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.
“Is the e-cigarette good for me, does it have any impact on my health?” – This talk is for those asking these questions.
E-Cigarettes switching: Evidence for positive health effects
Riccardo Polosa starts by acknowledging his staff for the last three or four years, that he qualifies “a dedicated team of people who believed it was time to talk about benefits“.
Against all beliefs, The safety of long term EC use is a legitimate question and can be answered. The researcher does not paint this oppressive picture others are doing with the e-cigarette. He does not exclude that the risks exist because of some harmful or potentially harmful molecules contained in the aerosol but the risk also exists with any other products we drink or eat.
The question can be answered:
- by large prospective studies of well-characterized EC users (impractical, costly),
- or, alternatively, by extrapolating responses to e-vapour in vitro cell lines and/or in animal models (does not directly apply to real-life situation)
By well-characterized, the researcher explains that as ex-smokers, the panel that is chosen to carry out prospective studies, already have a damage in their body that is sometimes not stopping after they quit smoking but is only slowed down while progressing. Quitting smoking does not exclude the occurence a heart attack which is not due to smoking cessation but to smoking. Prospective studies are expensive to conduct and most of the studies carried out in vitro are irrelevant to the daily condition of a vaper.
Other means to address the question are:
- by detecting early changes of subclinical injury with highly sensitive functional tests (“healthy” smokers),
- Or, alternatively, by documenting changes with more robust and validated investigational tools (EC users with pre-existing disease).
The idea is to measure over time what happens to smokers when they stop smoking. This can be done with ex-smokers or vapers with pre-existing diseases. “But in any case we will do acute studies that are never predictive of what happens in future“, says the clinician, in echo of the comments of his colleague and co-author, Konstantinos Farsalinos.
Benefits on the cardiovascular system
The researchers selected regular daily vapers suffering from hypertension and followed them with time and similarly followed some people who kept smoking. In the study, he precises, not everybody quit smoking, some dual users remained but the overall consumption of regular cigarettes decreased with a residual tobacco consumption du to dual users.
Their average systolic blood pressure, after switching to vaping for 12 months, significantly decreased by 10 mm Hg. Such a reduction is more that can be achieved with an hypertensive drug. This is accompanied by an overall increase of the level of good control (all the pertinent parameters indicating normal functioning) from 20% to about 45%. This means that the double of the hypertensive patients improved their control of blood pressure by switching to vaping.
Limited post-cessation weight gain
The gain in weight when switching to vaping is present but limited (black bars), only less than 4% body weight compared to baseline after 6 months, which is “less than what people generally gain during Christmas holidays“, ironizes the researcher. The post-cessation weight gain provided by literature (blue bars) is significantly higher when quitting smoking by other means, including cold turkey. The researcher also indicates that the effect on body weight gain is also shorter over time because after one year, a decrease of weight is already observed with e-cigarettes.
R. Polosa gives his observations with regard to his findings: People who switch to vaping, he says, are not putting on too much weight, which motivates them to practice physical exercise and, in turn, facilitates the loss of weight.
Benefits on the respiratory system
Asthmatics have very twitchy airways, explains the researcher whose main field of action has been to study this disease, and they are a good model to show whether exposure to e-vapor brings asthma attacks.
His study finds that people who quit smoking are improving some measures of spirometry, as an evaluation of their better lung function. Cough also, tends to disappear one year after switching. The level of improvement monitored with spirometry, which seems little, the equivalent of a can of soda, is actually higher compared to what is obtained with bronchodilators. R. Polosa recalls that ECLAT has been following people for two years, which already is “long-term” compared to other studies over one to three months.
Exacerbations are a problem for asthmatics. His study was carried out on mild to moderate asthmatic smokers (for ethical reasons) who switched to vaping. Those patients, recalls the specialist, only have a few (<3) exacerbations in a year, which makes the study of improvements very complicated. However, 50% of patients improved with lower occurrences of asthma exacerbations. Two patients relapsed back into smoking and showed a recurrence of asthma exacerbation.
After summarizing his main findings (improved lung function, respiratory symptoms, subjective/objective asthma outcomes, improved quality of life) R. Polosa mentions that improvements are also reported in dual users. And as an answer to the questions that are generally addressed, he reassures vapers with the use of e-cigarettes and suggests them as an helpful alternative to cigarettes, even in smokers with asthma/COPD.
Optimizing the benefits rather than minimizing the risks
To conclude with his presentation, R. Polosa proposes actions to be oriented towards the optimization of the benefits rather than minimizing the risks, which goes through the innovation of the products, making more studies on toxicology and integrating toxicology with innovation (number of coils, vaping machines). These are little fits that can be achieved to minimize the risk without the need of tobacco product directives.
The debate is about limiting Direct Lung (DL) Inhalation as one way of minimizing the risk linked to vaping, he says. We know that an e-cigarette is a highly innovative product compared to a tobacco company combustible one and that many vapers, when purchasing a new model, expect to exploit most of its power range for the fun of it.
R. Polosa’s research perspectives
The researcher evokes his long-term study (currently 4 years) of vapers who have never smoked. He shows high-resolution CT (computerized tomography) scans of two patients, vapers for 4 years (4-6 ml nicotine e-liquid/day), that, according to his diagnostic are “normal”. Unfortunately the comparison with 4-year smokers is not easy but if his team manages to find such candidates, this would bring interesting results, says R. Polosa who declares, alluding to Jean-François Etter, that none of his vaper-but-non-smoker candidates has turned to smoking, so far. A last comment by Konstantinos Farsalinos warns that CT-scans are very different from X-ray images that cannot be used as a diagnostic tool in the case of vaping, in order to discourage people from self-diagnozing on the internet.