the scientific truths about vaporettes – L’Express

The reason is obvious. “The combustion of cigarettes produces tar, responsible for cancers – lungs, larynx, bladder, etc. -, and carbon monoxide, linked to various cardiovascular disorders, including myocardial infarctions”, summarizes Professor Gérard Dubois, member of the National Academy of Medicine and professor emeritus of public health. This is not the case with the vaporette which simply heats a dilution medium (propylene glycol and/or vegetable glycerin), nicotine and different aromas. “Propylene glycol is considered so safe that it is authorized to produce smoke and fog in shows,” explains Professor Dubois. There remains nicotine which, although it is extremely addictive, is not carcinogenic in itself, contrary to what 80% of French people think.

But how much less toxic is vaping? “We should also not believe that it is harmless or that non-smokers can try it without risk,” emphasizes Professor Thomas. Studies have shown that certain toxic and carcinogenic chemicals present in cigarette smoke are found in vaporizer smoke, although at much lower levels. “These include nicotine degradation products, such as nitrosamines, but as the liquids are 99.6% purified, there are 200 times less than in a cigarette,” specifies tobacco specialist Bertrand Dautzenberg. with formaldehyde, we detect 0.03 to 0.05 mg – compared to 0.1 mg with a cigarette -, except when the liquid burns, in this case, the levels are close to those of cigarettes. On the other hand, when liquids are replaced by oils, vitamin E, THC or CBD, tragedies can occur, as was the case in the United States in 2019. “There were around fifty dead, but it was a misuse which has nothing to do with vaporettes”, sweeps away Professor Dubois. The doctor also puts aside “heated tobacco” devices, similar to vaping, but which are in reality much closer to real cigarettes in terms of health risk.

However, is the vaporette “95% less harmful than cigarettes”, as vaping defenders claim? “This figure came out of nowhere and has no scientific basis to date, it comes from a report from August 2015 which cites “an expert estimate” based on another report which itself is based on a 2014 study which… Never mentions this 95%! All this is based on nothing other than a non-reproducible estimate, 10 years old and produced barely 10 years after the invention of the product in question”, sweeps away Professor Loïc Josseran, president of ACT and medical researcher. in public health at the University of Versailles Saint-Quentin-en-Yvelines.

To affirm that vaporizing is 95% less harmful than cigarettes, scientists would need to follow vapers who have never consumed cigarettes for forty years in order to compare them to non-smokers or “pure smokers”. However, on the one hand, the product has only been used massively for ten years. On the other hand, today, 55.5% of vapers still smoke cigarettes, while the remaining 45% are ex-smokers. It is therefore difficult to distinguish the effects linked to vaping from those of cigarettes. Not to mention that the vaping device is not a unique or standardized object. Some are disposable, others have different draws and resistances. There are also many flavors. “Such research is complex to set up, would be very expensive, and would be difficult to finance,” adds Professor Thomas. An investment that health authorities are not always ready to make.

In the meantime, scientists are trying to discover weak signals by carrying out experimental studies, in the laboratory, on cells or animals. They then sometimes need to force the line. Thus, a study published in the journal of Proceedings of the American Academy of Sciences, in 2018, claimed that exposure to vapor smoke could degrade the DNA of cells in the hearts, lungs and bladders of mice. Except that the small 20-gram mammals were literally gassed, since they were exposed to 1920 milligrams of nicotine in just three months. That’s the equivalent of ten years of vaping. The results of this work were, at the time, strongly criticized.

A team from the Keck School of Medicine, for its part, published a more serious study, in 2021, in the journal Scientific Reports. This work suggests that vaping could cause undesirable biological changes and lead to the development of various cardiovascular and respiratory diseases, and even cancer. Their latest experiment, published in 2023 in Nicotine and Tobacco Research, suggests that vaping is associated with damage to the DNA of cells present in the mouth. “Users of pod e-cigarettes (like Juul) and sweeter products had the highest levels of DNA damage compared to non-users,” says Ahmad Besaratinia, professor of public health at the Keck School of Medicine. The concentration of nicotine smoked did not influence the results.

“Some will tell you that these experiments which look for weak signals are carried out in an aberrant manner. This is sometimes the case, with studies which heat e-liquids until they burn and inevitably release toxic compounds , notes Professor Daniel Thomas. But between them and the anti-vapes who highlight the worst results without making a distinction between what is admissible or not, there can be bad faith on both sides. Even when wanting to be the as objective as possible, it is not always easy to know which study is credible.”

According to Loïc Josseran, one of the outstanding questions concerns aromas, of which there are thousands. “Research suggests that they could cause neurological damage and heart rhythm disturbances, or even a thickening of the respiratory tree,” he underlines, citing a scientific study published in 2021 in Pharmacology & Therapeutics. This work points to “at least 65 aromatic ingredients”, the most worrying of which is cinnamaldehyde (cinnamon flavor), followed by vanillin and ethylvanillin (vanilla), menthol (mint), ethylmaltol (candy, pop -corn or cotton candy), benzaldehyde (almond) and linalool (fresh smell of mint aroma). In a press release published in February 2023, the CNCT also came out in favor of banning flavors. “Indeed, there are some aromas for which toxicity at the cellular level has been demonstrated,” confirms Daniel Thomas. “But it is not so much their toxicity as their capacity to trap adolescents that concerns me.” He is simply campaigning for the removal of confectionery flavors with childish names and sweet tastes. In its sights, like that of the CNCT, the ACT and the Academy of Medicine: puffs, these disposable electronic cigarettes which target the youngest.

It remains to be seen whether the vaporette can make it possible to give up tobacco. There, the searches are more precise. Two studies from the review Cochrane, the reference in the matter, show that it is the most effective smoking cessation device. For Bertrand Dautzenberg, as well as for Professor Dubois, the debate is settled, especially since these studies provide a “high” level of proof, in other words, a result close to certainty. “The debate on vaping pits two camps against each other, one which considers the vaporette as a weapon to help smokers quit tobacco, the other which worries that it could convert young non-smokers to nicotine. However, these two positions could be combined intelligently,” summarizes Daniel Thomas. To reconcile them, one of the solutions could be to assimilate vaporettes to medical devices – as in Austria and Norway – and make them accessible only in pharmacies, and no longer in tobacco shops or “vapostores”. which do not, or insufficiently, apply the ban on sales to minors. “Because the best cigarette is the one you don’t smoke, whatever it is,” recalls Professor Dubois.