Clearing the Air on E-Cigarettes

It would be an understatement to say e-cigarettes are controversial. Few products have sparked such discord and made as many headlines, and scientists are working in earnest to separate fact from fiction. A sharp uptick in reported vaping-related illnesses and deaths, as well as use among teens, underscore the need for thorough research.

E-cigarettes are battery-operated devices that heat a liquid comprised of nicotine, flavoring and additives. A primary difference between how e-cigarettes and conventional cigarettes work is the liquid is heated and not burned like tobacco leaves in cigarettes. The act of puffing, or “vaping,” heats the liquid, producing an aerosol that is inhaled. According to Matthias Salathe, MD, chair of the University of Kansas Medical Center’s Department of Internal Medicine and member of The University of Kansas Cancer Center, many products contain as much as 20 cigarettes worth of nicotine, a highly addictive stimulant drug.

A pulmonologist, Salathe’s work on the health effects of vaping has received national attention. In 2019, he and his team published a study in the American Journal of Respiratory and Clinical Care Medicine that showed vaping nicotine damages the natural ability of our lungs to clear mucus. Using a robot containing human airway epithelial cells as well as a sheep model — chosen because their airways work like a human’s —the team observed the effects of vaping.

“In both models we found the airway becomes inflamed when you vape, and the ability to clear mucus out of the lung is detrimentally affected. These are both similar side effects of tobacco smoke,” Salathe said.

Humans inhale about 5,000 gallons of air every day — air that can be loaded with dust, pollen and viruses. Our lungs have evolved to expel these foreign particles, but if the lungs’ ability to clear stops working, it becomes harder to move phlegm. Over time, it can lead to chronic bronchitis and may even develop into chronic obstructive pulmonary disease (COPD), the third leading cause of death in the United States.

Studies led by other institutions have demonstrated chronic vaping increases airway protease activity, a substance that breaks down other proteins, equal to that of smoking. In addition, proteomic analysis showed that unique changes, different from smoking, occur with vaping.

Salathe said these mounting discoveries point to disturbing health risks.

“After you vape, your airways repair themselves. We believe constant turnover of the cells has a limit, meaning it can be repaired only so many times. The airways finally exhaust their ability to repair. That’s when real disease starts to set in,” Salathe said.

Real disease, including cancer, per a mouse study. Studies link chronic inflammation to DNA damage, a chief culprit in cancer development. Salathe adds that more research looking at long-term effects of subjects who do not want to quit vaping is also needed.

The cancer center’s Cancer Prevention and Control (CPC) research program has long focused its efforts on smoking cessation using FDA-approved products and evidence-based behavioral interventions — proven tools that have helped millions of smokers quit. Vaping has been marketed as an aid to quit traditional cigarettes, but the U.S. Preventive Services Task Force has stated there is insufficient evidence to recommend the use of e-cigarettes as a smoking cessation tool. According to Edward Ellerbeck, MD, MPH, chair of the department of Population Health and co-leader of the CPC research program, cancer center researchers are scrutinizing e-cigarettes’ potential role as an effective and safe way to quit tobacco.

“Smoking is still the number one cause of cancer in the United States, and lung cancer causes the highest number of cancer deaths every year in Kansas. We must do everything we can to address smoking and reduce cancer risk,” Ellerbeck said. “We need to figure out if e-cigarettes can play a role in the process. At the same time, our concern is that e-cigarettes are causing more harm than good.”

Ellerbeck worries the trendy vape pens are creating a new generation of nicotine addicts. The 2018 National Youth Tobacco Survey found e-cigarette use among high school students skyrocketed 78% from 2017 to 2018. Use increased 48% among middle school students in the same time period. This increase could be attributable to high nicotine content, fun flavors like mango and the ability to be easily concealed.

“In addition to reducing tobacco use in our community, we are also trying to reduce potential forces that may weaken tobacco control efforts at a population level,” Ellerbeck said. “We have made substantial progress over the last 50 years reducing tobacco use. Now we are at risk of taking major steps back.”

Beyond studying e-cigarettes at the bench and in the clinic, researchers are also looking at the public health implications. Ellerbeck is a member of a new Kansas state task force on vaping in schools, established at the direction of the state’s Board of Education. The vaping task force is looking at prevention of use as well as treatment for students already addicted to e-cigarettes. Currently approved tobacco cessation drugs can only be taken by those over 18. Behavioral programs targeted at teens include Resist, a program supported by the Kansas Department of Health and Environment and Tobacco Free Kansas Coalition, American Lung Association’s program, Not on Tobacco (N-O-T) and Truth Initiative’s e-cigarette quit program.

Numerous additional cancer center efforts include researching the flavor additives, advocating to raise the purchase age to 21 and studying the neurological effects of e-cigarette advertising on adolescents. The aim, Salathe emphasized, is to increase our understanding of the risks of vaping so people can make informed decisions.

“There are true dangers in the use of regular vaping products,” Salathe said. “We are not just dealing with acute health issues related to vaping. If we don’t advocate for more research to establish what can or cannot happen as a result of vaping, we must be prepared to see its long-term effects.”