Often suggested as a method to help quit smoking, vaping is popular among US adults, with an estimated 14.9% having used e-cigarettes. There have even been competitive vape events, where competitors face off to puff the most impressive vape clouds. However, e-cigarettes have been blamed for rising nicotine use in teens. E-cigarettes are certainly popular with young people, with 37.3% of 12th graders reporting vaping in the past year.
However, the variety of vape flavors that have been accused of enticing young people could have even more dangerous effects. A preclinical study by USF health shows that e-liquid flavorings could damage the heart, suggesting that the candy-flavored clouds may not be as sweet as they seem.
The study focused on three e-liquid flavors: vanilla custard, Hawaiian POG, and apple jax, all of which contain nicotine. When exposed to these vapors, mouse cardiac muscle cells showed decreased cell viability. Compared to cells only exposed to air, cells exposed to flavored vapor had more necrotic cells and increased apoptosis (cell death). These negative effects were shown to worsen with increased dose and exposure time.
The vanilla custard and apple jax flavors were more toxic to cells than Hawaiian POG, with vanilla custard being the most toxic of the three. This could be due to vanilla custard and apple jax containing aldehydes used for vanilla and cinnamon flavoring, which have been shown to be toxic to cells in previous studies. Hawaiian POG did not contain these compounds.
Exposure to vapor also had a negative effect on human stem cell-derived heart cells, which beat regularly. Exposure to just the e-liquid base showed no significant effects on the cells. Cells exposed to e-liquid base with added nicotine had significantly reduced beating rates, and exposure to e-liquid base with vanilla custard flavoring reduced the beating rate even more. Lead researcher on the study Dr Sami Noujaim explained in a press release, "this experiment told us that the flavoring chemicals added to vaping devices can increase harm beyond what the nicotine alone can do."
The effect of vaping on the hearts of mice was tested, with mice puffing either air or vanilla custard vapor over the course of 10 weeks. By five weeks, the activity in the hearts of the mice breathing in vanilla custard were affected. The effects experienced by the mice were indicative of poor cardiovascular outcomes and decreased parasympathetic activity in the heart. The mice were also more prone to ventricular tachycardia, a type of abnormal heartbeat.
Despite being touted as a safer alternative to smoking, this study indicates that vaping could come with its own dangers. Further research needs to be done on the impacts that chemicals found in e-liquids could have on the body, especially given their popularity with adults and young people alike.