Smoking e-cigarettes can lead to toxic damage to human airway cells, suppress the immune system and alter inflammation, all the while boosting superbug virulence, according to a new study from researchers at the University of California, San Diego.
"This study shows that e-cigarette vapor is not benign -- at high doses it can directly kill lung cells, which is frightening," Laura Alexander, senior author of the study, said in a press release. "We already knew that inhaling heated chemicals, including the e-liquid ingredients nicotine and propylene glycol, couldn't possibly be good for you. This work confirms that inhalation of e-cigarette vapor daily leads to changes in the inflammatory milieu inside the airways."
The study consisted of both lab and mouse experiments. During the mouse experiments, signs of full-body inflammation increased by 10 percent in the airways and blood of mice that inhaled e-cigarette vapors for one hour a day, five days a week for four weeks compared to mice who did not inhale the vapors.
"We don't know specifically which lung and systemic diseases will be caused by the inflammatory changes induced by e-cigarette vapor inhalation, but based on clinical reports of acute toxicities and what we have found in the lab, we believe that they will cause disease in the end," Alexander said. "Some of the changes we have found in mice are also found in the airways and blood of conventional cigarette smokers, while others are found in humans with cancer or inflammatory lung diseases."
The study also found that e-cigarette vapor simultaneously benefits bacterial pathogens such as superbugs, as evidenced in the fact that Staphylococcus aureus bacteria showed an increased ability to form biofilms, invade cell pathways and resist antimicrobial peptides following e-cigarette vapor exposure. These findings were mirrored in a mouse model of pneumonia, where mice pre-exposed to e-cigarette vapor showed higher death rates than unexposed mice.
The findings were published in the Jan. 25 issue of the Journal of Molecular Medicine.
