OCT 19, 2019

Not worth the risk: e-cigs and lung inflammation

WRITTEN BY: Kathryn DeMuth Sullivan

E-cigarette use is on the rise and according to new research published in the journal Cancer Prevention Research, even short-term usage of e-cigs can be a cause for alarm due to resulting cellular inflammation. According to researchers of the study, which comes from The Ohio State University Comprehensive Cancer Center (OSUCCC), we are seeing a growing number of young never-smokers using e-cigs, as well as use by smokers who are trying to quit.

Senior author Peter Shields, MD, who is deputy director of the OSUCCC, comments that there is much public confusion regarding the medical concerns of e-cig usage, and that’s in part because although the FDA was granted regulatory authority over e-cig product design in August of 2016, science can’t keep up with the quickly evolving industry.

"The implication of this study is that longer-term use, increased daily use and the addition of flavors and nicotine may promote additional inflammation," says Shields. "The general perception among the public is that e-cigs are 'safer' than cigarettes. The reality is the industry is changing so fast ¬- and with minimal regulation -- that usage is outpacing the rate of our scientific understanding. It's becoming a public health crisis we should all take very seriously from a general pulmonary health, cancer risk and addiction perspective. E-cigs may be safer than smoking, but that is not the same as safe, and we need to know how unsafe they are."

Propylene glycol and vegetable glycerine, for example, are components of e-cigs that have been approved by the FDA for foods and cosmetics, but their effects are unknown when they are heated and inhaled. To better understand those effects, the researchers behind the study conducted a trial with 30 healthy, non-smoking volunteers, measuring the inflammatory impact that these two compounds had on the lungs via a procedure called bronchoscopy.

Of the 30 participants, half partook in a four-week intervention with e-cigs containing only 50% propylene glycol, while the others did the same with e-cigs with 50% vegetable glycerine. Neither group of e-cigs contained nicotine or flavors. There was also a control group of never-smokers. The researchers report that although the e-cig users showed only a small magnitude of increased inflammation when compared to the control group, this proves that even short-term usage can produce cellular inflammation. It is important to note that such inflammation is one of the main causes of lung cancer and other respiratory diseases.

The researchers hope to continue their investigations, with the intention of providing guidelines to create scientific evidence-based regulatory policies. "Human clinical trials can provide valuable information regarding actual toxicant exposure and risk for disease. Through the randomized clinical trial of healthy never-smokers over a month, we found that an increase in urinary propylene glycol, a marker of inhalation-e-cig intake, was significantly correlated with increased inflammatory response in the lung," says Min-Ae Song, first author of the manuscript and environmental health researcher at the Ohio State College of Public Health. "Future studies could be of longer duration, include an assessment of flavors, the effect by varying ratios of propylene glycol and vegetable glycerine, and examine randomization of smokers to e-cigs."

Sources: Cancer Prevention Research, Science Daily