Some cigarette users take up vaping to help them quit smoking, or with the intention of switching to e-cigarettes altogether.
But real-world research suggests that many adults who smoke cigarettes and vape — what’s known as dual use — continue smoking over the long term, sometimes alongside e-cigarettes.
“This study suggests that at the population level, vaping may not help people kick the smoking habit,” study author Nandita Krishnan, PhD, a postdoctoral scholar at Stanford University in Palo Alto, Calif., said in a press release.
“People who concurrently use e-cigarettes and cigarettes experience increased health risks, and both products deliver nicotine, which is addictive,” she added. “We should be trying to help them quit both smoking and vaping.”
Krishnan was a researcher in the Department of Prevention and Community Health at the George Washington University Milken Institute School of Public Health in Washington, D.C., at the time the study was conducted.
The study was published Dec. 13 in the journal Tobacco Control.
Researchers follow dual users
In the study, researchers examined data for 2013 to 2019 from the U.S. Population Assessment of Tobacco and Health (PATH) Study, a national longitudinal study of tobacco use.
The same people fill out this survey every year, so researchers are able to look at how dual users’ tobacco use changes over time: Do they quit smoking cigarettes? Do they give up e-cigarettes? Do they quit both or continue using both?
Researchers identified 545 adults from the first year who reported being a current e-cigarette user and cigarette user — meaning they vape and smoke every day or on some days. By the last year, researchers had complete data on 541 of these people.
For the study, e-cigarettes included other electronic nicotine products such as e-cigars, e-pipes and e-hookahs.
During the first year, just over half of the dual users were between 25 and 44 years old; just over half were men; and around three-quarters were non-Hispanic white.
In addition, around 3 out of 4 individuals smoked cigarettes daily, about 1 in 3 vaped daily, almost 2 out of 3 drank alcohol. About 1 in 4 smoked cannabis.
The majority of people thought vaping was less harmful than smoking, which is supported by some research — at least over the short- and medium-term.
However, Thomas Ylioja, PhD, a cessation expert and clinical director of health initiatives at National Jewish Health in Denver, said we don’t have a lot of information on the health impacts of long-term e-cigarette use, because these products have been around a relatively short time.
“It took about 20 to 30 years to really have a full understanding that cigarettes could cause cancer,” he said. “And it’s taken us about 70 years to really understand the magnitude of harm from smoking cigarettes.”
Ylioja was not involved in the new research.
Many quit vaping, but keep smoking
Over the six years of the study, the proportion of people who vaped dropped to 41%, while the proportion of smokers fell to 68%.
Researchers grouped people by their smoking and vaping behaviors. About two-thirds of vapers stopped vaping early on — by about half-way through — while the rest continued vaping.
In contrast, just over half of smokers continued smoking, while just over one-quarter steadily quit using cigarettes across all years.
Under 20% quit smoking early on or by halfway through the study.
Researchers also looked at the combined patterns of vaping and smoking. The most common pattern —occurring in four in ten people — was stopping vaping early, but continuing to smoke.
“That’s concerning, because if electronic cigarettes are less harmful than combustible cigarettes — at least in the short term — then most people were continuing to use the more harmful products and not the less harmful products,” said Ylioja.
This fits with other research showing that adults tend to stick with combustible cigarettes more than with e-cigarettes.
The results of the new study also show that just one in ten people quit both vaping and smoking early on, while around one in seven people continued to use both tobacco products.
Those early quitters of both products were more likely to smoke cigarettes less than daily, researchers found. They write that this suggests “that smoking reduction could help dual users to quit using both products.”
Ylioja said this isn’t surprising, because non-daily use suggests that a person had a lower level of nicotine dependence.
Aligns with earlier research
What the researchers found in this study “tracks with what we see in other studies — that those who smoke less or are non-daily smokers are more likely to quit,” he said.
Because this is an observational study, researchers can’t show that e-cigarette use impacted cigarette use, or vice versa.
Researchers also had to rely on participants’ self-reports of smoking and vaping habits, and they didn’t have information on which e-cigarettes people used.
Ylioja said as a result, the results should be viewed with some caution, because e-cigarettes that people were using early during the study period were not efficient at delivering nicotine.
“One of the reasons people stopped using e-cigarettes in some of these earlier studies is because they weren’t getting enough nicotine from the device,” he said. “They would describe them as being less satisfying than smoking a cigarette.”
Newer e-cigarettes have gotten better at delivering nicotine, so PATH data from more recent years may show different vape trends for dual users. Future studies will need to examine these data.
Quit lines and cessation medications help
While some research suggests that e-cigarettes may help people quit smoking, other studies have found the opposite.
Ylioja said the new study doesn’t provide support for the use of e-cigarettes as a tool to quit smoking either.
“What I see here is that people who are dual users are much more likely to continue smoking,” he said, “so we should definitely encourage people to quit both products.”
He said there are tools to help people quit, including quit lines — which are free to use — as well as cessation medications such as nicotine replacement therapy, bupropion and varenicline.
