E-cigarettes also seriously harm health. One of the arguments of those who distrust this claim is that they cause less harm, but that does not mean they are harmless. Furthermore, scientists and doctors have always suspected the harm, but time and data accumulation were needed to turn hypotheses into proven facts.
Now, a team of researchers from Australia has conducted a review of various studies on e-cigarettes from 2017 to 2025. Their conclusions are clear: devices containing nicotine are likely carcinogenic to humans and will cause an as yet undetermined number of cases of mouth and lung cancer. In a press release, the authors, who publish the results in the journal Carcinogenesis, state that "the conclusion is unequivocal, although human studies estimating the risk will take decades to accumulate."
Rodrigo Córdoba, associate professor at the Faculty of Medicine of the University of Zaragoza and member of the Tobacco Group of the Spanish Society of Family and Community Medicine (semFYC), comments that the Australian work "provides very solid data to start talking about vaping and cancer." In this regard, Josep Maria Suelves, researcher at the Behavioural Design Lab at the UOC eHealth Center, board member of the Public Health Society of Catalonia and the Balearic Islands, also emphasizes the analysis and indicates that exposure to e-cigarette aerosols with nicotine is associated with some key characteristics of carcinogenesis, such as DNA damage, oxidative stress, and epigenetic changes, which contribute to increasing the risk of oral cavity cancer, lung cancer, and other forms of cancer among people using these devices, even if they have not been users of conventional tobacco products.
Impact on Spanish Society
In Spain, according to data from the EDADES 2024 survey, 19% of the population aged 15 to 64 has used e-cigarettes (with or without nicotine) at some point in their lives. The prevalence of use is higher in men across all age groups. Regarding age, the 15 to 24 age group has the highest consumption, and 54.6% of students aged 14 to 18 have used these devices.
Both, in statements to SMC and as members of the National Committee for Tobacco Prevention (CNPT), make it clear that, according to the available scientific evidence, "proposing the use of e-cigarettes as a safe and effective strategy to reduce the risks associated with tobacco use is not appropriate." They also insist on urging health authorities to "implement new measures to prevent the initiation of their use among young people and adolescents, better regulating their promotion and marketing, limiting the use of flavors and designs that make them more attractive, avoiding the marketing of disposable devices, and subjecting them to an appropriate tax regime due to their negative impact on public health," emphasizes Suelves, vice president of the CNPT.
In our country, Law 28/2005 on health measures against smoking is currently undergoing reform; it is currently in the process at European levels. The medical community and patient associations welcome it with hope after more than two decades without major modifications. This reform is included in the Comprehensive Plan for Tobacco Prevention and Control 2024-2027.
This legislative reform does restrict vapers, in addition to tobacco: it includes for the first time the prohibition of the sale of single-use e-cigarettes, and new products (vapers, nicotine pouches...) are equated with traditional ones. However, it does not regulate their sale specifically, something that traditional tobacco must comply with (only available in vending machines and tobacco shops).
It has often been said by authors linked to the industry that the toxic content is much lower, but Córdoba assures that they "omit that a regular consumer of these products can take more than 70,000 inhalations per year and that there is no safety threshold against Group A carcinogens such as heavy metals, nitrosamines, and others. Therefore, the conclusions are entirely plausible."
Córdoba estimates that the relationship of e-cigarettes with the carcinogenic effect was a possibility that would take time to demonstrate, "since an average consumption of 15 to 20 years is needed to prove it." Córdoba highlights the description of the key processes linked to cancer: "The breakdown of a chemical compound due to heat leading to the modification of flavorings and nicotine. The studies demonstrate genetic alterations, and animal studies (mice) have already observed a carcinogenic effect on the lungs and urinary bladder." The semFYC doctor also reveals that "there are already several studies linking e-cigarettes to oral cancer and presenting the first studies on lung cancer."
This nicotine combines with a range of toxic compounds that help leave a greater mark on the body. According to the Spanish Society of Pneumology and Thoracic Surgery (SEPAR), Juan Antonio Riesco points out that there are reports from various scientific societies and numerous research studies that "have determined that e-cigarette vapor contains a large number of toxic substances (acrolein, acetaldehyde, and formaldehyde are produced as a result of heating the glycerin in e-liquid; heavy metals like chromium, lead, nickel, carcinogenic substances like benzo[a]pyrene, some nitrosamines) that will be toxic to the body: mainly at the cardiovascular and respiratory levels."
Along with them, the presence of nicotine, as Riesco points out, also responsible for the Tobacco Unit at the University Hospital of Cáceres and spokesperson for the Tobacco Area, "demonstrates its high addictive capacity, leading consumers to require a significant daily amount of consumption associated with gestural, psychological, and social dependence (similar to behavioral tobacco)."
Córdoba emphasizes that "the industry does everything possible to discredit all scientists who publish this type of articles that jeopardize their formidable business, and that must be taken into account."