Scientists conduct randomized trial to assess e-cigarette versus traditional cigarette use

Reviewed by Emily Henderson, B.Sc.Nov 19 2020

Scientists and medical professionals have long debated whether pod e-cigarettes are a safer alternative to traditional cigarettes. A new study provides some insight.

In a collaboration between The University of Kansas Cancer Center, California State University San Marcos and Brown University, scientists conducted a six-week-long randomized trial comparing e-cigarette use to traditional cigarette use in African American and Latinx smokers. E-cigarettes simulate tobacco smoke via battery-powered devices that work by heating a liquid into a vapor that the user inhales.

Nikki Nollen, PhD, co-program leader of KU Cancer Center's Cancer Prevention and Control research program, served as site principal investigator.

"Fourth generation e-cigarettes contain high concentrations of nicotine and other appealing features that may support switching and reduce potential health risks among those who smoke combustible cigarettes," Dr. Nollen said. "We wanted to examine the biomarkers of exposure in both groups and determine the risk-benefit tradeoff of e-cigarettes."

Those who switched to e-cigarettes experienced a significant reduction in a certain biomarker called NNAL. When NNK, a tobacco-specific lung carcinogen is metabolized, it converts to NNAL, indicating the body's exposure to tobacco products. E-cigarette users also experienced a dramatic drop in carbon monoxide and self-reported respiratory symptoms. Nicotine exposure, lung function and blood pressure remained unchanged.

"What was most surprising was the magnitude of change experienced by those in the e-cigarette group," Dr. Nollen said. "They reduced their NNAL by 64%, carbon monoxide by 47% and respiratory symptoms by 37% compared to those in the control group who continued to smoke cigarettes as usual."

Dr. Nollen and the team were also surprised to witness that a complete switch to e-cigarettes was not needed to achieve benefits. Those in the e-cigarette group who only partially switched – i.e., became dual users of both cigarettes and e-cigarettes – also experienced reductions in NNAL, carbon monoxide and respiratory symptoms, though to a lesser degree than those who made a complete switch.

The findings of the clinical study – the first such trial to examine fourth-generation salt-based nicotine e-cigarettes – were published in JAMA Network Open.

Improving disparities

To recruit participants for the study, Dr. Nollen and her team leaned on a 20-year partnership with Swope Health Services Central, a federally qualified health center located in Kansas City, Missouri. More than 85% of Swope's patient population is African American. KU Cancer Center members have teamed up with Swope on 10 studies over the last two decades.

Overall, African Americans and Latinxs tend to smoke less compared to other ethnicities, but they are more likely to develop and die from tobacco-related health issues.

The two minorities have largely been underrepresented in e-cigarette studies. Excluding these groups from such studies only worsens the uneven burden of tobacco-related deaths and disease they experience.

According to Dr. Nollen, longer studies must be conducted in order to understand the long-term effects of e-cigarettes, but this study may serve as a springboard for additional research endeavors.

Quitting cigarettes is the priority. But for those unwilling or unable, our findings support using e-cigarettes as a harm reduction strategy for African American and Latinx smokers who experience significant tobacco-related health disparities."

Nikki Nollen, PhD, Site Principal Investigator and Co-Program Leader, Cancer Prevention and Control Research Program, University of Kansas Cancer Center