up (n=913) including 187 reporting smoking menthol cigarettes daily, 420 reported smoking menthol cigarettes occasionally, and 306 were non-menthol cigarette smokers. Relative rates of making a quit attempt and being a non-smoker at follow-up were estimated with Poisson regression controlling for smoking and demographic characteristics at baseline.

RESULTS

At follow-up, 63% of daily menthol smokers reported making a quit attempt since the ban compared with 62% of occasional menthol smokers and 43% of non-menthol smokers (adjusted relative rate (ARR) for daily menthol smokers compared with non-menthol smokers: 1.25; 95% CI 1.03 to 1.50). At follow-up, 24% of daily menthol smokers reported making a quit since the ban compared with 20% of occasional menthol smokers and 14% of non-menthol smokers (ARR for daily menthol smokers compared with non-menthol smokers: 1.62; 95% CI 1.08 to 2.42).

CONCLUSIONS

The study found higher rates of quitting among daily and occasional menthol smokers in Ontario 1 year after the implementation of a menthol ban compared with non-menthol smokers. Our findings suggest that restrictions on menthol may lead to substantial improvements in public health.

Compliance with the City of Chicago's partial ban on menthol cigarette sales

INTRODUCTION

In the USA, menthol cigarettes are associated with smoking initiation and decreased likelihood of cessation, particularly for low-income and non-White populations. Local ordinances to restrict menthol cigarette sales are an emergent policy option. In July 2016, Chicago, Illinois became the first major US city to ban menthol cigarette sales within 500 feet of schools. This study assessed ban compliance in June 2017.

METHODS

We randomly selected 100 of 154 stores within 500 feet of a high school. Ninety stores were included in the analysis, excluding permanently closed stores or stores that did not sell tobacco prior to the ban. Compliance was determined by whether a menthol cigarette pack was purchased. We also assessed presence of menthol cigarette replacement packs. Multivariable logistic regression modelled compliance by store type, school (distance to high school, school type) and neighbourhood-level factors (poverty level, proportion of non-White residents).

RESULTS

Compliance rate was 57% (weighted, n=53) and no replacement packs were observed. Non-compliant stores were more likely to advertise menthol cigarettes, but ads were present in eight compliant stores. Gas stations had 81% lower odds (OR=0.19, 95% CI 0.06 to 0.58) of complying with the menthol cigarette ban compared with larger/chain stores. School-level and neighbourhood factors were not associated with compliance.

DISCUSSION

The poor compliance observed with Chicago's partial menthol cigarette ban highlights the need for comprehensive efforts. Optimising local resources to target enforcement efforts in gas stations could improve compliance. Ordinances that also restrict advertising could potentially enhance ban impact by reducing exposure to product and promotions.

The Association of Menthol Cigarette Use With Quit Attempts, Successful Cessation, and Intention to Quit Across Racial/Ethnic Groups in the United States

Introduction

Few studies have examined the relationship between menthol use and smoking cessation across various racial/ethnic groups; the findings were mixed. This study explored the association of menthol cigarette use with quit attempts, smoking cessation, and intention-to-quit among US adults and by race/ethnicity.

Methods

Using the 2006/2007 and 2010/2011 Tobacco Use Supplements to the Current Population Survey data, this study analyzed 54 448 recent active smokers, defined as current smokers or former smokers who quit less than 12 months ago. Three behaviors were examined: any quit attempts in the past 12 months, successful cessation for ≥3 months, and intention-to-quit smoking in the next 6 months. For each cessation behavior, multiple logistic regression models were estimated separately for the full-sample and stratified racial/ethnic subsamples.

Results

While 72.3% of African American recent active smokers typically smoked menthol cigarettes, this proportion was 21.7%, 21.5%, and 28.0% for whites, Asians, and Hispanics, respectively. African American menthol smokers had higher odds of quit attempts compared to non-African American, non-menthol smokers (full-sample analysis), as well as African American non-menthol smokers (subsample analysis). Menthol use was not significantly associated with quit attempts in other racial/ethnic subsamples. There was no significant difference in either successful cessation or intention-to-quit between menthol and non-menthol smokers.

Conclusions

African American menthol smokers were more likely to attempt to quit smoking than non-menthol smokers but these quit attempts did not translate into successful cessation. This study revealed no association of menthol use with quit attempts, successful cessation, and intention-to-quit among other racial/ethnic groups.

Implications

The findings suggested that African American menthol smokers were more motivated to quit smoking; yet, the results also indicated no significant differences in successful cessation between African American menthol and non-menthol smokers. Interventions targeting menthol smokers within the African American community may help bridge this gap. While more local sales restrictions are beginning to occur (eg, Tobacco 21 efforts), additional policies restricting price discounting as well as the regulation of access to and the time, place, and/or manner of menthol tobacco advertising could also improve cessation rates. Further evaluation is needed to determine the viability of these policies.

Menthol cigarette smoking among individuals in treatment for substance use disorders

There are higher rates of menthol cigarette smoking within certain population subgroups. Limited research has examined menthol use among individuals in treatment for substance use disorders (SUD), a population with a high prevalence of cigarette smoking, poor smoking cessation outcomes, and high tobacco disease burden. Survey data were collected from 863 smokers sampled from 24 SUD treatment programs affiliated with the NIDA Clinical Trials Network (CTN) in the United States. Prevalence of menthol cigarette smoking was examined for the sample. Bivariate and multivariate analyses were used to examine demographic and tobacco use characteristics associated with menthol cigarette smoking. Overall, the prevalence of menthol smoking among individuals in SUD treatment was 53.3%. Smoking menthol versus non-menthol cigarettes was associated with being female (AOR=1.61, p=0.003), African American (AOR=7.89, p<0.001), Hispanic/Latino (AOR=3.39, p<0.001), and lower odds of having a college degree (AOR=0.49, p=0.015). Controlling for demographic factors, menthol smokers were more likely to report marijuana (AOR=3.33, p<0.007) as their primary drug compared to alcohol. Lastly, menthol smokers were more likely to report interest in getting help for quitting smoking (AOR=1.53, p=0.01), although they were not more likely to report making a past year quit attempt. In conclusion, use of menthol cigarettes was higher among smokers in SUD treatment than in general population smokers. Regulatory policies targeting the manufacture, marketing, or sale of menthol cigarettes may benefit vulnerable populations, including smokers in SUD treatment.

Comparison of a preferred versus non-preferred waterpipe tobacco flavour: subjective experience, smoking behaviour and toxicant exposure

INTRODUCTION

One possible reason for the rapid proliferation of waterpipe (WP) smoking is the pervasive use of flavoured WP tobacco. To begin to understand the impact of WP tobacco flavours, the current study examined the impact of a preferred WP tobacco flavour compared with a non-preferred tobacco flavoured control on user's smoking behaviour, toxicant exposure and subjective smoking experience.

METHOD

Thirty-six current WP smokers completed two, 45-minute ad libitum smoking sessions (preferred flavour vs non-preferred tobacco flavour control) in a randomised cross-over design. Participants completed survey questionnaires assessing subjective smoking experience, exhaled carbon monoxide (eCO) testing, and provided blood samples for monitoring plasma nicotine. WP smoking topography was measured continuously throughout the smoking session.

RESULTS

While participants reported an enhanced subjective smoking experience including greater interest in continued use, greater pleasure derived from smoking, increased liking and enjoyment, and willingness to continue use after smoking their preferred WP tobacco flavour (p values <0.05), no significant differences were observed in nicotine and carbon monoxide boost between flavour preparations. Greater average puff volume (p=0.018) was observed during the non-preferred flavour session. While not significant, measures of flow rate, interpuff interval (IPI), and total number of puffs were trending towards significance (p values <0.10), with decreased IPI and greater total number of puffs during the preferred flavour session.

DISCUSSION

The current study is the first to examine flavours in WP smoking by measuring preferred versus control preparations to understand the impact on subjective experience, smoking behaviour and toxicant exposure. The pattern of results suggests that even this relatively minor manipulation resulted in significant changes in subjective experience. These results indicate a possible need for regulations restricting flavours in WP tobacco as with combustible cigarettes.

Regulating Cannabis Manufacturing: Applying Public Health Best Practices from Tobacco Control

State legalization and regulation of cannabis, despite continued federal illegality, is a massive shift in regulatory approach. Manufactured cannabis, including concentrates, extracts, edibles, tinctures, topicals and other products, has received less attention than more commonly used dried flower, but represents emerging regulatory challenges due to additives, potency, consumption methods, and abuse and misuse potential. In November 2017, the California Department of Public Health (CDPH) released initial cannabis manufacturing regulations as part of a new state regulatory structure. As the largest U.S. medical cannabis market (and largest legal adult use market in the world beginning in 2018), California's regulatory approach will potentially influence national and global policy. Comparing CDPH's initial regulations to tobacco control best practices reveals that, while the regulations recognize the need to protect public health, prioritizing public health over business interests requires stronger approaches to labeling, packaging, and product formulations. Based on tobacco best practices, we recommend that cannabis regulations incorporate large and proportionately sized informational labels, a prominent universal cannabis symbol, rotating and pictorial health warnings, mandatory plain packaging, a comprehensive ban on characterizing flavors and addictive additives, and strict limits on the potency of inhalable products and those easily confused with non-cannabis products.

Menthol cigarettes and the public health standard: a systematic review

Background

Although menthol was not banned under the Tobacco Control Act, the law made it clear that this did not prevent the Food and Drug Administration from issuing a product standard to ban menthol to protect public health. The purpose of this review was to update the evidence synthesis regarding the role of menthol in initiation, dependence and cessation.

Methods

A systematic review of the peer-reviewed literature on menthol cigarettes via a PubMed search through May 9, 2017. The National Cancer Institute’s Bibliography of Literature on Menthol and Tobacco and the FDA’s 2011 report and 2013 addendum were reviewed for additional publications. Included articles addressing initiation, dependence, and cessation were synthesized based on study design and quality, consistency of evidence across populations and over time, coherence of findings across studies, and plausibility of the findings.

Results

Eighty-two studies on menthol cigarette initiation (n = 46), dependence (n = 14), and cessation (n = 34) were included. Large, representative studies show an association between menthol and youth smoking that is consistent in magnitude and direction. One longitudinal and eight cross-sectional studies demonstrate that menthol smokers report increased nicotine dependence compared to non-menthol smokers. Ten studies support the temporal relationship between menthol and reduced smoking cessation, as they measure cessation success at follow-up.

Conclusions

The strength and consistency of the associations in these studies support that the removal of menthol from cigarettes is likely to reduce youth smoking initiation, improve smoking cessation outcomes in adult smokers, and in turn, benefit public health.

Electronic supplementary material

The online version of this article (10.1186/s12889-017-4987-z) contains supplementary material, which is available to authorized users.

Impact of Menthol Smoking on Nicotine Dependence for Diverse Racial/Ethnic Groups of Daily Smokers

Introduction: The aims of this study were to evaluate whether menthol smoking and race/ethnicity are associated with nicotine dependence in daily smokers. Methods: The study used two subsamples of U.S. daily smokers who responded to the 2010–2011 Tobacco Use Supplement to the Current Population Survey. The larger subsample consisted of 18,849 non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic (HISP) smokers. The smaller subsample consisted of 1112 non-Hispanic American Indian/Alaska Native (AIAN), non-Hispanic Asian (ASIAN), non-Hispanic Hawaiian/Pacific Islander (HPI), and non-Hispanic Multiracial (MULT) smokers. Results: For larger (smaller) groups the rates were 45% (33%) for heavy smoking (16+ cig/day), 59% (51%) for smoking within 30 min of awakening (Sw30), and 14% (14%) for night-smoking. Overall, the highest prevalence of menthol smoking corresponded to NHB and HPI (≥65%), followed by MULT and HISP (31%–37%), and then by AIAN, NHW, and ASIAN (22%–27%) smokers. For larger racial/ethnic groups, menthol smoking was negatively associated with heavy smoking, not associated with Sw30, and positively associated with night-smoking. For smaller groups, menthol smoking was not associated with any measure, but the rates of heavy smoking, Sw30, and night-smoking varied across the groups. Conclusions: The diverse associations between menthol smoking and nicotine dependence maybe due to distinction among the nicotine dependence measures, i.e., individually, each measure assesses a specific smoking behavior. Menthol smoking may be associated with promoting smoking behaviors.

Menthol Smokers: Metabolomic Profiling and Smoking Behavior

BACKGROUND

The use of menthol in cigarettes and marketing is under consideration for regulation by the FDA. However, the effects of menthol on smoking behavior and carcinogen exposure have been inconclusive. We previously reported metabolomic profiling for cigarette smokers, and novelly identified a menthol-glucuronide (MG) as the most significant metabolite directly related to smoking. Here, MG is studied in relation to smoking behavior and metabolomic profiles.

METHODS

This is a cross-sectional study of 105 smokers who smoked two cigarettes in the laboratory one hour apart. Blood nicotine, MG, and exhaled carbon monoxide (CO) boosts were determined (the difference before and after smoking). Spearman correlation, χ2, and ANCOVA adjusted for gender, race, and cotinine levels for menthol smokers assessed the relationship of MG boost, smoking behavior, and metabolic profiles. Multivariate metabolite characterization using supervised partial least squares-discriminant analysis (PLS-DA) was carried out for the classification of metabolomics profiles.

RESULTS

MG boost was positively correlated with CO boost, nicotine boost, average puff volume, puff duration, and total smoke exposure. Classification using PLS-DA, MG was the top metabolite discriminating metabolome of menthol versus nonmenthol smokers. Among menthol smokers, 42 metabolites were significantly correlated with MG boost, which linked to cellular functions, such as of cell death, survival, and movement.

CONCLUSIONS

Plasma MG boost is a new smoking behavior biomarker that may provide novel information over self-reported use of menthol cigarettes by integrating different smoking measures for understanding smoking behavior and harm of menthol cigarettes.

IMPACT

These results provide insight into the biological effect of menthol smoking. Cancer Epidemiol Biomarkers Prev; 26(1); 51-60. ©2016 AACR.

An Inventory of Methods for the Assessment of Additive Increased Addictiveness of Tobacco Products

BACKGROUND

Cigarettes and other forms of tobacco contain the addictive drug nicotine. Other components, either naturally occurring in tobacco or additives that are intentionally added during the manufacturing process, may add to the addictiveness of tobacco products. As such, these components can make cigarette smokers more easily and heavily dependent.Efforts to regulate tobacco product dependence are emerging globally. Additives that increase tobacco dependence will be prohibited under the new European Tobacco Product Directive.

OBJECTIVE

This article provides guidelines and recommendations for developing a regulatory strategy for assessment of increase in tobacco dependence due to additives. Relevant scientific literature is summarized and criteria and experimental studies that can define increased dependence of tobacco products are described.

CONCLUSIONS

Natural tobacco smoke is a very complex matrix of components, therefore analysis of the contribution of an additive or a combination of additives to the level of dependence on this product is challenging. We propose to combine different type of studies analyzing overall tobacco product dependence potential and the functioning of additives in relation to nicotine. By using a combination of techniques, changes associated with nicotine dependence such as behavioral, physiological, and neurochemical alterations can be examined to provide sufficient information.Research needs and knowledge gaps will be discussed and recommendations will be made to translate current knowledge into legislation. As such, this article aids in implementation of the Tobacco Product Directive, as well as help enable regulators and researchers worldwide to develop standards to reduce dependence on tobacco products.

IMPLICATIONS

This article provides an overall view on how to assess tobacco product constituents for their potential contribution to use and dependence. It provides guidelines that help enable regulators worldwide to develop standards to reduce dependence on tobacco products and guide researches to set research priorities on this topic.

Smoking Trends and Disparities Among Black and Non-Hispanic Whites in California

OBJECTIVES

The current study examined disparities in smoking trends across Blacks and non-Hispanic Whites in California.

METHODS

Data from the 1996 to 2008 California Tobacco Survey were analyzed to examine trends in smoking behaviors and cessation across Blacks and non-Hispanic Whites.

RESULTS

A decrease in overall ever and current smoking was observed for both Black and non-Hispanic Whites across the 12-year time period. A striking decrease in proportions of heavy daily smokers for both Black and non-Hispanic Whites were observed. Proportions of light and intermittent smokers and moderate daily smokers displayed modest increases for Blacks, but large increases for non-Hispanic Whites. Increases in successful cessation were also observed for Blacks and, to a lesser extent, for non-Hispanic Whites.

DISCUSSION

Smoking behavior and cessation trends across Blacks and non-Hispanic Whites were revealing. The decline in heavy daily and former smokers may demonstrate the success and effectiveness of tobacco control efforts in California. However, the increase in proportions of light and intermittent smokers and moderate daily smokers for both Blacks and non-Hispanic Whites demonstrates a need for tobacco cessation efforts focused on lighter smokers.

The tobacco endgame: a qualitative review and synthesis

The tobacco endgame concept reorients discussion away from the persistent control of tobacco toward plans for ending the tobacco epidemic, and envisions a tobacco-free future. A variety of policy approaches have been proposed, with many offered prior to the introduction of the unifying term ‘endgame’. We conducted a qualitative synthesis of the literature on tobacco control endgames, and drew on media accounts and discussion of analogous ideas for illustrative purposes. We identified proposals focused on the product, user, market/supply or larger institutional structures. Research on public support for these proposals was limited, but suggestive of some public appetite for endgame ideas. Advocates should be encouraged to explore new policy options and consider the goal of a tobacco-free future.

Menthol cigarette smoking among lesbian, gay, bisexual, and transgender adults

BACKGROUND

Menthol can mask the harshness and taste of tobacco, making menthol cigarettes easier to use and increasing their appeal among vulnerable populations. The tobacco industry has targeted youth, women, and racial minorities with menthol cigarettes, and these groups smoke menthol cigarettes at higher rates. The tobacco industry has also targeted the lesbian, gay, bisexual, and transgender (LGBT) communities with tobacco product marketing.

PURPOSE

To assess current menthol cigarette smoking by sexual orientation among a nationally representative sample of U.S. adults.

METHODS

Data were obtained from the 2009-2010 National Adult Tobacco Survey, a national landline and cellular telephone survey of non-institutionalized U.S. adults aged ≥18 years, to compare current menthol cigarette smoking between LGBT (n=2,431) and heterosexual/straight (n=110,841) adults. Data were analyzed during January-April 2014 using descriptive statistics and logistic regression adjusted for sex, age, race, and educational attainment.

RESULTS

Among all current cigarette smokers, 29.6% reported usually smoking menthol cigarettes in the past 30 days. Menthol use was significantly higher among LGBT smokers, with 36.3% reporting that the cigarettes they usually smoked were menthol compared to 29.3% of heterosexual/straight smokers (p<0.05); this difference was particularly prominent among LGBT females (42.9%) compared to heterosexual/straight women (32.4%) (p<0.05). Following adjustment, LGBT smokers had greater odds of usually smoking menthol cigarettes than heterosexual/straight smokers (OR=1.31, 95% CI=1.09, 1.57).

CONCLUSIONS

These findings suggest that efforts to reduce menthol cigarette use may have the potential to reduce tobacco use and tobacco-related disease and death among LGBT adults.

Neuroanatomical circuitry mediating the sensory impact of nicotine in the central nervous system

Direct actions of nicotine in the CNS appear to be essential for its reinforcing properties. However, activation of nicotinic acetylcholine receptors (nAChRs) on afferent sensory nerve fibers is an important component of addiction to, and withdrawal from, cigarette smoking. The aim of the present study was to identify the neuroanatomical substrates activated by the peripheral actions of nicotine and to determine whether these sites overlap brain structures stimulated by direct actions of nicotine. Mouse brains were examined by immunohistochemistry for c-Fos protein after intraperitoneal injection of either nicotine hydrogen tartrate salt (NIC; 30 and 40 μg/kg) or nicotine pyrrolidine methiodide (NIC-PM; 20 and 30 μg/kg). NIC-PM induced c-Fos immunoreactivity (IR) at multiple brain sites. In the brainstem, c-Fos IR was detected in the locus coeruleus, laterodorsal tegmental nucleus, and pedunculotegmental nucleus. In the midbrain, c-Fos IR was observed in areas overlapping the ventral tegmental area (VTA), which includes the paranigral nucleus, parainterfascicular nucleus, parabrachial pigmental area, and rostral VTA. Other structures of the nicotine brain-reward circuitry activated by NIC-PM included the hypothalamus, paraventricular thalamic nucleus, lateral habenular nucleus, hippocampus, amygdala, accumbens nucleus, piriform cortex, angular insular cortex, anterior olfactory nucleus, lateral septal nucleus, bed nucleus of stria terminalis, cingulate and medial prefrontal cortex, olfactory tubercle, and medial and lateral orbital cortex. NIC, acting through central and peripheral nAChRs, produced c-Fos IR in areas that overlapped NIC-PM-induced c-Fos-expressing sites. These neuroanatomical data are the first to demonstrate that the CNS structures that are the direct targets of nicotine are also anatomical substrates for the peripheral sensory impact of nicotine.

The debate on regulating menthol cigarettes: closing a dangerous loophole vs freedom of choice

The Family Smoking Prevention and Tobacco Control Act exempted menthol from a flavoring additive ban, tasking the Tobacco Products Safety Advisory Committee to advise on the scientific evidence on menthol. To inform future tobacco control efforts, we examined the public debate from 2008 to 2011 over the exemption. Health advocates regularly warned of menthol's public health damages, but inconsistently invoked the health disparities borne by African American smokers. Tobacco industry spokespeople insisted that making menthol available put them on the side of African Americans' struggle for justice and enlisted civil rights groups to help them make that case. In future debates, public health must prioritize and invest in the leadership of communities most affected by health harms to ensure a strong, unrelenting voice in support of health equity.

Menthol cigarette use predicts treatment outcomes of weight-concerned smokers

BACKGROUND

Studies have shown that individuals who smoke menthol cigarettes are less likely to quit smoking and more likely to relapse during a quit attempt. The current study investigated menthol cigarette use as a potential predictor of smoking cessation outcomes in a sample of treatment-seeking smokers.

METHODS

This is a secondary analysis of data from a randomized controlled trial of low-dose naltrexone augmentation of nicotine replacement designed to examine smoking cessation and postcessation weight gain in weight-concerned smokers.

RESULTS

Analyses revealed that menthol use predicted lower quit rates. Among menthol smokers (N = 61), 13% were abstinent at week 26, and among nonmenthol smokers (N = 105), 30% were abstinent (Wald = 4.15, p = .04; odds ratio [OR] = 2.47; 95% CI = 1.04-5.90). Further, menthol smokers who quit smoking gained significantly more weight at week 26 (M = 14.87 lbs, SD = 9.08; t(37) = -2.22, p = .03) than nonmenthol smokers who quit (M = 7.95 lbs, SD = 7.53).

CONCLUSIONS

Menthol cigarette use has not typically been evaluated as a predictor of smoking cessation outcomes, but emerging evidence suggests that consumption of menthol may make cessation more difficult. This study adds to the literature supporting the claim that smoking menthol cigarettes can have adverse effects on smoking cessation efforts and on other cessation-related outcomes, such as postcessation weight gain.

The toxic effects of cigarette additives. Philip Morris' project mix reconsidered: an analysis of documents released through litigation

BACKGROUND

In 2009, the promulgation of US Food and Drug Administration (FDA) tobacco regulation focused attention on cigarette flavor additives. The tobacco industry had prepared for this eventuality by initiating a research program focusing on additive toxicity. The objective of this study was to analyze Philip Morris' Project MIX as a case study of tobacco industry scientific research being positioned strategically to prevent anticipated tobacco control regulations.

METHODS AND FINDINGS

We analyzed previously secret tobacco industry documents to identify internal strategies for research on cigarette additives and reanalyzed tobacco industry peer-reviewed published results of this research. We focused on the key group of studies conducted by Phillip Morris in a coordinated effort known as "Project MIX." Documents showed that Project MIX subsumed the study of various combinations of 333 cigarette additives. In addition to multiple internal reports, this work also led to four peer-reviewed publications (published in 2001). These papers concluded that there was no evidence of substantial toxicity attributable to the cigarette additives studied. Internal documents revealed post hoc changes in analytical protocols after initial statistical findings indicated an additive-associated increase in cigarette toxicity as well as increased total particulate matter (TPM) concentrations in additive-modified cigarette smoke. By expressing the data adjusted by TPM concentration, the published papers obscured this underlying toxicity and particulate increase. The animal toxicology results were based on a small number of rats in each experiment, raising the possibility that the failure to detect statistically significant changes in the end points was due to underpowering the experiments rather than lack of a real effect.

CONCLUSION

The case study of Project MIX shows tobacco industry scientific research on the use of cigarette additives cannot be taken at face value. The results demonstrate that toxins in cigarette smoke increase substantially when additives are put in cigarettes, including the level of TPM. In particular, regulatory authorities, including the FDA and similar agencies elsewhere, could use the Project MIX data to eliminate the use of these 333 additives (including menthol) from cigarettes.

Menthol: putting the pieces together

Objective

To integrate information on cigarette companies' understanding and use of menthol as summarised in published research based on previously internal tobacco industry documents with results from large population-based surveys of tobacco use and other independent sources.

Data sources

Papers published in this supplement of Tobacco Control, together with papers identified using PubMed searches.

Results

Tobacco companies shaped consumer perceptions of menthol cigarettes. Menthol is not just a flavouring agent. Cigarette companies use menthol's ability to mask irritation and provide sensory effects to make menthol cigarettes appeal to youth and health-concerned smokers, in part because menthol makes low-tar cigarettes more palatable. Consistent with targeted marketing, youths, women and African Americans disproportionately smoke menthols. There appear to be complex interactions with addictive effects of nicotine. The ubiquitous addition of menthol by tobacco companies to over 90% of all tobacco products, whether labelled ‘menthol’ or not, demonstrates that menthol is not simply a flavour or brand. Menthol imparts sensory characteristics to cigarettes and has a complex interaction with nicotine that affects smoking behaviour whether it is perceived or not, or whether cigarettes containing menthol are marketed as ‘menthol’ or not. Adding menthol increases fine particles in cigarette smoke, which have immediate adverse effects on the risk of heart attack.

Conclusion

Information from industry documents, confirmed by independent scientific literature, consistently demonstrates that menthol increases population harm from smoking by increasing initiation and reducing cessation in some groups. Menthol facilitates and increases smoking, which causes disease and death.

Direct disease-inducing effects of menthol through the eyes of tobacco companies

OBJECTIVE

Menthol is an important additive in most tobacco products and is an identifying characteristic of many brands. We assessed tobacco companies' research on direct disease-inducing effects of menthol and menthol cigarettes.

METHODS

A search was conducted among documents included in the Legacy Tobacco Documents Library. Relevant documents addressed subject areas such as pharmacology, short-term and long-term effects and biomarkers of smoking exposure.

RESULTS

The documents contain little internal industry research on the disease-inducing effects of menthol. Most information in the tobacco industry documents are reviews of the published biomedical literature, from which the companies concluded that menthol did not have any direct disease-inducing effects. Evidence that contradicted this conclusion was downplayed. Except for one study, there was no evidence of the companies following up on positive findings in the literature with their own studies. In one case, results were presented at a public scientific meeting concluding that 'There were no effects from addition of menthol to test or reference cigarettes', when a company's internal pathology analysis contradicted this statement.

CONCLUSION

The available industry documents suggest that tobacco companies conducted little research on the potential disease-inducing effects of menthol and did not pursue studies that suggested adverse effects.

Menthol's potential effects on nicotine dependence: a tobacco industry perspective

OBJECTIVE

To examine what the tobacco industry knows about the potential effects menthol may have on nicotine dependence.

METHODS

A snowball strategy was used to systematically search the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu/) between 22 February and 29 April, 2010. Of the approximately 11 million documents available in the Legacy Tobacco Documents Library, the iterative searches returned tens of thousands of results. We qualitatively analysed a final collection of 309 documents relevant the effects of menthol on nicotine dependence.

RESULTS

The tobacco industry knows that menthol overrides the harsh taste of tobacco and alleviates nicotine's irritating effects, synergistically interacts with nicotine, stimulates the trigeminal nerve to elicit a 'liking' response for a tobacco product, and makes low tar, low nicotine tobacco products more acceptable to smokers than non-mentholated low delivery products.

CONCLUSION

Menthol is not only used in cigarettes as a flavour additive; tobacco companies know that menthol also has sensory effects and interacts with nicotine to produce tobacco products that are easier to smoke, thereby making it easier to expose smokers, especially those who are new and uninitiated, to the addictive power of nicotine.

Menthol sensory qualities and smoking topography: a review of tobacco industry documents

OBJECTIVE

To determine what the tobacco industry knew about the potential effects of menthol on smoking topography-how a person smokes a cigarette.

METHODS

A snowball strategy was used to systematically search the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu) between 1 June 2010 and 9 August 2010. We qualitatively analysed a final collection of 252 documents related to menthol and smoking topography.

RESULTS

The tobacco industry knew that menthol has cooling, anaesthetic and analgesic properties that moderate the harshness and irritation of tobacco. Owing to its physiological effects, menthol contributes to the sensory qualities of the smoke and affects smoking topography and cigarette preference.

CONCLUSION

Our review of industry studies suggests that the amount of menthol in a cigarette is associated with how the cigarette is smoked and how satisfying it is to the smoker. If menthol in cigarettes was banned, as the US Food and Drug Administration (FDA) is currently considering, new/experimental smokers might choose not to smoke rather than experience the harshness of tobacco smoke and the irritating qualities of nicotine. Similarly, established menthol smokers might choose to quit if faced with an unpleasant smoking alternative.

Tobacco documents research methodology

Tobacco documents research has developed into a thriving academic enterprise since its inception in 1995. The technology supporting tobacco documents archiving, searching and retrieval has improved greatly since that time, and consequently tobacco documents researchers have considerably more access to resources than was the case when researchers had to travel to physical archives and/or electronically search poorly and incompletely indexed documents. The authors of the papers presented in this supplement all followed the same basic research methodology. Rather than leave the reader of the supplement to read the same discussion of methods in each individual paper, presented here is an overview of the methods all authors followed. In the individual articles that follow in this supplement, the authors present the additional methodological information specific to their topics. This brief discussion also highlights technological capabilities in the Legacy Tobacco Documents Library and updates methods for organising internal tobacco documents data and findings.