Presented for several years as a less harmful alternative to traditional cigarettes, there electronic cigarette remains at the center of a debate public health. There nicotine has long attracted attention, due to its addictive power and its role in addiction. But the American study conducted by the professor’s team Ahmad Besaratinia shows that the question cannot be reduced to this substance alone. In the vapingthe exposure also depends on the composition of the liquidof the flavors usedfrom the power of the device and consumption habits.
The researchers worked on a sample of 83 peopledistributed between 35 vapers, 24 smokers of traditional cigarettes and 24 people who do not consume tobacco or electronic cigarettes. They took cells from the inside of the cheek, because the mouth is the first tissue directly exposed to the inhaled aerosol. These cells were then analyzed by RNA sequencing, a method that makes it possible to observe gene activity and detect biological modifications associated with a given exposure.
The results show that vapers show significant changes in the expression of their genes compared to non-users. The study identifies 3,124 genes whose activity is modified in vapers. Among smokers, 2,180 genes are concerned.
The main contribution of this study lies in factor analysis which explain these changes. The researchers did not just compare vapers, smokers and non-users. They also looked at the amount of liquid consumed, exposure to nicotine, duration of vaping, type of device used and e-liquid flavors. This approach allows us to better understand why the effects observed in vapers are more variable than those observed in smokers.
Aromas, much more than a question of taste!
THE aromas appear to be an important factor in the differences observed between vapers. The study specifies that 42.9% of the vapers monitored used several flavors, 34.3% fruity flavors, 14.3% sweet flavors and 8.6% menthol flavors. The most marked changes concern users of several flavors, with 2,009 genes affectedor 64.3% of modified genes among vapers. Fruity aromas come next, with 970 genes concerned, or 31% of the modifications observed. Sweet flavors are associated with 92 modified genes and menthol flavors with 27 genes, lower levels in this cohort, without the study allowing them to be considered as having no effect. Researchers were interested in these modifications because they concern genes involved in the protection and proper functioning of cells. Disturbances of these mechanisms can, in the long term, weaken tissues and promote the development of certain diseases, notably cancersof the inflammatory diseases or even respiratory pathologies.
The type of device also changes the situation
The type of device used also seems to influence the magnitude of the changes observed. Among the 35 vapers studied, 60% used third generation devices, often called “mods” or “tanks”, while 28.6% alternated between several types of devices. The researchers observed that genetic modifications were mainly present in these two categories. Users of third generation devices were associated with 1,747 genes modifiedcompared to 1,367 for those using several models. Conversely, no significant changes were observed among the rare users of first generation devices, “cigalike” typeor second generation, of “vape pen” typea result that the authors attribute more to the low number of participants in these categories than to the absence of effect of these measures. These observations suggest that the latest and greatest devices could be associated with more marked biological effectsdue in particular to their power, their heating temperature and the quantity of aerosol produced, they conclude.
