Even nicotine-free e-cigarettes damage blood vessels

A study published in Radiology August 20 suggests the harm of vaping tobacco products isn’t limited to nicotine itself, with users showing evidence of blood vessel damage even after smoking nicotine-free e-cigs.

The work, which focused on the short-term impacts of vaping in 31 healthy non-smokers, compared MRI results from before participants vaped a nicotine-free e-cigarette to those generated after a single episode of vaping. Principal investigator Felix W. Wehrli, PhD, a professor of radiologic science and biophysics at the University of Pennsylvania School of Medicine, and colleagues said it was clear upon analysis that vaping reduced users’ blood flow and impaired endothelial function in their femoral arteries.

“While e-cigarette liquid may be relatively harmless, the vaporization process can transform the molecules—primarily propylene glycol and glycerol—into toxic substances,” Wehrli said in a release. “Beyond the harmful effects of nicotine, we’ve shown that vaping has a sudden, immediate effect on the body’s vascular function and could potentially lead to long-term harmful consequences.”

For the study, participants took 16 three-second puffs from a tobacco-flavored e-cigarette containing propylene glycol and glycerol but no nicotine. Wehrli’s team tracked users’ vascular reactivity with a thigh cuff and used multiparametric MRI to image participants’ femoral arteries and veins before and after each vaping episode.

The researchers found that, on average, their subjects experienced a 34% reduction in femoral artery dilation, 17.5% reduction in peak blood flow, 20% reduction in venous oxygen and 25.8% reduction in blood acceleration after cuff release. The results were striking considering the fact that no participants were smokers at the study’s baseline.

Wehrli et al. said e-cigarettes are often advertised as a healthier alternative to smoking traditional cigarettes, but in reality we don’t know much about the short- or long-term consequences of vaping. In this study, it seemed the solvents, flavorings and additives in the vapor’s liquid base exposed users to respiratory tract and blood vessel damage.

“I would warn young people to not even get started using e-cigarettes,” Wehrli said. “The common belief is that the nicotine is what is toxic, but we have found that dangers exist independent of nicotine. Clearly if there is an effect after a single use of an e-cigarette, then you can imagine what kind of permanent damage could be caused after vaping regularly over years.”

Wehrli and colleagues’ results come at a time when at least 15 states have identified more than 120 cumulative cases of vaping-related lung disease or injury. The CDC said August 17 it’s investigating dozens of cases of severe pulmonary disease among people using e-cigarettes in the U.S.