Menthol Cigarettes and Smoking Cessation among Adult Smokers in the US

Abstract

Objectives:

To identify differences in cessation, nicotine dependence and quit attempts between smokers using non-menthol cigarettes and smokers using menthol cigarettes differing in menthol delivery method (eg, menthol in the tobacco only, crushable capsules only or both).

Methods:

Data from the Population Assessment of Tobacco and Health Study, Waves 1 and 2 (W1 and W2), were analyzed to determine associations of delivery method of menthol with cessation, nicotine dependence, and quit attempts among current adult cigarette smokers.

Results:

Nearly 40% of US smokers reported using a mentholated cigarette product with most using a product mentholated in the tobacco only. Smokers included in this analysis were found to have a moderate to low heaviness of smoking index score. The lowest average score was among those using products mentholated in a filter capsule only (1.3, SE = .10), and the highest among those using non-mentholated products (2.4, SE = .03). About 12% of smokers quit between W1 and W2. Cessation, nicotine dependence and quit attempts at W2 were not associated with delivery method of menthol at W1.

Conclusions:

Method of menthol delivery was not found to impact cessation, nicotine dependent and quit attempts.

Menthol is the only characterizing flavor allowed to be added to cigarettes sold in the US, in accordance with the Family Prevention and Tobacco Control Act of 2009 (aka Tobacco Control Act).¹ Menthol has been shown to reduce the harshness of cigarette smoke and irritation caused by nicotine, which contributes to initiation and continuation of cigarette use.^2–8 In addition, some evidence suggests that menthol slows the metabolism of nicotine.^2,9–10 This would ultimately enhance nicotine exposure resulting in greater rewarding of the behavior, and potentially increasing the level of nicotine dependence and delaying cessation.^2,11–12 However, past research is conflicting.^13–15

Menthol flavoring can be added to cigarettes in various ways, including spraying the cut tobacco during blending, adding it to the pack foil, injecting into the tobacco stream in the cigarette maker, use of a crushable capsule in the filter, or any combination of these.¹⁶ The crushable filter capsule allows for a greater concentration of menthol to be transferred to the smoke because the menthol is not burned with the tobacco.¹⁷ In addition, because the capsule may limit migration of the menthol flavor to other cigarette components, the flavor may not dissipate with time or after the cigarette pack is opened.¹⁷ Therefore, the capsule may increase menthol intake, increasing nicotine exposure and reducing quit attempts and successful cessation. In the US, there are two brands that supply varieties of mentholated cigarettes with crushable menthol capsules in the cigarette filters, Camel (Crush and Menthol) and Marlboro (NXT), wherein Camel Menthol cigarettes are mentholated in the tobacco as well as with a crushable filter capsule.

To our knowledge, no studies have examined the longitudinal associations of various menthol delivery methods with cessation, nicotine dependence, and quit attempts. Using data from the Population Assessment of Tobacco and Health (PATH) Study, Waves 1 and 2 (W1 & W2), this study aimed to identify differences in successful cessation, nicotine dependence and past quit attempts according to type of menthol delivery method among US smokers.

METHODS

Study Design and Participants

The PATH study is an ongoing, nationally representative, longitudinal cohort study of tobacco use behaviors, attitudes and beliefs, and tobacco-related health outcomes among US youth (12–17 years) and adults (18 years and older).¹⁸ W1 adult data (N = 32,320) were collected between 12 September 2013 and 14 December 2014, and W2 data (N = 28,362) were collected between 23 October 2014 and 30 October 2015 (weighted response rate: 83.2%). The PATH study was conducted by Westat (Rockville, MD), approved by the Westat Institutional Review Board, and informed consent was obtained from participants. More detailed information on the PATH study sampling design, data collection, weighting, and data files is available elsewhere.¹⁹ This study reports longitudinal estimates from 8,292 current adult cigarette smokers (have smoked at least 100 cigarettes in their lifetime and smoke every day or somedays) in the US at W1 who participated in W1 and W2 of the PATH Study public-use files and reported a usual brand of cigarettes at W1.

Measures

Usual brand of cigarettes.

Usual brand of cigarettes was assessed in order to determine mentholation status and to identify mentholated products known to use a crushable filter capsule. At W1, current and former smokers (N = 11,632) were asked to select their usual brand from pictures provided. The usual brand of current smokers from W1 (N = 10,238) was categorized into one of four possible categories reflecting the brand’s type of menthol delivery: no menthol as a categorizing flavor (non-menthol), mentholated in the tobacco only, mentholated using a crushable capsule in the cigarette’s filter only, or mentholated in both the tobacco and a crushable filter capsule. There were 8,292 current smokers with usual brand data at W1 who continued on to W2.

Successful cessation, nicotine dependence, and past quit attempts.

Successful cessation was determined if a participant was a current “everyday” or “someday” smoker at W1 but not at W2.^20,21 The Heaviness of Smoking Index (HSI)²² was used as a proxy for nicotine dependence at W1 and W2. Smokers receive a score (ranging from 0 to 6) based on cigarettes per day and time to first cigarette of the day.²² Quit attempts in the past 12 months was assessed at W2 among current smokers using the following question, ‘In the past 12 months, have you stopped smoking for one day or longer because you were trying to quit?’

Statistical Analysis

Weighted cross-sectional prevalence estimates of current smokers’ demographic and behavioral characteristics ascertained at W1 were examined according to their usual brand menthol delivery method. Weighted within-person rates of successful cessation, change in nicotine dependence and quit attempts in the past 12 months among menthol delivery method between W1 and W2 were assessed. All models were adjusted for sex, age, race/ethnicity, education and poverty status. Smoking frequency and cigarettes per day were included in models for successful cessation and quit attempts. All analyses were performed using Stata version 14 (StataCorp, College Station, TX). Analyses were conducted using study weights developed by Westat to account for the PATH Study’s complex survey design and to represent the US adult population.¹⁹ Variances were estimated using balanced repeated replication with a Fay’s adjustment of 0.3 to increase estimate stability. A p < .05 was considered statistically significant.

RESULTS

A total of 8,292 participants reported a regular brand of cigarettes, which when weighted represented approximately 30.6 million US adults. Of the participants that reported a regular brand of cigarettes, 4,844 (60.5%) smoked a non-mentholated brand of cigarettes, 2,946 (34.3%) smoked a brand that was mentholated in the tobacco, 271 (3.0%) smoked a brand that was mentholated in a filter capsule, and 231 (2.3%) smoked a brand that was mentholated in both the tobacco and a filter capsule.

About 12% of smokers quit between W1 and W2. Among current smokers at W1 and W2, statistically significant differences were seen in quit attempts in the past 12 months at W2 by preferred type of mentholation at W1 (p=0.0119). There were 4,733 smokers at W2 that, in the past 12 months, had stopped smoking for one day or longer because they were trying to quit smoking. At W2, 62.7% of smokers who preferred non-mentholated cigarettes, 66.1% of smokers who preferred a brand of cigarettes mentholated in the tobacco only, 69.5% of smokers who preferred a brand of cigarettes mentholated in a crushable filter capsule only, and 61.6% of participants who preferred a brand of cigarettes mentholated in both the tobacco and a crushable filter capsule had stopped smoking for one day or longer in the past 12 months because they were trying to quit smoking. Current smokers who reported a preferred brand at W1 and continued to smoke at W2, on average showed low to moderate nicotine dependence (mean HSI: 2.24, SE: 0.03). Significant differences across mentholation types were seen, with smokers of non-mentholated cigarettes having highest scores (2.4, SE=0.03) and smokers of cigarettes with menthol capsule only the lowest (1.3, SE=0.10). However, after adjustment, regression models and pairwise comparisons did not show an association of menthol delivery method at W1 with successful cessation, past quit attempts, or HSI at W2 (Table 1).

Table 1:

Association of Delivery Method of Menthol at W1 with Successful Cessation, Past Quit Attempts, and Heaviness of Smoking at W2 - Data from the PATH Study (2013–2015)

	Non-Menthol (N = 4,844)			Menthol in Tobacco only (N = 2,946)					Menthol in Capsule only (N = 271)					Menthol in both Tobacco and Capsule (N = 231)
Outcomes at W2	N	% (SE)		N	% (SE)	Crude OR (95%CI)	Adjusted OR (95%CI)a		N	% (SE)	Crude OR (95%CI)	Adjusted OR (95%CI)a		N	% (SE)	Crude OR (95%CI)	Adjusted OR (95%CI)a
Successfully quit	548	11.6 (0.57)		307	10.9 (0.80)	0.93 (0.76. 1.15)	1.09 (0.88, 1.37)		48	17.8 (2.55)	1.66 (1.17, 2.35)	1.21 (0.77, 1.90)		40	17.1 (2.8)	1.57 (1.05, 2.36)	1.48 (0.97, 2.25)
Current Smokers at W2
	Non-Menthol (N = 4,274)			Menthol in Tobacco only (N = 2,625)					Menthol in Capsule only (N = 221)					Menthol in both Tobacco and Capsule (N = 191)
Made past quit attempt	2710	62.7 (0.78)		1740	66.1 (0.99)	1.16 (1.04, 1.29)	1.00 (0.89, 1.13)		158	69.5 (3.03)	1.36 (1.01, 1.83)	1.14 (0.83, 1.57)		125	61.6 (3.95)	0.95 (0.68, 1.34)	0.74 (0.52, 1.06)
	Non-Menthol (N = 4,167)			Menthol in Tobacco only (N = 2,551)					Menthol in Capsule only (N = 209)					Menthol in both Tobacco and Capsule (N = 186)
	N	Mean (SE)		N	Mean (SE)	Crude β (95%CI)	Adjusted β (95%CI)b		N	Mean (SE)	Crude β (95%CI)	Adjusted β (95%CI)b		N	Mean (SE)	Crude β (95%CI)	Adjusted β (95%CI)b
HSI	4,353	2.27 (0.04)		2,639	2.06 (0.03)	−0.08 (−0.15, −0.02)	−0.05 (−0.12, 0.03)		220	1.35 (0.11)	−0.13 (−0.29, 0.03)	−0.04 (−0.20, 0.12)		197	1.76 (0.13)	−0.19 (−0.36, −0.02)	−0.13 (−0.30, 0.03)

Abbreviations: HSI-Heaviness of smoking index; OR-Odds Ratio; 95%CI-95% Confidence Interval

Bolded point estimates indicate statistical significance (p < .05).

^a:Adjusted for sex, age, race/ethnicity, education, and heaviness of smoking index.

^b:Adjusted for sex, age, race/ethnicity, and education.

DISCUSSION

Findings from the PATH Study, W1 and W2, a nationally representative, longitudinal cohort study in the US, indicate that about 61% of current adult smokers’ regular cigarette brand was not mentholated, and nearly 39% of current adult smokers’ regular cigarette brand was mentholated in 2013 and 2014. A total of 34% of current adult smokers used a brand mentholated only in the tobacco, 3% used a brand mentholated only with a crushable filter capsule, and 2% used a brand that was mentholated in both the tobacco and with a crushable filter capsule. The current study, however, did not identify differences in nicotine dependence, successful cessation, or past quit attempts according to the delivery method of menthol, after adjustment for demographic and smoking behavior characteristics, which aligns with previous studies.^13,14,20,21

The PATH study has strong external validity, internal validity, and retention rates,²¹ but there are still some limitations to note. Despite the large overall sample size, the statistical power was limited by the moderate number of users in the “menthol in capsule only” and “menthol in both tobacco and capsule” categories. Although we assessed self-reported cessation between waves, it was collected at a single time point so we cannot be sure of cessation duration. The data, including usual cigarette brand, are self-reported, and cessation was not bioverified. In the future, bioverfication of cessation over a longer period of time would be ideal. Finally, the current cigarette users in this study may have been concurrently using other tobacco products. Therefore, the effect of other tobacco product use on cessation, nicotine dependence, and quit attempts should be assessed in the future.

In conclusion, we observed that cigarettes mentholated with a crushable filter capsule--with or without menthol as a characterizing flavor in the tobacco were used by about 5% of smokers in the US. The consumers of filter capsule products are more likely to be young adults,^15–17,19 and they are drawn to them because of their taste and pack design.¹⁶ However, delivery method of menthol does not seem to affect nicotine dependence, successful cessation or past quit attempts.