ArticlePDF Available

Abstract and Figures

Background: A major characteristic of the electronic cigarette (EC) market is the availability of a large number of different flavours. This has been criticised by the public health authorities, some of whom believe that diverse flavours will attract young users and that ECs are a gateway to smoking. At the same time, several reports in the news media mention that the main purpose of flavour marketing is to attract youngsters. The importance of flavourings and their patterns of use by EC consumers have not been adequately evaluated, therefore, the purpose of this survey was to examine and understand the impact of flavourings in the EC experience of dedicated users. Methods: A questionnaire was prepared and uploaded in an online survey tool. EC users were asked to participate irrespective of their current smoking status. Participants were divided according to their smoking status at the time of participation in two subgroups: former smokers and current smokers. Results: In total, 4,618 participants were included in the analysis, with 4,515 reporting current smoking status. The vast majority (91.1%) were former smokers, while current smokers had reduced smoking consumption from 20 to 4 cigarettes per day. Both subgroups had a median smoking history of 22 years and had been using ECs for 12 months. On average they were using three different types of liquid flavours on a regular basis, with former smokers switching between flavours more frequently compared to current smokers; 69.2% of the former subgroup reported doing so on a daily basis or within the day. Fruit flavours were more popular at the time of participation, while tobacco flavours were more popular at initiation of EC use. On a scale from 1 (not at all important) to 5 (extremely important) participants answered that variability of flavours was "very important" (score = 4) in their effort to reduce or quit smoking. The majority reported that restricting variability will make ECs less enjoyable and more boring, while 48.5% mentioned that it would increase craving for cigarettes and 39.7% said that it would have been less likely for them to reduce or quit smoking. The number of flavours used was independently associated with smoking cessation. Conclusions: The results of this survey of dedicated users indicate that flavours are marketed in order to satisfy vapers' demand. They appear to contribute to both perceived pleasure and the effort to reduce cigarette consumption or quit smoking. Due to the fact that adoption of ECs by youngsters is currently minimal, it seems that implementing regulatory restrictions to flavours could cause harm to current vapers while no public health benefits would be observed in youngsters. Therefore, flavours variability should be maintained; any potential future risk for youngsters being attracted to ECs can be sufficiently minimized by strictly prohibiting EC sales in this population group.
Content may be subject to copyright.
Int. J. Environ. Res. Public Health 2013, 10, 7272-7282; doi:10.3390/ijerph10127272
International Journal of
Environmental Research and
Public Health
ISSN 1660-4601
www.mdpi.com/journal/ijerph
Article
Impact of Flavour Variability on Electronic Cigarette Use
Experience: An Internet Survey
Konstantinos E. Farsalinos 1,*, Giorgio Romagna 2, Dimitris Tsiapras 1, Stamatis Kyrzopoulos 1,
Alketa Spyrou 1 and Vassilis Voudris 1
1 Onassis Cardiac Surgery Center, Sygrou 356, Kallithea 17674, Greece;
E-Mails: dtsiapras@hotmail.com (D.T.); stkyrz@gmail.com (S.K.); aspirou@gmail.com (A.S.);
vvoudris@otenet.gr (V.V.)
2 ABICH S.r.l, Biological and Chemical Toxicology Research Laboratory, Via 42 Martiri, 213/B-28924
Verbania (VB), Italy; E-Mail: giorgio.romagna@gmail.com
* Author to whom correspondence should be addressed; E-Mail: kfarsalinos@gmail.com;
Tel.: +306-977-454-837; Fax: +302-109-493-373.
Received: 19 November 2013; in revised form: 11 December 2013 / Accepted: 12 December 2013 /
Published: 17 December 2013
Abstract: Background: A major characteristic of the electronic cigarette (EC) market is
the availability of a large number of different flavours. This has been criticised by the
public health authorities, some of whom believe that diverse flavours will attract young
users and that ECs are a gateway to smoking. At the same time, several reports in the news
media mention that the main purpose of flavour marketing is to attract youngsters. The
importance of flavourings and their patterns of use by EC consumers have not been
adequately evaluated, therefore, the purpose of this survey was to examine and understand
the impact of flavourings in the EC experience of dedicated users. Methods:
A questionnaire was prepared and uploaded in an online survey tool. EC users were asked
to participate irrespective of their current smoking status. Participants were divided
according to their smoking status at the time of participation in two subgroups: former
smokers and current smokers. Results: In total, 4,618 participants were included in the
analysis, with 4,515 reporting current smoking status. The vast majority (91.1%) were
former smokers, while current smokers had reduced smoking consumption from 20 to
4 cigarettes per day. Both subgroups had a median smoking history of 22 years and had
been using ECs for 12 months. On average they were using three different types of liquid
flavours on a regular basis, with former smokers switching between flavours more
OPEN ACCESS
Int. J. Environ. Res. Public Health 2013, 10 7273
frequently compared to current smokers; 69.2% of the former subgroup reported doing so
on a daily basis or within the day. Fruit flavours were more popular at the time of
participation, while tobacco flavours were more popular at initiation of EC use. On a scale
from 1 (not at all important) to 5 (extremely important) participants answered that
variability of flavours was “very important” (score = 4) in their effort to reduce or quit
smoking. The majority reported that restricting variability will make ECs less enjoyable
and more boring, while 48.5% mentioned that it would increase craving for cigarettes and
39.7% said that it would have been less likely for them to reduce or quit smoking. The
number of flavours used was independently associated with smoking cessation.
Conclusions: The results of this survey of dedicated users indicate that flavours are
marketed in order to satisfy vapers’ demand. They appear to contribute to both perceived
pleasure and the effort to reduce cigarette consumption or quit smoking. Due to the fact
that adoption of ECs by youngsters is currently minimal, it seems that implementing
regulatory restrictions to flavours could cause harm to current vapers while no public
health benefits would be observed in youngsters. Therefore, flavours variability should be
maintained; any potential future risk for youngsters being attracted to ECs can be
sufficiently minimized by strictly prohibiting EC sales in this population group.
Keywords: electronic cigarette; flavours; smoking; tobacco; nicotine; smoking cessation;
public health
1. Introduction
Cigarette smoking is considered the single most preventable cause of disease, affecting several
systems in the human body and causing premature death [1]. The World Health Organisation predicts
more than 1 billion deaths within the 21st century related to tobacco cigarettes [2]. Although there is
overwhelming evidence for the benefits of smoking cessation [3], it is a very difficult addiction to
break. Currently available nicotine replacement therapy have low long-term success rate, which may
be attributed solely to psychological support [4], while oral medications are more effective [5] but are
hindered by reports of adverse neuropsychiatric effects [6]. In this context, the tobacco harm reduction
strategy has been developed, with a goal of providing nicotine through alternative methods in order to
reduce the amount of harmful substances obtained by the user [7].
Electronic cigarettes (ECs) have been marketed in recent years as alternative to smoking products.
They consist mainly of a battery and an atomiser where liquid is stored and gets evaporated by energy
supplied to an electrical resistance. The liquid contains mainly propylene glycol and glycerol, with the
option to include nicotine. A major characteristic of the EC liquid market is the availability of a variety
of flavourings. Besides tobacco-like flavours, the consumer can choose flavours consisting of fruits,
sweets, drinks and beverages and many more. The availability of so many flavours has been criticized
by authorities such as the Food and Drug Administration (FDA), stating that there is a potential to
attract youngsters [8]. Such a concern was probably raised by the experience with tobacco products,
with studies showing that flavoured cigarettes were more appealing to young users [9]. A recent survey
Int. J. Environ. Res. Public Health 2013, 10 7274
of electronic cigarette users found that almost half of participants were using non-tobacco flavours [10].
However, no survey was specifically designed to detect the impact of flavourings on EC experience by
users. Therefore, the purpose of this survey was to evaluate the patterns of flavourings use and
determine their popularity in a sample of dedicated adult EC users.
2. Methods
A questionnaire was prepared by the research team in two languages (English and Greek) and was
uploaded in an online survey tool (www.surveymonkey.com). A brief presentation of the survey was
uploaded in the website of a non-profit EC advocates group (www.ecigarette-research.com) together
with informed consents in English and Greek. If the participant agreed with the informed consent, he
was redirected to the questionnaire in the respective language by pressing the “I agree” button. The survey
was available online for 15 days. The protocol was approved by the ethics committee of our institution.
EC users of any age, irrespective of current or previous smoking status, were asked to participate to
the survey. The survey was communicated in internet social media and several EC users’ forums and
advocate groups worldwide. The IP address of the participants was recorded in order to remove double
entries. There was an option for participants to report their email address for participation in future
projects; unwillingness to report the email address was not a criterion for exclusion from the survey.
Information about age, gender, country of residence and education level was requested. Past and
present smoking status was asked and, based on the latter, participants were divided into two groups
for the analysis: former smokers who had completely quit smoking and smokers who were still
smoking after initiation of EC use. The questionnaire included questions about the type of flavours
used regularly by the participants, whether the variety of flavourings was important in reducing or
completely substituting smoking and defining the reasons for using multiple flavours. To assess
difficulty in finding flavours of their preference at EC use initiation, the following question was asked:
“Was it difficult to find the flavourings of your preference at initiation of EC use?”. The answers were
scored as: 1, “not at all difficult”; 2, “slightly difficult”; 3, “difficult”; 4, “very difficult”; and
5, “extremely difficult”. To examine the importance of flavours variability in reducing or quitting
smoking, the following question was asked: “Was the variability of flavourings important in your
effort to reduce or completely substitute smoking?”. The answer was scored as: 1, “not at all important”;
2, “slightly important”; 3, “important”; 4, “very important”; and 5, “extremely important”.
3. Statistical Analysis
Participants were categorised into current smokers and former-smokers according to their reported
status at the time of participation to the survey. Results are reported for the whole sample and for each
of the subgroups. The sample size varied by variable because of missing data. In some questions,
responders were allowed to choose more than one option; in these cases, each answer is presented
separately and the sum of responses may exceed 100%. Kolmogorov-Smirnoff tests were performed to
assess normality of distribution of variables. Continuous variables are reported as median (interquartile
range [IQR]). Categorical variables are reported as number (percentage). Mann Whitney U test was
used to compare continuous variables between current and former smokers, while cross tabulations
with χ2 test were used for categorical variables. Finally, a stepwise binary logistic regression analysis
Int. J. Environ. Res. Public Health 2013, 10 7275
was performed, with smoking status (former vs. current smoker) as the independent variable and age,
gender, education level, smoking duration, number of flavourings used regularly, and EC consumption
(ml liquid or number of prefilled cartomisers) as covariates. A two-tailed P value of <0.05 was
considered statistically significant, and all analyses were performed with commercially available
statistical software (SPSS v. 18, Chicago, IL, USA).
4. Results
4.1. Baseline Characteristics
After excluding double entries, 4,618 participants were included to the analysis, with 4,515
reporting current smoking status (current vs. former smokers). The baseline characteristics of the study
group and subgroups are displayed in Table 1. More than 90% were former smokers. The mean age
was 40 years, with male predominance. No difference between former and current smokers was
observed in age, while more males were former smokers. The vast majority were from America and
Europe, with a small proportion residing in Asia and Australia. More than half of participants were
educated to the level of university/college. Smoking duration was similar between subgroups.
Interestingly, former smokers reported higher daily cigarette consumption before initiation of EC use,
although the difference was not statistically significant. Current smokers reported a substantial
reduction in cigarette consumption, from 20 to 4 cigarettes per day. The median duration of EC use
was 12 months, with higher consumption (ml liquid or number of cartridges) reported by former
smokers. Higher nicotine concentration liquids were used by current smokers (P = 0.005). In total, 140
participants (3.0%) reported using non-nicotine liquids, 2.8% of former and 1% of current smokers
(χ2 = 4.5, P = 0.033); 21 users of non-nicotine liquids did not mention their current smoking status.
Finally, more current smokers were using first (cigarette-like) and second generation (eGo-type)
devices while more former smokers were using third generation devices (also called “Mods”, variable
voltage or wattage devices).
4.2. Perceptions in Relation to Flavours
Responses to questions related to flavours are displayed in Table 2. At the time of participation,
most commonly used flavours were fruits, followed by sweets and tobacco. Significant differences
were observed between subgroups. Characteristically, more current smokers were using tobacco
flavours compared to former smokers, while more of the latter were using fruit and sweet flavours. On
a regular basis, participants reported using 3 (IQR: 2–4) different types of flavours. At initiation of EC
use, most popular flavours were tobacco followed by fruit and sweet flavours. The median score for
difficulty to find the flavours of their preference at EC initiation was 2 (IQR: 1–3), with no difference
between subgroups. Most participants (68.3%) were switching between flavours on a daily basis or
within the day, with former smokers switching more frequently. More than half of the study sample
mentioned that they like the variety of flavours and that the taste gets blunt from long-term use of the
same flavour. The average score for importance of flavours variability in reducing or quitting smoking
was 4 (“very important”). Finally, the majority of participants stated that restricting variability of
flavours would make the EC experience less enjoyable while almost half of them answered that it
Int. J. Environ. Res. Public Health 2013, 10 7276
would increase craving for tobacco cigarettes and would make reducing or completely substituting
smoking less likely.
Table 1. Baseline characteristics of the study population and subgroups.
Characteristic Total Former Smokers Current Smokers Statistic P
Participants, n (%) 4,618 4,117 (91.2) 398 (8.8)
English translation 4,386 (95.0) 3,915 (95.1) 369 (92.7)
Greek translation 232 (5.0) 202 (4.9) 29 (7.3)
Region of residence, n (%)
America 2,220 (48.5) 2,007 (48.7) 157 (39.4)
Asia 76 (1.7) 58 (1.4) 16 (4.0)
Australia 80 (1.7) 75 (1.8) 4 (1.0)
Europe 2,197 (48.0) 1,939 (47.1) 217 (54.5)
Education, n (%)
High school or less 1,037 (22.7) 917 (22.3) 98 (24.6)
Technical Education 1,099 (24.1) 993 (24.1) 86 (21.6)
University/College 2,425 (53.2) 2,170 (52.7) 206 (51.8)
Age (years) 40 (32–49) 40 (32–49) 40 (32–49) U = 754,278 0.624
Gender (male) 3,229 (71.8) 2,922 (72.7) 246 (62.5) χ2 = 18.0 <0.001
Smoking duration (years) 22 (15–30) 22 (15–30) 22 (14–30) U = 816,534 0.924
Cigarette consumption before EC use (/d) 24 (20–30) 25 (20–30) 20 (19–30) U = 768,398 0.189
Cigarettes consumption after EC use (/d) 4 (2–6)
EC use duration (months) 12 (6–23) 12 (6–23) 12 (5–23) U = 790,219 0.373
EC consumption (ml or cartridges/d) 4 (3–5) 4 (3–5) 3 (2–5) U = 677,862 <0.001
Nicotine levels in EC (mg/ml) 12 (6–18) 12 (6–18) 12 (8–18) U = 722,563 0.005
EC devices used, n (%)
Cigarette-like 84 (1.8) 61 (1.5) 20 (5.0) χ2 = 25.9 <0.001
eGo-type 1,123 (24.7) 966 (23.5) 133 (33.4) χ2 = 19.5 <0.001
“Mods” a 3,348 (73.5) 3,047 (74.0) 237 (59.5) χ2 = 38.3 <0.001
Notes: Values presented as median (interquartile range) or number (percentage). Abbreviations: EC, electronic
cigarette. a New generation devices, usually hand-made or with the ability to manually set the voltage or
wattage delivery.
Table 2. Patterns of flavourings use in the study population and subgroups.
Characteristic Total Former Smokers Current Smokers Statistic P
Flavours used now, n (%) a
Tobacco 1,984 (43.9) 1,773 (43.1) 211 (53.0) χ2 = 14.6 <0.001
Mint/menthol 1,468 (31.8) 1,339 (32.5) 129 (32.4) χ2 = 0.0 0.964
Sweet 2,836 (61.4) 2,629 (63.9) 207 (52.0) χ2 = 21.8 <0.001
Nuts 691 (15.0) 643 (15.6) 48 (12.1) χ2 = 3.5 0.060
Fruits 3,203 (69.4) 2,953 (71.7) 250 (62.8) χ2 = 14.0 <0.001
Drinks/beverages 1,699 (36.8) 1,562 (37.9) 137 (34.4) χ2 = 1.9 0.167
Other 1,028 (22.3) 946 (23.0) 82 (20.6) χ2 = 1.2 0.281
Int. J. Environ. Res. Public Health 2013, 10 7277
Table 2. Cont.
Flavours used at EC initiation, n (%) a
Tobacco 3,118 (69.1) 2,846 (69.1) 272 (68.3) χ2 = 0.1 0.746
Mint/menthol 1,086 (24.1) 1,004 (24.4) 82 (20.6) χ2 = 2.8 0.092
Sweet 1,347 (29.8) 1,251 (30.4) 96 (24.1) χ2 = 6.8 0.009
Nuts 203 (4.5) 186 (4.5) 17 (4.3) χ2 = 0.1 0.821
Fruits 1,743 (38.6) 1,606 (39.0) 137 (34.4) χ2 = 3.2 0.073
Drinks/beverages 808 (17.9) 748 (16.8) 60 (15.1) χ2 = 2.4 0.124
Other 302 (6.7) 282 (6.8) 20 (5.0) χ2 = 1.9 0.164
Switching between flavours, n (%)
Daily/within the day 3,083 (68.3) 2,851 (69.2) 232 (58.3) χ2 = 20.1 <0.001
Weekly 718 (15.9) 636 (15.4) 82 (20.6) χ2 = 7.2 0.007
Less than weekly 465 (10.3) 412 (10.0) 53 (13.3) χ2 = 4.3 0.038
At EC initiation, was it difficult to
find the flavours of your preference? b 2 (1–3) 2 (1–3) 2 (1–3) U = 760,068 0.054
Why do you feel the need to choose different flavours? n (%) a
Like variety of choices 3,300 (73.1) 3,041 (73.9) 259 (65.1) χ2 = 14.3 <0.001
They get “blunt” from long-term use 2,325 (51.5) 2,131 (51.8) 194 (48.7) χ2 = 1.3 0.250
Other reasons 342 (7.6) 318 (7.7) 24 (6) χ2 = 1.5 0.223
Was flavours variability important
in reducing/quitting smoking? b 4 (3–5) 4 (3–5) 4 (3–5) U = 731,547 0.455
How would your experience with EC change if flavours variability was limited? n (%) a
Less enjoyable 3,111 (68.9) 2,886 (70.1) 225 (56.5) χ2 = 31.2 <0.001
More boring 2,063 (45.7) 1,901 (46.2) 236 (40.7) χ2 = 4.4 0.036
Increase craving for cigarettes 2,188 (48.5) 1,982 (48.1) 206 (51.8) χ2 = 1.9 0.168
Less likely to reduce or quit smoking 1,793 (39.7) 1,617 (39.3) 176 (44.2) χ2 = 3.7 0.054
No difference 285 (6.3) 253 (6.1) 32 (8.0) χ2 = 2.2 0.138
Notes: Values presented as median (interquartile range) or number (percentage). Abbreviations: EC, electronic
cigarette. a Participants were allowed to choose more than one answers. b Score reported (see text for details).
Binary logistic regression analysis showed that male gender (B = 0.373, P = 0.001),
EC consumption (B = 0.046, P = 0.044) and number of flavours regularly used (B = 0.089, P = 0.038)
were associated with complete smoking abstinence in this population of dedicated long-term vapers,
while age, education level and smoking duration were not associated with smoking abstinence.
5. Discussion
This is the first survey that specifically focused on the issue of flavours and their impact in EC use.
A substantial number of dedicated EC consumers participated; they reported that flavours play an
important role in their EC use experience and in reducing cigarette consumption and craving, while the
number of flavours regularly used was independently associated with complete smoking abstinence in
this population.
The availability of a variety of flavours has been a controversial issue since the initial appearance of
ECs to the market. Most companies offer a variety of flavours, from those resembling tobacco to a large
Int. J. Environ. Res. Public Health 2013, 10 7278
number commonly used in the food industry. Public health authorities have raised concerns about this
issue, and several statements have been released suggesting flavours could attract youngsters [8,11,12].
Such concerns are probably rooted back to the marketing of the tobacco industry for flavoured tobacco
cigarettes. Internal industry documents and published surveys indicated that flavoured tobacco
products are more appealing to youngsters and may be a gateway to maintaining smoking as a long
term habit, while use by adults was quite low [13–16]. This is the main reason why the FDA decided
to implement a ban on characteristic flavours in tobacco cigarettes [17]. It was expected that such
concerns would be raised for ECs, although current vapers are overwhelmingly adults. Anecdotal
evidence from EC consumers’ internet forums and results from surveys [10] have shown that different
flavours are very popular among dedicated users. The results of this survey confirm previous
observations by finding that dedicated users switch between flavours frequently and the variability of
flavours plays an important role both in reducing cigarette craving and in perceived pleasure.
Moreover, the number of flavours used was associated with smoking cessation. Therefore, flavours
variability is needed to support the demand by current vapers, who are in their vast majority adults.
This survey also indicated that there is a switch in flavours preference of EC consumers; tobacco is the
preferred flavour when initiating EC use, probably because smokers are used to this flavour and feel
the need to use something that resembles their experience from smoking. However, different choices
are made as time of use progresses. This may be a way to distract them from the tobacco flavour in
order to reduce smoking craving; alternatively, it could indicate that they just don’t need the tobacco
flavour any more, but feel the desire to experiment with new flavours. In some cases, tobacco flavour
may even become unpleasant, especially in those who have completely quit smoking. The
improvement in olfactory and gustatory senses in these people can lead to both more pleasure
perceived from different flavours and an aversion to tobacco flavour (in a similar way that it is unpleasant
for a non-smoker); the latter has been reported in EC consumers’ forums (http://www.e-cigarette-
forum.com/forum/polls/209041-do-you-vape-tobacco-flavors.html). Such a phenomenon may contribute to
lower relapse to smoking and may prevent the EC from being a gateway to smoking; however, this
should be specifically studied before making any conclusions. Finally, the issue of taste buds
“tolerance”, which is anecdotally mentioned by vapers, was reported by almost half of the sample as a
reason to switch between flavours, although it is most probably a type of olfactory rather than
gustatory tolerance.
Besides information on the use of flavourings, this survey provides information on other issues
related to EC use. A small minority of participants were using first generation cigarette-like devices.
This has been observed in other surveys [10]. There was a higher prevalence of third-generation
devices used in the subgroup of former smokers compared to current smokers. Such devices have the
ability to provide higher energy to the atomiser, thus producing more vapour and delivering more
pleasure to the user [18,19]. Until now, two randomised studies evaluating the efficacy of EC use in
smoking cessation have used first-generation cigarette-like devices [20,21]. It is possible that newer
generation devices may be more effective in substituting smoking, and this should be evaluated in
future studies. Additionally, former smokers were using lower nicotine-concentration liquids compared
to current smokers. It has been observed from previous studies that EC users who have completely
substituted smoking try to gradually reduce their nicotine use [18]. Despite that, only 2.8% of former
smokers were using 0-nicotine liquids at the time of survey participation, indicating that nicotine is
Int. J. Environ. Res. Public Health 2013, 10 7279
important in smoking abstinence and that EC consumers remain long-term nicotine users. However,
the possibility that several vapers may quit EC use shortly after switching to non-nicotine liquids
cannot be excluded; such users would not participate to this survey, therefore overestimating the
significance of nicotine on EC use. Finally, we observed a male predominance in participation to this
survey, which is in line with previous studies [10,18]. In this survey, males were more likely to have
completely quit smoking. Further studies are needed to explore this phenomenon and define whether
females are less successful in smoking cessation with EC use, are less motivated long-term users or
use ECs in the short term as smoking substitutes.
There are some limitations applicable to this study. The survey was announced and promoted in
popular EC websites. Therefore, it is expected that dedicated users with positive experience with ECs
would mainly participate, and the high proportion of former smokers confirms this. However, it is
important to evaluate the patterns of use in smokers who have successfully quit smoking, since this can
provide health officials with information on how to educate smokers into using ECs, especially during
the initial period of use. Although a significant proportion stated that flavours play a major role in
reducing or quitting smoking, this study was not designed to evaluate whether variability of flavours
may promote smoking cessation in the general population; moreover our sample is not representative
of the general population of smokers, who are generally less educated compared to the population
evaluated here [22]. This should be evaluated in a randomised study. Finally, although the fact that
flavours are important for existing EC users provides sufficient explanation for their current marketing,
it does not exclude the possibility that they may also attract youngsters. However, currently available
evidence indicates that regular use of ECs by non-smoking adults or youngsters is very limited [23–25];
thus, any restriction of flavours for the reason of protecting youngsters is currently not substantiated by
evidence and no public health benefit would be derived. On the contrary, such a measure could have a
negative impact and cause harm in current vapers, who are reporting that they enjoy flavours and that
restrictions would make smoking reduction or cessation more difficult and would increase cigarette
craving. Therefore, it would be more realistic and valuable to promote restrictions to the use of ECs by
youngsters and to properly inform the public that ECs should be used only by smokers as a method to
reduce cigarette consumption or completely substitute smoking.
6. Conclusions
The results of this survey indicate that EC liquid flavourings play a major role in the overall
experience of dedicated users and support the hypothesis that they are important contributors in
reducing or eliminating smoking consumption. This should be considered by the health authorities;
based on the current minimal adoption of ECs by youngsters, it is reasonable to support that any
proposed regulation should ensure that flavourings are available to EC consumers while at the same
time restrictions to the use by youngsters (especially non-smokers) should be imposed in order to
avoid future penetration of EC use to this population.
Acknowledgements
We would like to thank E-Cigarette Research Advocates Group for promoting the survey in their
website (www.ecigarette-research.com). This is a non-profit group of electronic cigarette users with no
Int. J. Environ. Res. Public Health 2013, 10 7280
relation to the electronic cigarette or other industry. The website does not promote or present any
electronic cigarette product and do not accept any advertisements. The sole purpose of the group is to
inform about research conducted on electronic cigarettes. Konstantinos E. Farsalinos has been allowed
to present studies and post comments concerning electronic cigarette research on this website, without
providing or receiving any form of payment. We would also like to thank all other websites and
internet forums for promoting the survey and encouraging electronic cigarette users to participate.
None of the websites promoting the survey had any access to the data collected from participants. No
funding was received for this study.
Conflicts of Interest
The authors declare no conflict of interest.
References
1. Doll, R.; Peto, R.; Boreham, J.; Sutherland, I. Mortality in relation to smoking: 50 years’
observations on male British doctors. BMJ 2004, 328, 1519–1528.
2. World Health Organisation. Tobacco fact sheet No339. Updated, July 2013. Available online:
http://www.who.int/mediacentre/factsheets/fs339/en/ (accessed on 14 November 2013).
3. Taylor, D.H.; Hasselblad, V; Henley, S.J.; Thun, M.J.; Sloan, F.A. Benefits of smoking cessation
for longevity. Am. J. Public Health 2002, 92, 990–996.
4. Moore, D.; Aveyard, P.; Connock, M.; Wang, D.; Fry-Smith, A.; Barton, P. Effectiveness and
safety of nicotine replacement therapy assisted reduction to stop smoking: Systematic review and
meta-analysis. BMJ 2009, 338, b1024, doi:10.1136/bmj.b1024.
5. Rigotti, N.A.; Pipe, A.L.; Benowitz, N.L.; Arteaga, C.; Garza, D.; Tonstad, S. Efficacy and safety
of varenicline for smoking cessation in patients with cardiovascular disease: A randomized trial.
Circ. 2010, 121, 221–229.
6. Hays, J.T.; Ebbert, J.O. Adverse effects and tolerability of medications for the treatment of
tobacco use and dependence. Drugs 2010, 70, 2357–2372
7. Rodu, B.; Godshall, W.T. Tobacco harm reduction: An alternative cessation strategy for inveterate
smokers. Harm Reduct. J. 2006, 3, 37, doi:10.1186/1477-7517-3-37.
8. Food and Drug Administration. FDA and Public Health Experts Warn About Electronic Cigarettes;
2009 . Available o n l i n e : http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/
ucm173222.htm (accessed on 14 November 2013).
9. Lewis, M.J.; Wackowski, O. Dealing with an innovative industry: A look at flavored cigarettes
promoted by mainstream brands. Am. J. Public Health 2006, 96, 244–251.
10. Dawkins, L.; Turner, J.; Roberts, A.; Soar, K. “Vaping” profiles and preferences: An online survey
of electronic cigarette users. Addiction 2013, 108, 1115–1125.
Int. J. Environ. Res. Public Health 2013, 10 7281
11. Mayers, M.L. FDA Acts to Protect Public Health from Electronic Cigarettes. Campaign for
Tobacco-Free Kids Statement; 2009 . Available o n l i n e : http://www.tobaccofreekids.org/
press_releases/post/id_1166 (accessed on 14 November 2013).
12. National Association of Attorneys General. FDA Regulation on E-Cigarettes; 2013. Available online:
http://www.naag.org/assets/files/pdf/E%20Cigarette%20Final%20Letter%20(5)(1).pdf ( a ccessed o n
14 November 2013).
13. Connolly, G.N. Sweet and spicy flavours: New brands for minorities and youth. Tob. Control.
2004, 13, 211–212.
14. Carpenter, C.M.; Wayne, G.F.; Pauly, J.L.; Koh, H.K.; Connolly, G.N. New cigarette brands with
flavors that appeal to youth: Tobacco marketing strategies. Health Aff. 2005, 24, 1601–1610.
15. Klein, S.M.; Giovino, G.A.; Barker, D.C.; Tworek, C.; Cummings, K.M.; O’Connor, R.J. Use of
flavored cigarettes among older adolescent and adult smokers: United States, 2004–2005.
Nicotine Tob. Res. 2008, 10, 1209–1214.
16. Chung, P.J.; Garfield, C.F.; Rathouz, P.J.; Lauderdale, D.S.; Best, D.; Lantos, J. Youth targeting by
tobacco manufacturers since the Master Settlement Agreement. Health Aff. 2002, 21, 254–263.
17. Food and Drug Administration. Overview of the family smoking prevention and tobacco control act.
2009. Available onl ine: http://www.fda.gov/downloads/TobaccoProducts/GuidanceCompliance
RegulatoryInformation/UCM336940.pdf (accessed on 14 November 2013).
18. Farsalinos, K.E.; Romagna, G.; Tsiapras, D.; Kyrzopoulos, S.; Voudris, V. Evaluating nicotine
levels selection and patterns of electronic cigarette use in a group of “vapers” who had achieved
complete substitution of smoking. Subst. Abuse 2013, 7, 139–146.
19. Farsalinos, K.E.; Romagna, G.; Allifranchini, E.; Ripamonti, E.; Bocchietto, E.; Todeschi, S.;
Tsiapras, D.; Kyrzopoulos, S.; Voudris, V. Comparison of the cytotoxic potential of cigarette
smoke and electronic cigarette vapour extract on cultured myocardial cells. Int. J. Environ. Res.
Public Health 2013, 10, 5146–5162.
20. Caponnetto, P.; Campagna, D.; Cibella, F.; Morjaria, J.B.; Caruso, M.; Russo, C.; Polosa, R.
EffiCiency and Safety of an eLectronic cigAreTte (ECLAT) as tobacco cigarettes substitute:
A prospective 12-month randomized control design study. PLoS One 2013, 8, e66317, doi:10.137
1/journal.pone.0066317.
21. Bullen, C.; Howe, C.; Laugesen, M.; McRobbie, H.; Parag, V.; Williman, J.; Walker, N. Electronic
cigarettes for smoking cessation: A randomised controlled trial. Lancet 2013, 382, 1629–1637.
22. Centers for Disease Control and Prevention (CDC). Vital signs: Current cigarette smoking among
adults aged 18 years with mental illness—United States, 2009–2011. Morb. Mortal. Wkly. Rep.
2013, 62, 81–87.
23. Dockrell, M.; Morrison, R.; Bauld, L.; McNeill, A. E-cigarettes: Prevalence and attitudes in Great
Britain. Nicotine Tob. Res. 2013, 15, 1737–1744.
24. Camenga, D.R.; Delmerico, J.; Kong, G.; Cavallo, D.; Hyland, A.; Cummings, K.M.;
Krishnan-Sarin, S. Trends in use of electronic nicotine delivery systems by adolescents. Addict.
Behav. 2013, doi:10.1016/j.addbeh.2013.09.014, published online.
Int. J. Environ. Res. Public Health 2013, 10 7282
25. Lee, S.; Grana, R.A.; Glantz, S.A. Electronic cigarette use among Korean adolescents: A
Cross-Sectional Study of Market Penetration, Dual Use, and Relationship to Quit Attempts and
Former Smoking. J. Adolesc. Health 2013, doi: 10.1016/j.jadohealth.2013.11.003.
© 2013 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article
distributed under the terms and conditions of the Creative Commons Attribution license
(http://creativecommons.org/licenses/by/3.0/).
... In general, the most preferred/used flavors were fruit, mint/ menthol, and candy/dessert flavors. 21,27,62,64,[68][69][70][71][72][73][74][75] For cigarette smokers who recently bought a JUUL e-cigarette online, mint and mango were the most commonly used flavors. 76 Mint and fruit flavors were also the most preferred JUUL flavors for college student and adult JUUL ever-users. ...
... 62 Availability of a variety of flavors and the ability to switch between flavors was a valued aspect of e-cigarettes, and was often cited as a main reason for use-behind health and smoking cessation. 26,29,65,72 Flavor was also associated with increased intention to use, ever trying, and current use of e-cigarettes in college students. 82 However, another study of adult e-cigarette users found that neither preference for specific flavors nor total number of preferred flavors were significantly associated with e-cigarette use. ...
... 88 The number of flavors used may also be important, as one study found that the number of flavors used was associated with increased cigarette smoking cessation for dual users. 72 ln sum, the epidemiological studies suggest that nontobacco flavors are highly valued and increase the abuse potential and appeal of e-cigarettes. ...
Article
Introduction: Many adult cigarette smokers use electronic cigarettes (e-cigarettes) to cut down on or quit smoking cigarettes. E-cigarettes with higher abuse potential and appeal might facilitate complete switching. E-liquid nicotine concentration and flavor are two of the characteristics that may affect the abuse potential and appeal of e-cigarettes. The objective of this systematic review was to compile results from survey, animal, human laboratory, and clinical studies to understand the possible effects of nicotine concentration and flavor on abuse potential and appeal of e-cigarettes in adult current and former cigarette and e-cigarette users. Methods: A comprehensive literature search was conducted in Ovid Medline and PsycINFO followed by citation tracking in Web of Science Core Collection. Peer-reviewed studies published in English between 2007 and August 2020 were selected that analyzed differences between e-liquid nicotine concentration and/or flavors, had outcome measures related to abuse potential and/or appeal, and included adult humans (18+) or animals. 1624 studies were identified and screened. A qualitative synthesis of results was performed. Results: Results from 104 studies included in this review suggest that higher nicotine concentration and access to a variety of flavors are likely to be associated with higher abuse potential and appeal of e-cigarettes for adult current and former cigarette and e-cigarette users. Conclusions: Higher nicotine concentrations and the availability of a variety of flavors in e-cigarettes might facilitate complete substitution for cigarettes. Future e-cigarette regulations should take into account their impact on smokers, for whom e-cigarettes may be a cessation tool or reduced-harm alternative. Implications: E-cigarettes may provide a reduced-harm alternative to cigarettes for smokers unwilling/unable to quit or serve as a path for quitting all nicotine products. Higher nicotine concentrations and flavor variety are associated with higher abuse potential and appeal of e-cigarettes. Higher abuse potential and appeal products may help facilitate complete switching from cigarettes to e-cigarettes. Regulation of nicotine concentration and flavors aimed at decreasing naïve uptake may inadvertently decrease uptake and complete switching among smokers, reducing the harm reduction potential of e-cigarettes. Evidence-based effects of regulating nicotine concentration and flavors must be considered for the population as a whole, including smokers.
... 16 17 In an international survey, adult former smokers report that flavour variability was 'very important' when attempting to quit smoking and that restricting this would reduce enjoyment and increase cigarette craving. 18 A report from Great Britain indicated that if flavours were no longer available, 25% of adult e-cigarette users would still try to get them and 10% would make their own, 2 which indicate possible use of black markets and unregulated products. However, 18% said they would use unflavoured e-liquids/ cartridges. ...
... There was no clear evidence of an effect of e-liquid flavouring on average cigarette craving (mean difference 0. 18 The results did not differ after adjustment for baseline characteristics (table 2; see online supplemental table S4 for raw data). The results remained unchanged when excluding participants who experienced a smoking lapse (n=13, 15%) and those who failed the audio (n=1, 1%) and image (n=38, 45%; maximum 4/20 incorrect) attention checks (online supplemental table S5). ...
Article
Full-text available
Background E-liquid flavour restrictions may discourage electronic cigarette (e-cigarette) uptake among youth. However, possible unintended consequences may include reduced appeal and effectiveness of e-cigarettes for smoking cessation. Non-tobacco flavours appear to be important for smoking cessation, but how and why are currently unclear. Methods We conducted an experimental study in a UK sample of adult daily smokers using an independent groups design (N=84). Participants were randomised to use an e-cigarette with nicotine-containing fruit/sweet-flavoured e-liquid (blackcurrant, strawberry, vanilla, caramel) or unflavoured e-liquid for 1 week. The primary outcomes were average, peak and cue-elicited cigarette craving (the latter was assessed using a cue exposure task). The secondary outcomes were smoking lapse occurrence, enjoyment of the e-cigarette, ease of transitioning from smoking to using an e-cigarette, intentions to continue using an e-cigarette, intentions and motivation to quit smoking, return to smoking, and continuation of e-cigarette use. Results E-liquid flavouring did not appear to have an effect on average cigarette craving ( b 0.18, 95% CI −0.44 to 0.79, p=0.57), peak cigarette craving ( b −0.12, 95% CI −0.59 to 0.35, p=0.62) or cue-elicited cigarette craving ( b −0.21, 95% CI −3.86 to 3.43, p=0.91). We did not find evidence of a difference in secondary outcomes. Conclusions We did not find evidence to suggest that nicotine-containing fruit/sweet-flavoured and unflavoured e-liquids have different effects on cigarette cravings after 1 week of use. Further research is needed to establish if differences emerge over longer periods of exposure and extend to smoking cessation outcomes.
... The flavoring compounds used in EC e-liquids are generally regarded as safe (GRAS) for ingestion and employed extensively in the food industry. However, there are concerns regarding EC flavoring toxicity following inhalation using EC as evidence for safety following has not been extensively investigated (Farsalinos et al. 2013;Khlystov and Samburova 2016;Leigh et al. 2016;Sundar et al. 2016). In 2014, there were an estimated 8000 flavored e-liquids on the market, which has likely increased significantly (Zhu et al. 2014). ...
Article
Full-text available
Electronic cigarettes (ECs) are purported to be tobacco harm-reduction products whose degree of harm has been highly debated. EC use is considered less hazardous than smoking but is not expected to be harmless. Following the banning of e-liquid flavors in countries such as the US, Finland, Ukraine, and Hungary, there are growing concerns regarding the safety profile of e-liquid flavors used in ECs. While these are employed extensively in the food industry and are generally regarded as safe (GRAS) when ingested, GRAS status after inhalation is unclear. The aim of this review was to assess evidence from 38 reports on the adverse effects of flavored e-liquids on the respiratory system in both in vitro and in vivo studies published between 2006 and 2021. Data collected demonstrated greater detrimental effects in vitro with cinnamon (9 articles), strawberry (5 articles), and menthol (10 articles), flavors than other flavors. The most reported effects among these investigations were perturbations of pro-inflammatory biomarkers and enhanced cytotoxicity. There is sufficient evidence to support the toxicological impacts of diacetyl- and cinnamaldehyde-containing e-liquids following human inhalation; however, safety profiles on other flavors are elusive. The latter may result from inconsistencies between experimental approaches and uncertainties due to the contributions from other e-liquid constituents. Further, the relevance of the concentration ranges to human exposure levels is uncertain. Evidence indicates that an adequately controlled and consistent, systematic toxicological investigation of a broad spectrum of e-liquid flavors may be required at biologically relevant concentrations to better inform public health authorities on the risk assessment following exposure to EC flavor ingredients.
... Specifically, we argue flavor is a critical factor in the appeal of eCigs, as noted elsewhere (e.g., Baker et al., 2021b;Bernat et al., 2021;Pang et al., 2022;Ramamurthi et al., 2022). For example, one early study found, on average, individuals used three different types of e-liquid on a regular basis, and exclusive vapers switched flavors more frequently than those who concurrently vape and smoke (Farsalinos et al., 2013). In their profile of vapers, Dawkins et al. (2013) found individuals start using flavored eCigs because they wanted either a complete or partial alternative to smoking, due to curiosity, or because of a friend's recommendation. ...
Article
Full-text available
Thousands start smoking or vaping daily, despite long-standing efforts by public health authorities to curb initiation and use of nicotine containing products. Over the last 15 years, use of electronic nicotine delivery systems has increased dramatically, with a diverse range of products on the market, including pod-based, disposable, and refillable electronic cigarettes (eCigs). Originally intended for harm reduction and smoking cessation, eCigs may encourage nicotine use among never smokers, given the vast range of appealing flavors that are available. To better understand abuse liability and to facilitate appropriate regulations, it is crucial to understand the science of flavor, and flavor perception within the context of eCig use. Here, we (a) provide a brief primer on chemosensory perception and flavor science for addiction and nicotine researchers, and (b) highlight existing some literature regarding flavor and nicotine use, with specific attention given to individual differences in perception, and interaction between different sensory modalities that contribute to flavor. Dramatic increases in use of eCigs highlights the importance of flavor science in contemporary addiction research, both with regards to public health and regulatory efforts. Other recent work summarizes findings on flavored e-liquids and eCig use, but none have focused explicitly on chemosensory processes or flavor perception as they relate to appeal and use of such products. We argue flavor science needs to be considered as perceptual and behavioral phenomena, and not merely from analytical, toxicological and pharmacological perspectives; we help address this gap here.
... Exploratory moderation findings showed the negative association of flavor use and e-cigarette cessation appeared stronger for younger participants. This result might be explained by causal factors (e.g., e-cigarette flavors appeal more to younger than older adults; Harrell et al., 2017;Huang et al., 2017;Meernik et al., 2019;Zare et al., 2018) or noncausal reasons (e.g., younger and older adults may use e-cigarettes for different reasons-younger adults may be more likely to experiment or use e-cigarettes recreationally, whereas older adults may be more likely to use e-cigarettes as a temporary smoking cessation aid) (Chen, 2018;Farsalinos et al., 2013;Vu et al., 2019). In the current study, we did not assess tobacco users' intention to quit, which might help explain these different findings for young adult versus adult flavored e-cigarette users (Meernik et al., 2019;Vu et al., 2019). ...
Article
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. Using 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 for most products. 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.
... Participants expressed interest in ENDS as an alternative to tobacco cigarettes because of the enticing and customizable flavors of ENDS. This was consistent with a survey conducted by Farsalinos et al., which found that the most important factor for the maintenance of ENDS use was the variety of flavorings, which assisted with reduction of tobacco cigarette use [34]. However, most participants perceived ENDS as not beneficial because participants were more likely to try to decrease all nicotine products as part of their quit attempts. ...
Article
Full-text available
The prevalence of smoking among young adults aged 19–28 years old in the United States persists at rates of 14.3%. Young adults underutilize pharmacotherapy for smoking cessation, and the use of e-cigarettes has increased. We analyzed comments from online smoking-cessation support groups to understand young-adult smokers’ views of pharmacotherapy and e-cigarettes, to provide a more in-depth insight into the underutilization of pharmacotherapy. A qualitative analysis was performed on comments about pharmacotherapy and e-cigarettes from participants enrolled in online smoking-cessation support groups in 2016–2020. A codebook was developed with a deductive approach to code the comments, followed by thematic analysis. Eighteen themes were identified, with four dominant themes: interest, benefit, knowledge, and flavor. Participants expressed less interest in both nicotine-replacement therapy and e-cigarettes; moreover, they expressed unfamiliarity with and misconceptions about pharmacotherapy, and recognized the enticing flavors of e-cigarettes. Participants often felt e-cigarettes were not useful for smoking cessation, but the flavors of e-cigarettes were appealing for use. Participants had mixed opinions about the use of e-cigarettes for smoking cessation, but predominantly felt e-cigarettes were not useful for smoking cessation. The use of social media may be an effective way to address misconceptions about pharmacotherapy for smoking cessation and increase willingness to accept assistance.
... E-liquids (five 10-mlj bottles) will be supplied weekly for 4 weeks by centre staff; five bottles are always provided regardless of levels of use. Participants will be given time to try different flavours and nicotine strengths at baseline and be permitted to switch between flavours in accordance with documented vaping practices [15]. EC charging will be available at homeless cen- Procedure Figure 1 presents the study flow diagram and data collection at each time-point. ...
Article
Full-text available
Background and aims: Smoking is extremely common among adults experiencing homelessness but there is lack of evidence for treatment efficacy. E-cigarettes are an effective quit aid, but they have not been widely tested in smokers with complex health and social needs. Here we build on our cluster feasibility trial and evaluate the offer of an e-cigarette or usual care to smokers accessing a homeless centre. Design: Multi-centre two-arm cluster randomised controlled trial with mixed-method embedded process and economic evaluation. Setting: Homeless centres in England, Scotland and Wales. Participants: Adult smokers (18+ years; n= 480) accessing homeless centres and who are known to centre staff and willing to consent. Intervention and comparator: Clusters (n=32) will be randomised to either an e-cigarette starter pack with weekly allocations of nicotine containing e-liquid for 4 weeks (choice of flavours (menthol, fruit and tobacco) and strengths 12 mg/mL and 18mg/mL), or the usual care intervention which comprises very brief advice and a leaflet signposting to the local stop smoking service. Measurements: The primary outcome is 24-week sustained carbon monoxide validated smoking cessation (Russell Standard defined, intention-to-treat analysis). Secondary outcomes: i) Fifty percent smoking reduction (cigarettes per day) from baseline to 24 weeks; ii) 7-day point prevalence quit rates at 4-, 12- and 24-week follow-up; iii) changes in risky smoking practices (e.g. sharing cigarettes, smoking discarded cigarettes) from baseline to 4-, 12- and 24-weeks; iv) cost-effectiveness of the intervention; v) fidelity of intervention implementation; mechanisms of change; contextual influences and sustainability. Comments This is the first study to randomly assign smokers experiencing homelessness to an e-cigarette and usual care intervention to measure smoking abstinence with embedded process and economic evaluations. If effective, its results will be used to inform the larger scale implementation of offering e-cigarettes across homeless centres to aid smoking cessation.
Preprint
Full-text available
Background Although electronic cigarettes (e-cigarettes) appear to be effective in helping smokers to stop smoking, concerns about use of e-cigarettes among young people have led to restrictions on non-tobacco flavoured e-liquids in some countries. However, these restrictions could reduce the appeal of these products to non-smoking youth but could have unintended consequences for smokers and e-cigarette users (vapers). Methods In this qualitative study, we aimed to explore smokers’ and vapers’ opinions of unflavoured e-liquids and their beliefs about how they would be impacted by hypothetical e-liquid flavour restrictions. UK adult smokers and vapers trialled an unflavoured e-liquid instead of their usual nicotine product for four hours and completed a survey and an online interview. Results Using Interpretive Phenomenological Analysis and graphically presented data, we found differences in smokers’ and vapers’ opinions of unflavoured e-liquid. If only unflavoured, tobacco flavoured, and menthol flavoured e-liquids remained on the UK market, some smokers and vapers may be unaffected, but some may be at a greater risk of relapsing to smoking or continuing smoking. Despite wanting to protect children from the harms of vaping, there was disagreement about whether flavour restrictions would be an effective method. Conclusions The findings indicate a potential adverse impact on smoking rates if e-liquid flavour restrictions are implemented in the UK.
Article
Background Nowadays, cigarette smoking remains the leading cause of chronic disease and premature death, especially cardiovascular disease. As an emerging tobacco product, e-cigarettes have been advocated as alternatives to canonical cigarettes, and thus may be an aid to promote smoking cessation. However, recent studies indicated that e-cigarettes should not be completely harmless to the cardiovascular system. Aim of Review This review aimed to build up an integral perspective of cigarettes and e-cigarettes-related cardiovascular toxicity. Key Scientific Concepts of Review This review adopted the adverse outcome pathway (AOP) framework as a pivotal tool and aimed to elucidate the association between the molecular initiating events (MIEs) induced by cigarette and e-cigarette exposure to the cardiovascular adverse outcome. Since the excessive generation of reactive oxygen species (ROS) has been widely approved to play a critical role in cigarette smoke-related CVD and may also be involved in e-cigarette-induced toxic effects, the ROS overproduction and subsequent oxidative stress are regarded as essential parts of this framework. As far as we know, this should be the first AOP framework focusing on cigarette and e-cigarette-related cardiovascular toxicity, and we hope our work to be a guide in exploring the biomarkers and novel therapies for cardiovascular injury.
Article
Full-text available
Electronic cigarettes (e-cigs) are used by millions of adolescents and adults worldwide. Commercial e-liquids typically contain flavorants, propylene glycol, and vegetable glycerin with or without nicotine. These chemical constituents are detected and evaluated by chemosensory systems to guide and modulate vaping behavior and product choices of e-cig users. The flavorants in e-liquids are marketing tools. They evoke sensory percepts of appealing flavors through activation of chemical sensory systems to promote the initiation and sustained use of e-cigs. The vast majority of flavorants in e-liquids are volatile odorants, and as such, the olfactory system plays a dominant role in perceiving these molecules that enter the nasal cavity either orthonasally or retronasally during vaping. In addition to flavorants, e-cig aerosol contains a variety of by-products generated through heating the e-liquids, including odorous irritants, toxicants, and heavy metals. These harmful substances can directly and adversely impact the main olfactory epithelium (MOE). In this article, we first discuss the olfactory contribution to e-cig flavor perception. We then provide information on MOE cell types and their major functions in olfaction and epithelial maintenance. Olfactory detection of flavorants, nicotine, and odorous irritants and toxicants are also discussed. Finally, we discuss the cumulated data on modification of the MOE by flavorant exposure and toxicological impacts of formaldehyde, acrolein, and heavy metals. Together, the information presented in this overview may provide insight into how e-cig exposure may modify the olfactory system and adversely impact human health through the alteration of the chemosensory factor driving e-cig use behavior and product selections. © 2021 American Physiological Society. Compr Physiol 11:2621-2644, 2021.
Article
Full-text available
Background Cigarette smoking remains the leading cause of preventable morbidity and mortality in the United States. Despite overall declines in cigarette smoking, a high prevalence of smoking persists among certain subpopulations, including persons with mental illness. Methods Combined data from the 2009–2011 National Survey on Drug Use and Health (NSDUH) were used to calculate national and state estimates of cigarette smoking among adults aged ≥18 years who had any mental illness (AMI), defined as having a mental, behavioral, or emotional disorder, excluding developmental and substance use disorders, in the past 12 months. Results During 2009–2011, an annual average of 19.9% of adults aged ≥18 years had AMI; among these persons, 36.1% were current smokers, compared with 21.4 % among adults with no mental illness. Smoking prevalence among those with AMI was highest among men, adults aged <45 years, and those living below the poverty level; smoking prevalence was lowest among college graduates. During 2009–2011, adults with AMI smoked 30.9% of all cigarettes smoked by adults. By U.S. region, smoking prevalence among those with AMI was lowest in the West (31.5%) and Northeast (34.7%) and highest in the Midwest (39.1%) and South (37.8%), with state prevalence ranging from 18.2% (Utah) to 48.7% (West Virginia). Conclusions The prevalence of cigarette smoking is high among adults with AMI, especially for younger adults, those with low levels of education, and those living below the poverty level; the prevalence varies by U.S. region. Implications for Public Health Practice Increased awareness about the high prevalence of cigarette smoking among persons with mental illness is needed to enhance efforts to reduce smoking in this population. Proven population-based prevention strategies should be extended to persons with mental illness, including implementing tobacco-free campus policies in mental health facilities. Primary care and mental health-care providers should routinely screen patients for tobacco use and offer evidence-based cessation treatments. Given that persons with mental illness are at risk for multiple adverse behavioral and health outcomes, tobacco cessation will have substantial benefits, including a reduction in excess morbidity and mortality attributed to tobacco use.
Article
Full-text available
Background: Electronic cigarettes (ECs) have been marketed as an alternative-to-smoking habit. Besides chemical studies of the content of EC liquids or vapour, little research has been conducted on their in vitro effects. Smoking is an important risk factor for cardiovascular disease and cigarette smoke (CS) has well-established cytotoxic effects on myocardial cells. The purpose of this study was to evaluate the cytotoxic potential of the vapour of 20 EC liquid samples and a "base" liquid sample (50% glycerol and 50% propylene glycol, with no nicotine or flavourings) on cultured myocardial cells. Included were 4 samples produced by using cured tobacco leaves in order to extract the tobacco flavour. Methods: Cytotoxicity was tested according to the ISO 10993-5 standard. By activating an EC device at 3.7 volts (6.2 watts-all samples, including the "base" liquid) and at 4.5 volts (9.2 watts-four randomly selected samples), 200 mg of liquid evaporated and was extracted in 20 mL of culture medium. Cigarette smoke (CS) extract from three tobacco cigarettes was produced according to ISO 3308 method (2 s puffs of 35 mL volume, one puff every 60 s). The extracts, undiluted (100%) and in four dilutions (50%, 25%, 12.5%, and 6.25%), were applied to myocardial cells (H9c2); percent-viability was measured after 24 h incubation. According to ISO 10993-5, viability of <70% was considered cytotoxic. Results: CS extract was cytotoxic at extract concentrations >6.25% (viability: 76.9 ± 2.0% at 6.25%, 38.2 ± 0.5% at 12.5%, 3.1 ± 0.2% at 25%, 5.2 ± 0.8% at 50%, and 3.9 ± 0.2% at 100% extract concentration). Three EC extracts (produced by tobacco leaves) were cytotoxic at 100% and 50% extract concentrations (viability range: 2.2%-39.1% and 7.4%-66.9% respectively) and one ("Cinnamon-Cookies" flavour) was cytotoxic at 100% concentration only (viability: 64.8 ± 2.5%). Inhibitory concentration 50 was >3 times lower in CS extract compared to the worst-performing EC vapour extract. For EC extracts produced by high-voltage and energy, viability was reduced but no sample was cytotoxic according to ISO 10993-5 definition. Vapour produced by the "base" liquid was not cytotoxic at any extract concentration. Cell survival was not associated with nicotine concentration of EC liquids. Conclusions: This study indicates that some EC samples have cytotoxic properties on cultured cardiomyoblasts, associated with the production process and materials used in flavourings. However, all EC vapour extracts were significantly less cytotoxic compared to CS extract.
Article
Full-text available
Full text available with free acces at: http://www.la-press.com/evaluating-nicotine-levels-selection-and-patterns-of-electronic-cigare-article-a3858 Electronic cigarettes (ECs) are alternative-to-smoking nicotine delivery devices; consumers (commonly called vapers) use them in order to reduce or completely substitute smoking. The European Commission has released a proposal for a new Tobacco Product Directive that might reduce availability of nicotine-containing products, including ECs. In this study, the EC use patterns in subjects who have completely substituted smoking with EC use were examined by personal interviews. The study focused on nicotine levels used in order to achieve smoking cessation, reported benefits, associated side effects, and estimation of EC dependence compared with smoking. Participants were 111 subjects who had completely substituted smoking with EC use for at least 1 month. Smoking abstinence was validated by measuring blood carboxyhemoglobin levels. Nicotine levels at initiation of EC use, at time of smoking cessation, and at time of interview were recorded. Dependence potential was assessed by asking the first question of the Fagerström Test for Cigarette Dependence (time until smoking the first cigarette and until first use of EC in the morning) and questions about perceived past dependence on tobacco cigarettes and present dependence on EC. Forty-two percent of participants reported quitting smoking during the first month of EC use. Liquids with nicotine concentration >15 mg/mL were used by 74% of users at initiation of EC use, while 16.2% had to increase the initial nicotine levels in order to achieve complete smoking abstinence. Seventy-two participants (64.9%) reported that from the time of smoking cessation to the time of the interview (8 months median duration of EC use) they reduced the nicotine concentration they were consuming; however, only 12% of the total sample was using ≤5 mg/mL nicotine concentration at the time of the interview. Side effects were mild and temporary. The vast majority of participants reported better exercise capacity and improved olfactory and gustatory senses. Perceived EC dependenct was significantly lower compared to smoking. Nicotine levels appear to play an important role in achieving and maintaining smoking cessation in the group of motivated subjects studied. High nicotine-containing liquids were used while few mild and temporary side effects were reported. Proposals about regulation should consider the pragmatic use patterns of ECs, especially in consumers who have completely substituted smoking.
Article
Full-text available
Background: Electronic cigarettes (e-cigarettes) are becoming increasingly popular with smokers worldwide. Users report buying them to help quit smoking, to reduce cigarette consumption, to relieve tobacco withdrawal symptoms, and to continue having a 'smoking' experience, but with reduced health risks. Research on e-cigarettes is urgently needed in order to ensure that the decisions of regulators, healthcare providers and consumers are based on science. Methods ECLAT is a prospective 12-month randomized, controlled trial that evaluates smoking reduction/abstinence in 300 smokers not intending to quit experimenting two different nicotine strengths of a popular e-cigarette model ('Categoria'; Arbi Group Srl, Italy) compared to its non-nicotine choice. GroupA (n = 100) received 7.2 mg nicotine cartridges for 12 weeks; GroupB (n = 100), a 6-week 7.2 mg nicotine cartridges followed by a further 6-week 5.4 mg nicotine cartridges; GroupC (n = 100) received no-nicotine cartridges for 12 weeks. The study consisted of nine visits during which cig/day use and exhaled carbon monoxide (eCO) levels were measured. Smoking reduction and abstinence rates were calculated. Adverse events and product preferences were also reviewed. Results: Declines in cig/day use and eCO levels were observed at each study visits in all three study groups (p<0.001 vs baseline), with no consistent differences among study groups. Smoking reduction was documented in 22.3% and 10.3% at week-12 and week-52 respectively. Complete abstinence from tobacco smoking was documented in 10.7% and 8.7% at week-12 and week-52 respectively. A substantial decrease in adverse events from baseline was observed and withdrawal symptoms were infrequently reported during the study. Participants' perception and acceptance of the product under investigation was satisfactory. Conclusion: In smokers not intending to quit, the use of e-cigarettes, with or without nicotine, decreased cigarette consumption and elicited enduring tobacco abstinence without causing significant side effects. Trial registration: ClinicalTrials.gov NCT01164072 NCT01164072.
Article
Full-text available
Introduction: Electronic cigarettes (e-cigarettes) are a means of recreational nicotine use that can potentially eliminate the need to smoke tobacco. Little is known about the prevalence of use or smokers' attitudes toward e-cigarettes. This study describes use of and attitudes toward e-cigarettes in Britain. Methods: Respondents from three surveys were recruited from a panel of adults in Britain. Preliminary online and face-to-face qualitative research informed the development of a smokers' survey (486 smokers who had used e-cigarettes and 894 smokers who had not). Representative samples of adults in Britain were then constructed from the panel for population surveys in 2010 (12,597 adults, including 2,297 smokers) and 2012 (12,432 adults, including 2,093 smokers), generating estimates of the prevalence of e-cigarette use and trial in Great Britain. Results: Awareness, trial, and current use increased between 2010 and 2012; for example, current use more than doubled from 2.7% of smokers in 2010 to 6.7% in 2012. The proportion of ever-users currently using e-cigarettes was around one-third in both years. In 2012, 1.1% of ex-smokers reported current e-cigarette use, and a further 2.7% reported past use. Approximately 0.5% of never-smokers reported having tried e-cigarettes. Conclusions: While we found evidence supporting the view that e-cigarette use may be a bridge to quitting, we found very little evidence of e-cigarette use among adults who had never smoked. British smokers would benefit from information about the effective use, risks, and benefits of e-cigarettes, as this might enable the use of e-cigarettes to improve public health.
Article
Background Electronic cigarettes (e-cigarettes) can deliver nicotine and mitigate tobacco withdrawal and are used by many smokers to assist quit attempts. We investigated whether e-cigarettes are more eff ective than nicotine patches at helping smokers to quit.
Article
As elsewhere, in South Korea electronic cigarettes (e-cigarettes) are marketed, in part, as a smoking cessation aid. We assessed the prevalence of e-cigarette use among Korean adolescents and the relationship between e-cigarette use and current (past 30-day) smoking, cigarettes/day, attempts to quit conventional cigarettes, and ceasing to use cigarettes. Data from the 2011 Korean Youth Risk Behavior Web-based Survey of 75,643 students aged 13-18 years were analyzed with logistic regression. A total of 9.4% (8.0% ever-dual users who were concurrently using e-cigarettes and smoking conventional cigarettes and 1.4% ever-e-cigarette only users) of Korean adolescents have ever used e-cigarettes and 4.7% were current (past 30-day) e-cigarette users (3.6% dual users and 1.1% e-cigarettes only). After adjusting for demographics, current cigarette smokers were much more likely to use e-cigarettes than were nonsmokers. Among current cigarette smokers, those who smoked more frequently were more likely to be current e-cigarette users. The odds of being an e-cigarette user were 1.58 times (95% confidence interval, 1.39-1.79) higher among students who had made an attempt to quit than for those who had not. It was rare for students no longer using cigarettes to be among current e-cigarette users (odds ratio, .10; confidence interval, .09-.12). Some Korean adolescents may be responding to advertising claims that e-cigarettes are a cessation aid: those who had made an attempt to quit were more likely to use e-cigarettes but less likely to no longer use cigarettes. E-cigarette use was strongly associated with current and heavier cigarette smoking.
Article
Electronic nicotine delivery systems (ENDS) have been gaining in popularity. The few prevalence studies in adults have found that most ENDS users are current or former smokers. The objectives of this study were to estimate the prevalence of ENDS usage in adolescents, and examine the correlates of use. Self-administered written surveys assessing tobacco use behaviors were conducted in multiple waves as part of a larger intervention study in two large suburban high schools. The prevalence of past-30day ENDS use increased from 0.9% in February 2010 to 2.3% in June 2011 (p=0.009). Current cigarette smokers had increased odds of past-30day ENDS use in all study waves. When adjusted for school, grade, sex, race and smoking status, students in October 2010 (Adjusted OR 2.12; 95% confidence interval (CI): 1.12-4.02) and June 2011 (Adjusted OR 2.51; 95% CI: 1.17-4.71) had increased odds past-30day ENDS use compared to February 2010. The prevalence of ENDS use doubled in this sample of high school students, and current cigarette smoking is the strongest predictor of current use. Continued monitoring of ENDS is needed to determine whether it increases the likelihood of cigarette smoking initiation and maintenance in youth.
Article
Electronic cigarettes (e-cigarettes) can deliver nicotine and mitigate tobacco withdrawal and are used by many smokers to assist quit attempts. We investigated whether e-cigarettes are more effective than nicotine patches at helping smokers to quit. We did this pragmatic randomised-controlled superiority trial in Auckland, New Zealand, between Sept 6, 2011, and July 5, 2013. Adult (≥18 years) smokers wanting to quit were randomised (with computerised block randomisation, block size nine, stratified by ethnicity [Māori; Pacific; or non-Māori, non-Pacific], sex [men or women], and level of nicotine dependence [>5 or ≤5 Fagerström test for nicotine dependence]) in a 4:4:1 ratio to 16 mg nicotine e-cigarettes, nicotine patches (21 mg patch, one daily), or placebo e-cigarettes (no nicotine), from 1 week before until 12 weeks after quit day, with low intensity behavioural support via voluntary telephone counselling. The primary outcome was biochemically verified continuous abstinence at 6 months (exhaled breath carbon monoxide measurement <10 ppm). Primary analysis was by intention to treat. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12610000866000. 657 people were randomised (289 to nicotine e-cigarettes, 295 to patches, and 73 to placebo e-cigarettes) and were included in the intention-to-treat analysis. At 6 months, verified abstinence was 7·3% (21 of 289) with nicotine e-cigarettes, 5·8% (17 of 295) with patches, and 4·1% (three of 73) with placebo e-cigarettes (risk difference for nicotine e-cigarette vs patches 1·51 [95% CI -2·49 to 5·51]; for nicotine e-cigarettes vs placebo e-cigarettes 3·16 [95% CI -2·29 to 8·61]). Achievement of abstinence was substantially lower than we anticipated for the power calculation, thus we had insufficient statistical power to conclude superiority of nicotine e-cigarettes to patches or to placebo e-cigarettes. We identified no significant differences in adverse events, with 137 events in the nicotine e-cigarettes group, 119 events in the patches group, and 36 events in the placebo e-cigarettes group. We noted no evidence of an association between adverse events and study product. E-cigarettes, with or without nicotine, were modestly effective at helping smokers to quit, with similar achievement of abstinence as with nicotine patches, and few adverse events. Uncertainty exists about the place of e-cigarettes in tobacco control, and more research is urgently needed to clearly establish their overall benefits and harms at both individual and population levels. Health Research Council of New Zealand.