A study in the Journal of the American College of Cardiology has added to mounting evidence that the flavored "e-liquids" used in vapes can hinder human cells' ability to sustain and function with the introduction of toxins into the body. The authors say these changes are notorious for causing heart disease.
"The public has this notion that e-cigarettes are safe," said study author Dr. Joseph Wu, director of the Stanford Cardiovascular Institute and a professor in the medical school's departments of medicine and radiology.
Experts say this idea comes not just from the presence of fewer cancer-causing chemicals than traditional cigarettes, but also from the fact that many vaping products are sold in sweetened flavors that may seem risk-free.
"As a result of this perception, a lot of kids pick up e-cigarette smoking," Wu said. "There are so many kids who are smoking e-cigarettes. And these kids are going to become adults. And these adults can become elderly patients that I, as a cardiologist will take care of later on."
The US Food and Drug Administration stated in November that vaping had increased almost 80 percent among high schoolers and 50 percent among middle schoolers from the prior year. Experts also worry that the devices could put adolescents' still developing brains at risk, get them addicted to nicotine early in life and be a gateway to smoking as well as other drugs.
In the study, which included six e-liquids with varying nicotine concentrations, Wu's team uncovered indications of the toxic effects -- including declining cell survival and symbols of increased irritation-- on a type of cardiovascular cell. As a proxy for what might happen in someone's blood vessels, the researchers observed how these cells responded when in contact with e-liquids as well as fluid from the blood of a small group of participants who had vaped. These effects varied between the liquids, with the most potent being a cinnamon-flavored product.
Other studies have observed the impact of vaping products at the cellular level and on cardiovascular health more broadly. A study last year showed that daily e-cigarette users had an increased risk of having a heart attack, though not as high as daily smokers.
"We're seeing more and more evidence that e-cigarettes do have a relationship with an increased chance of having a heart attack," says Dr. Lawrence Phillips, an assistant professor of medicine and director of outpatient cardiology at NYU Langone Health.
"When we compare traditional cigarettes to e-cigarettes, we're really not comparing apples to apples," said Phillips, who was not involved in the new research. "What we're finding is that both are having increased risk."