Jacques Le Houezec, Konstantinos Farsalinos, Jean-François Etter and Riccardo Polosa were on stage at Vapexpo 2016 to highlight current trends in e-cigarette research.
Konstantinos Farsalinos comes back on the recent scientific publications published in 2016 that shacked the opinion. As always, he tries to debunk science. One of his first observations is that there is an increasing number of publications dealing with the e-cigarette compared to the previous years. And among those publications, an increasing number also report misleading information.
In his talk, he will address chemical studies (aldehydes, dry puffs, outdated devices, flavorings), toxicological studies (dose of exposure), clinical studies (focus on irrelevant animal studies) and examine the different means through which e-cigarettes can be harmful.
Aldehydes: Formaldehyde and acrolein
Going back to 2013, scientists were aware that aldehydes (among which formaldehyde) were emitted by e-cigarettes. In this continuity, the same researchers demonstrated the next year that the voltage is playing an important role in the emission of aldehydes. Furthermore, the devices that were used for such studies are outdated compared to what vapers are using at the time the publication is released to public.
In the New England Journal of Medicine Letter, the authors calculated that over a lifetime, cancer risk with using e-cigarette could raise by 5-15 fold compared to the risk for regular smokers. Dr Farsalinos and his team addressed this question and identified that dry puffs were probably the cause of such high levels.
The researcher does not exclude the presence of aldehydes in e-cigarette emissions but dry puffs are peculiar conditions that generally do not happen when vaping, or at least that vapers can easily identify and can avoid.
The association between device power and aldehyde concentration was established recently by a team in Italy which confirm that the risk of developing cancer is much less than whas was initially thought. Furthermore, the relationship is not linear between the presence of aldehydes and power, which means that at the time vapers realize that something is changing in the taste of vapor, the levels are still very low.
The research team leaded by K. Farsalinos decided to replicate the original study by M. Goniewicz and to include humans in the protocol, the sole detector able to identify, with his taste, the occurence of dry puffs. They gradually increased the voltage in order to initiate dry puffs and asked the participant their impressions regarding the taste. They found that starting at 4.0 V, dry puffs may occur with the CE4 they were using, setting the limit of normal use until 4.0 V.
Liquid consumption was measured depending on the voltage and the authors found a positive correlation between the two. The observation that makes the researcher at this point is that increasing the voltage of a device drastically increases the risk by combining the non-linearity effect on aldehyde production and the exposure to more harmful compounds due to the larger volume of e-liquid consumed: they found that the levels are 7 to 8 times higher at 5.0 V compared to 4.2 V.
The danger upon exposure to formaldehyde has to be relativized, however, since the compound is found everywhere in our environment. The WHO has set the upper limit of formaldehyde in clean indoor air to 2000 μg/day, which is only three times lower than what inhales a vaper in Farsalinos’ experiment.
The orator recalls of the Harvard study about diacetyl and acetyl propionyl. He notices that the authors failed to mention that diacetyl was also present in tobacco smoke and has never posed to smokers any health safety issue at this level of exposure.
The differences observed in emitted diacetyl is due to the nature of the e-liquid itself and, especially, the flavorings that are combined to obtain the right taste. On this point, the author believes that such harmful compounds must be removed completely from e-liquids since some substitutes exist with a lower toxicity.
K. Farsalinos comes back on a recent study carried out on mice models that claimed the e-cigarette, through nicotine, could cause COPD. He ironises on the difference between mice and humans, especially from a metabolic point of view. Mice are much more efficient at metabolizing nicotine compared to humans and the degradation product (cotinine) is also eliminated at a much faster rate. Hence comparing mice to humans, in this field, is not realistic.
The effect of nicotine on blood vessels was also reviewed by the specialist. In vitro experiments generally expose the cells to levels that should be lethal to a normal adult, he explains.
A few studies addressed asthma but ignored that Ricardo Polosa carried out clinical studies that showed “collateral benefits” from vaping on human health.
In the case of aortic stiffness reported from a conference presentation by the Sun, in England, K. Farsalinos recalls that the acute conditions of the study are not compatible with relevant observation and that nicotine is no more harmful than caffeine, in fact. It is not surprising that false positive results are obtained in such bad conditions, believes the researcher. The same results are observed when nicotine gums are given to patients and also when they are given coffee.
The cardiologist recalls that he measured improvements in the heart function after four weeks of smoking cessation, which is the normal case when avoiding acute effect of nicotine exposure. He recalls that in no way this could be taken into consideration for evaluating long-term effects of vaping. The benefits of vaping on the heart function are pointed out from R. Polosa’s ECLAT survey on quitters and reducers.
The debate on nicotine is, by itself misleading
What appears important in K. Farsalinos’ studies, is that increasing the consumption of liquid is increasing the risk. It is for example what happens with new patterns, especially direct-lung pattern of use.
Compared to mouth-to-lung vaping, one direct-lung puff consumes 5 times more e-liquid. This pattern is generally associated to lower nicotine levels than traditional vaping style, to reduce irritation because of the higher consumption of liquid.
The researcher recalls Paracelsus principle of toxicity:”the amount of exposure, the dose, defines the toxicity”. Reducing the nicotine level but increasing the consumption is useless with regard to the nicotine, as demonstrated by Jean-François Etter when studying cotinine levels. J.-F. Etter qualified this effect a “compensation mechanism” for nicotine. In revenge, increasing e-liquid consumption exposes to more toxins. Hence, DL inhalation is a more risky pattern than MTL vaping, wanted to recall the clinician for the sake of clarity.
Jacques le Houezec mentions that there is currently a movement among e-liquid manufacturers and among the vapers, themselves, to reduce nicotine strength. The obvious issue is to get exposed to more toxins but the tobacco expert recalls that the risk is also to relapse into smoking.
Questions to K. Farsalinos
“What are the next steps in your research?”
The researcher reveals they have carried out a study on metals emitted from tank atomizers. In this study, they compared the emission of metals from tank atomizers and (disposable) cigalikes where the e-liquid is stored in contact with a metallic cartomizer during months before use which increases the risk of corrosion in the device.
Their results indicate that the levels of metals in emitted vapor were in the range of part per billion (ppb), meaning they are extremely small.
Aldehydes are addressed by his research team and also the comparison with the new harm reduction products proposed by tobacco companies like the IQOS. This is important, he thinks, to address the two different devices, e-cigarette and tobacco heating systems, that are “sold” as harm reduction products to smokers willing to stop smoking.
Finally, the Eurobarometer data are exploited again with a focus on daily e-cigarette users. A publication written in collaboration with Jacques Le Houezec.
“Could the fact that vapers try to reduce their nicotine level be pushed by the maximum nicotine strength defined by the TPD?”
K. Farsalinos believes that current e-cigarette models are efficient enough at delivering nicotine and may allow smokers to transition to vaping. As an illustration, the specialist says that twice as much nicotine can be delivered with ten puffs of an e-cigarette as with one tobacco cigarette .
In return, K. Farsalinos ask the public to remember when they started vaping, how much they consumed of e-liquid and to compare the numbers with their actual consumption. From his observations, the volume is likely three times, now. And this increase is driven by the new trends impulsed by the vaping industry. New vaping patterns like DL inhalation add other satisfaction levels to vapers after their transition from smoking with MTL, but this DL inhalation pattern is not needed to stay off cigarettes, it’s pure pleasure.
K. Farsalinos observe that the strength he vapes, 18 mg/ml, could no longer be found in the stands of the Vapexpo event. And this is the strength he has been vaping since he started with e-cigarettes.
The Vaping Post already identified the overall decrease of the offer in nicotine strength as a potential public health issue if this tendency is maintained by harsh regulations that make it expensive and burdensome to notify and register a full range of nicotine strengths for each flavor.
To go further on the marketing of nicotine with new vaping patterns: