E-Cigarettes : An alternative to smoking or a modern hazard...?

E-Cigarettes: An alternative to smoking or a modern hazard...?

Asma AIT SAID

It is a fact universally acknowledged that smoking is a damaging act to most of the organs of the human body and is a crucial risk factor for a countless number of fatal diseases. In the process of overcoming the addiction to smoking, many solutions were presumed to be relatively effective. Among them, electronic cigarettes take an important place as they are included in the family of Nicotine Replacement Therapy (NRT). Along with the improvement of these questionable devices, their use had exploded in the previous decade; especially in countries of higher incomes, namely the U.K., the U.S.A., Australia and many Asian countries. The category that seems to be the most concerned is the youth. But even adults seem to develop an addiction to electronic cigarette use. Several surveys have reported a number of people who have never been tobacco-smokers and yet became users of e-cigs after a first try; others had even relapsed after complete withdrawal. They however included previous smokers of conventional cigarettes mostly. Therefore, public health experts doubt the efficacy of these devices and their contribution to smoking cessation, thus creating a vibrant controversy in public health. In this short review, we will try to dis- cuss the actual components of electronic cigarettes, the extent of their efficacy and their authenticity of being a safe substitute to conventional cigarettes. Further information concerning the most recent studies and experiments will be analyzed along the article.

Definition and mechanisms of action

Originally created to resemble conventional cigarettes, E-cigarettes, also known as E-cigs, are electromechanical devices provided with a system that emits vaporized nicotine among other substances inhaled by the user.

             The consumer is thus ex- posed to all of the components present in the e-smoke. The process by which the e-smoke is made is pretty simple. Centered by an electronic circuit, the tool consists of a cartridge filled with a flavored liquid combined with a heating element or an atomizer, a sensor and a rechargeable battery.

 Either by pushing a button or inhaling, the sensor receives a signal and activates the atomizer that heats and aerosolizes the e-liquid in the reservoir converting it to a vapor that simulates tobacco smoke without any combustion occurring as it is tobacco free. The vapor is then inhaled or ‘’vaped’’ by the user through the drip tip or the mouthpiece.

E-liquid components

The components of the e-liquid are the principle root of the ambiguity concerning the side effects of using e-cigs, most of them are found in food, pharmaceutical and cosmetic products. Although electronic cigarettes are quickly evolving and further generations are still appearing, the different brands all share the same main components which are: Nicotine (although some e-cigs are called, or so-called, nicotine free), Propylene Glycol or Glycerol, and different types of Flavorings. Many other constituent elements have also been determined. Their biological potentials are further discussed.

- Nicotine: a highly addictive substance. The concentration of the nicotine delivered to the vascular system is related to the intensity of the puffs taken by the users. The stronger the puff is, the higher nicotinemia gets and could even reach similar levels of conventional cigarettes! Some of the e-cigs labeled nicotine free have been proven to actually contain nicotine and the concentrations referred to in the labels were found to be incompatible with the actual doses in the e-liquid.

- Propylene Glycol and/or Vegetable Glycerin or Glycerol: diluted in water, they represent the main component of the liquid and play a role in preserving the moisture in the cartridge and producing a visible aerosol.

             - Flavorings: electronic cigarettes include a astonishing number of characterized flavors that could be very enticing to the youth and especially to non-smokers. Tobacco is generally the flavor first picked at the start, but the other flavors such as mixed fruit, alcohol, soda and candy seem to be taking place.

             - Other compounds: many of the toxic elements present in tobacco cigarettes were shown to exist in e-cigs but in much lower levels including: metals such as tin, lead, nickel, arsenic, etc. tobacco-specific nitro- samines, carbonyls which are mainly obtained from the thermal degradation of the main substances pres- ent in the liquid.

The side effects of the components on human health

Endless debates, initiated by numerous surveys and clinical studies, argue the safety or hazardousness of such products on human health.

The effects of e-cigs on the human body de- pend on the state of the user and whether he/she is a current, a previous or a non-smoker of convention- al cigarettes. The latter users seem to reveal more threatening side effects than the two former categories. In fact, subjects who have never been exposed to tobacco smoke develop a high dependency due to the nicotine delivered in the aerosol.

In addition to being an addictive substance; nicotine present in the e-cigs -similarly to that of cigarette smoke- is responsible for many negative systemic effects, starting with an irritation and burning sensation in the throat, sialorrhea, nausea and abdominal pain; to inducing tachycardia by causing an important release of cathecholamines and producing hyperglycemia due to an increase in fatty acids blood level. Despite these side effects, recent data do not show an increase in the risk of cancer or cardio-pulmonary disease with chronic exposure to nicotine without tobacco smoke¹.

In regard to the other components of the e-liquid, clinical experiments assessed the consequences of long-term exposure and proved them to be potentially deleterious and even carcinogenic1, 2. The toxicity of these substances lies in their ability to convert to pernicious chemicals when certain conditions are at hand, inter alia, the battery voltage and the temperature of the e-liquid. For instance, Propylene oxide -presumed to be a human carcinogen- is the product of the composition of propylene glycol that is already present in the e-liquid.

Even though traced in small amounts, other virulent compounds were identified and proved to play a considerable role in triggering carcinogenesis in different organs. Among them are included Tobacco Specific Nitrosamines (TSNAs), carbonyl compounds, metals, volatile organic compounds and phenolic compounds.

In January 2018, laboratory experiments3, 6 emonstrated E-Cigarette Smoke (ECS) to be damaging to the DNA of lab rat’s cells in specific organs, namely the lungs, the bladder and the heart. The substances of the vapor seem to also inhibit DNA repair resulting in cancer and heart disease. Further researches were made and emphasized the credibility of this proposal. As a matter of fact, a metabolite of nicotine, called nicotine derived nitrosamine ketone was shown to reinforce mutational activity and tumorigenesis in cultured human bronchial epithelial and urothelial cells. The concerned constituents could therefore be responsible for lung and bladder cancer, as well as heart disease in humans. Furthermore, the penetration of these substances and some specific types of flvorings inside the lungs; particularly diacetyl (found in 75% of the flavorings) and benzaldehyde (contained in Cherry flavors) could induce modifications in the airways and be responsible for chronic bronchitis symptoms (cough and phlegm), oxidative stress and even asthma symptoms; although another paradoxical effect of e-cigs on asthma is subsequently discussed.

Not to mention that reflective reviews have identified cases of default in e-cigs use. Accidental swallowing of e-liquid for instance, had caused serious injuries, burns and poisonings which were in most cases fatal. This was explained by the fact that the characteristic features of the chemicals present in the e-liquid when ingested are different from those when inhaled.

The implication of e-cigs in smoking cessation

Nonetheless, one unquestionable fact is that vaping is way less harmful than smoking and the odds of developing cancer are higher in tobacco smoke expo- sure1. This is based on the fact that, comparing tobacco smoke inhalation to vaping, many adverse health effects induced by the former are absent while using the latter. Explaining thus why recent medical data propose e-cigs as potential aids in smoking cessation5. In one hand, clinical outcomes showed a progress in blood pressure and an improvement of respiratory signs of a numerous number of asthmatics after a period of switching to e-cigs1. The risk to develop dis- eases and the level of morbidity was esteemed to be decreased in this category of people.

In another hand, positive results were noticed for pregnant users going through smoking cessation. Despite the fact that any amount of nicotine should be withheld during pregnancy, clinical reports have shown the necessity of using e-cigs as a better alter- native for tobacco cigarettes. This concerned precisely highly addictive mothers who aspired to have healthier children.

Among the other NRT methods, e-cigs seem to be the most enticing regarding the shape and taste of these devices that are more or less similar to conventional cigarettes. Moreover, the users declare their approval and attraction to e-cigs thanks to the hand- to-mouth ritual of smoking that they can still keep. A noticeable reduction of craving tobacco smoke through a controllable habit was thus observed but only for people who intend to quit.

Todays’ concerns

However, the biggest concerns nowadays are in one hand, the major risk for teenagers and young adults to develop a new addiction that they never had before only after being attracted to these electronic devices and in another hand, the hidden and presumed side effects of e-cigs that health experts seem to dread the most.

Alarming effects were recorded in the case of non-smokers especially in teenagers and young adults who seem to develop new addictions for nicotine and other addictive substances such as cocaine. Previous smokers appear to fail at keeping their withdrawal by using only e-cigs for the first time, and the long yearn- ing for nicotine is once again triggered after vapor in- halation. In addition, many more available and health- ier methods were proven to be more compelling for smoking cessation.

Conclusion

As a conclusion, the overall studies and clinical evidence made about electronic cigarettes have created a considerable controversy in public health. Thanks to their contribution in avoiding the alarming diseases induced by tobacco, the concerned devices were referred to as relatively convenient alternatives to conventional cigarettes in the process of smoking cessation, aside from vehement recommendations to avoid the major harmful effects especially to teenagers and pregnant women. However, it is still a major doubt, since it is considered as a dangerous gateway to develop new addictions, and seem to reveal more serious side effects that could be deleterious for human health.

Nascent resolutions were suggested to find less risky methods to defeat the dreadful act of smoking, that aim for as much reduced nicotine as possible.

References

1 - Rigotti, Kalkhoran. E cigarettes. (2018). J.A Melin (Ed.), Up- ToDate. Waltham, MA: UpToDate Inc. http://www.uptodate.com

2- Dinakar, C. & O’Connor, G. T. The health effects of electronic cigarettes. N Engl J Med. 375, 1372–1381 (2016).

3- https://www.medicalnewstoday.com/articles/216550.php

4- Harrell MB, Weaver SR, Loukas A, et al. Flavored e-cigarette use: Characterizing youth, young adult, and adult users. Pre- ventive Medicine Reports. 2017;5:33-40.

5- Farsalinos K. Electronic cigarettes: an aid in smoking cessa- tion, or a new health hazard? Therapeutic Advances in Respi- ratory Disease. 2018;12:1753465817744960.

6- Lee H-W, et al. (2018) E-cigarette smoke damages DNA and reduces repair activity in mouse lung, heart, and bladder as well as in human lung and bladder cells. Proc Natl Acad Sci USA115:E1560–E1569.

7- Mishra A, Chaturvedi P, Datta S, Sinukumar S, Joshi P, Garg A. Harmful effects of nicotine. Indian Journal of Medical and Pae- diatric Oncology : Official Journal of Indian Society of Medical & Paediatric Oncology. 2015;36(1):24-31. doi:10.4103/0971- 5851.151771.

8- https://www.pulmonologyadvisor.com/asthma/asthma-ex- acerbations-from-e-cigarette-use/article/713567/ Image : https://upload.wikimedia.org/wikipedia/commons/0/00/ Vaping.jpg