While projections vary, it's estimated that somewhere around half of the more than 10 million adults who vape in the U.S. also smoke. And there are a number of reasons people give for both smoking and using electronic cigarettes, which turn nicotine into a vapor that can be inhaled.
Among them, some supplement smoking with vaping to skirt smoking laws and restrictions -- vaping where they can't smoke. Or they use e-cigarettes where it's not socially acceptable to smoke, such as in public places, at home and in cars. That's according to limited data on the reasons for what's called dual use, including a small study surveying people who both smoke and vape in the journal Tobacco Control, published online last year. "You can use e-cigarettes in some smoke-free areas where you cannot smoke, so that's a big motivation for a lot of smokers," notes study co-author Lucy Popova, an assistant professor of health policy and behavioral sciences at the Georgia State University School of Public Health.
Experts note that vaping is sometimes done in close quarters not only with others who use e-cigarettes, but also in proximity to people who don't vape or smoke. Some data indicates that adults are more likely to vape than smoke in homes and cars, even when children are present, despite the potential risk of of what's referred to as secondhand vaping for anyone exposed to the aerosol.
In addition, some report that they vape in place of smoking -- at least some of the time -- in an effort to save money by buying fewer cigarettes.
The most common reason cited by smokers for what's called dual use -- using both electronic nicotine delivery systems (as they're more broadly categorized) and smoked tobacco -- is the initial hope it will help them quit smoking. However, research shows the vast majority are unable to kick the habit. So some rationalize that vaping will help them at least cut back on the cigarettes they do smoke, although this doesn't necessarily happen either, according to data on dual use.
Another reason smokers may continue to use both is because they're not having the same sensory experience with e-cigarettes. For example, it's reported that smoking has a stronger effect that may help calm nerves, at least momentarily; by comparison, some surveyed for the Tobacco Control study felt vaping fell short in regards to helping them regulate emotions like stress and anxiety.
This dual use is especially concerning as the Centers for Disease Control and Prevention continues to investigate what it describes at an "outbreak of lung injury cases" associated with vaping involving more than 1,000 people across the U.S., and 18 deaths as of Oct. 1. And CDC Director Dr. Robert R. Redfield said in a statement that this may just be "the tip of the iceberg."
Though the cause of the outbreak and deaths still isn't clear, most involved using vaping products with THC -- the active ingredient in marijuana. More than a third of those affected are under 21 years of age and 80% are under 35, according to the CDC. "The problems with severe respiratory illnesses ... are disproportionately affecting young people," says Joanna Cohen, director of the Institute for Global Tobacco Control at Johns Hopkins Bloomberg School of Public Health.
Attracted by slick e-cigarette advertising and products with flavors that are especially attractive to younger users -- like cherry, cotton candy and piña colada -- teens are becoming an increasingly larger portion of e-cigarette users. About 1 in 4 teens now report having vaped. That, in turn, increases the likelihood of smoking, with some adolescents using both e-cigarettes and cigarettes.
Meanwhile, many adult smokers prefer e-cigarettes over quit aids -- such as the medication Chantix and the nicotine patch -- that are approved by the Food and Drug Administration for smoking cessation. But the data is still mixed on whether vaping could help a person stop smoking; the FDA hasn't approved e-cigarettes as a quit aid.
A study published in February in the New England Journal of Medicine found e-cigarettes were more effective than approved quit aids when each was accompanied by behavioral support that involved face-to-face consultation from a clinician. But other research suggests that having that extra source of nicotine can actually strengthen the addiction for those who smoke and vape, making it harder to quit smoking and contributing to relapse.
Another study published last year in Tobacco Control finds that e-cigarette use is highly variable. Among those vaping and smoking in 2013-2014, nearly 9 in 10 were still smoking tobacco cigarettes a year later. In total, only 12% had quit smoking, including 5% who were still vaping, and just 7% had stopped smoking and vaping -- and 44% were still doing both.
Most experts still suggest at least trying FDA-approved quit aids first -- and point out that while approved quit aids have their risks too, there's still much that's unknown about e-cigarettes. What's more, very little is understood about the potential health risks associated with smoking and vaping together.
Many people who smoke and vape -- i.e. are dual users -- do so indefinitely. They may rationalize that because they're vaping sometimes instead of smoking, they're reducing their risk, but the data doesn't seem to support this belief. People who smoke and vape "believe themselves to be somehow mitigating at least part of the risk, and we don't see any indication that's the case," says Dr. Thomas Houston, a family physician and former chair of the American Academy of Family Physicians Commission on Health of the Public and Science and of its now-dissolved Smoking Cessation Advisory Committee.
The Dangers of Dual Use
Dual use could lead to a greater dependence on nicotine, so for many, the rationale that by vaping they'll be able to smoke fewer cigarettes may be more of a pipe dream.
One 2018 study in the open access journal PLOS One that evaluated the impact of e-cigarette and cigarette use on heart health found that dual users smoked slightly more cigarettes -- or 10 per day, compared to nine daily, on average, for those who only smoked. "We were surprised to find that dual users smoked as many if not more conventional cigarettes compared to conventional cigarette-only users," says the study's senior author Dr. Gregory Marcus, a professor of medicine at the University of California, San Francisco, and an associate chief of cardiology for research at UCSF Health.
The researchers couldn't exclude the possibility that dual users, in the absence of having e-cigarettes, would've smoked even more. However, the finding "certainly suggested that e-cigarette use may simply be an add-on to other tobacco products rather than a substitute for conventional cigarettes," Marcus says, "and therefore should not be considered as a healthier alternative to conventional cigarettes -- or necessarily as a useful way to help avoid conventional cigarette use."
What's more, there was also some indication that, taken together, smoking and vaping could be even worse for a person's health. Doing both, for example, could further increase one's risk for problems involving an irregular heartbeat -- or arrhythmia. These can be dangerous and even fatal. The researchers note that the study provides at least initial evidence suggesting "that dual users are at higher risk of breathing difficulty and arrhythmias, and that this increased risk is likely attributable to e-cigarette use or the potential combined effect of cigarette and e-cigarette use."
They also reiterated the harms of e-cigarette use alone: As compared with those who don't smoke or vape, those who only vape "were more likely to report chest pain, palpitations, coronary artery disease and an arrhythmia." That's in line with previous research that also finds e-cigarettes increase cardiovascular risk.
Instead of mitigating the damage done by cigarettes, vaping and smoking together may have a greater negative impact. "We found that those dual users tended to feel worse, have a lower quality of life and generally have worse health," Marcus says.
Kicking Both Habits
Given these risks, clinicians roundly recommend ultimately working toward the healthiest goal of all: quitting both smoking and vaping.
"We all are sympathetic to the fact that it's not easy because this is a physical addiction, and (it) frequently has a psychological component," Marcus says. "But if this was my family member, and I wanted them to live not only a long life but also a vibrant life, where quality of life was of utmost importance, I would do everything I could to convince them to avoid all tobacco smoke as well as e-cigarettes."
If that's you -- or a loved one -- start with seeing a primary care doctor who is equipped to suggest options for smoking cessation. "I think our first choice is always the FDA-approved medications plus counseling," Houston says. All states also have quitlines staffed by counselors who can help you kick the habit. You can call 800-QUIT-NOW (800-784-8669) to connect directly to your state's quitline.
And if you fail -- as most do -- in your first (not to mention a second or third) quit attempt, keep at it. "The biggest predictor of successful quitting is just how many times you try to quit," Popova emphasizes. "So try and try again, and you'll get there."