E-cigarette users are possibly putting themselves at risk for developing heart disease, lung and bladder cancers, according to a new report. The findings, though preliminary, indicate that the devices—which aerosolize nicotine and contain no tobacco—may not be as safe as previously assumed.
The study, conducted by researchers from the New York University School of Medicine, exposed mice to e-cigarette smoke (ECS) for 12 weeks at a dose and duration equivalent to light e-cigarette smoking for 10 years in humans. By the end of the trial, the smoke had caused DNA damage in the animal’s lungs, bladders and hearts, as well as limiting lung proteins and important DNA repair.
Evidence points to the “almost unambiguous” conclusion that nicotine can convert to a carcinogen once inside the human body, said study author Moon-shong Tang, a professor of environmental medicine and pathology at NYU School of Medicine. “Nicotine is not as innocent as conventional wisdom thinks,” he said.
Currently, 18 million Americans smoke e-cigarettes. Sixteen percent of those users are high school students, according to the report. Manufacturers have advertised the devices as a safer alternative to traditional tobacco products.
A slew of studies examining the long-term health consequences of vaping have been conducted, but the conclusions have been mixed.
In 2013, a trial found the practice to be as effective in helping smokers quit as using nicotine patches. Another study, published August 2017, compared cancer potencies of e-cigarettes and tobacco smoke and found most ECS to have a cancer risk of less than 1 percent of that from smoking.
Many are worried that the mild flavor of ECS will hook young people on nicotine, encouraging teenagers to smoke tobacco in the future. In 2016, the U.S. Surgeon General Vivek Murthy called e-cigarette use among American youth a “major public health concern,” citing a 900 percent growth rate among high school students.
Tang wouldn’t recommend vaping to nonsmokers, in particular young people: “Don’t think a vapor is harmless.” As for cigarette smokers thinking about going electronic, Tang hesitates. “We don’t know which one is more harmful,” he said.
This latest study is not, by itself, conclusive. Tumors can’t develop in 12 weeks—the length of the study—and if tobacco smoke-induced cancer is indeed a model for e-cigarette smoking-induced cancer, then meaningful human evidence won’t be available for at least another decade.
In the meantime, scientists are turning to animal experiments, which may be able to provide further evidence as to the full-blown effects of e-cigarette smoking in about a year.