What Do We Know About Electronic Cigarettes for Smoking Cessation?

At its peak in 1965,  more than 40% of U.S. Americans smoked cigarettes. Today, that number is  closer to 12%. Unfortunately, despite this amazing public health triumph, that translates into more than 28 million people in the U.S. who still smoke (defined as smoking ≥100 cigarettes during a lifetime and now smoking cigarettes either every day or some days). Cigarette smoking remains the leading cause of preventable premature death in the U.S. and globally. It seems important, then, to continue to find effective ways to reduce the number of people who smoke tobacco.

A recent study adds to the mounting body of evidence that electronic nicotine delivery systems, i.e., electronic cigarettes or e-cigarettes, must be considered as one of the approaches to helping people stop smoking combustible cigarettes and other forms of tobacco. Despite the strength of the evidence, this is a controversial statement. Concerns about long-term adverse side effects and the risk of addicting teenagers to nicotine have dominated the conversation about e-cigarettes, often obscuring the scientific data on their effectiveness in helping people to stop smoking.

E-cigarettes deliver mostly only nicotine, which is not a carcinogen, and they do not deliver the host of toxic substances that are inhaled by people who smoke combustible tobacco products. Therefore, it is widely believed that e-cigarettes carry a much lower risk of causing cancer and other diseases than combustible cigarettes. The question has been whether e-cigarettes are effective as tools to promote smoking cessation. The two most recent high-quality studies confirm they are.

E-Cigarettes Better Than Standard Care

The study was published in the  New England Journal of Medicine last February and was conducted in Switzerland. 1,246 cigarette smokers were randomized to receive either e-cigarettes or standard care delivered by nurses. Participants in both groups were free to use nicotine replacement therapies like nicotine gum and could be prescribed approved medications for smoking cessation (varenicline or bupropion) at the discretion of their own care providers. Standard care involved cognitive behavioral therapy, motivational interviewing, and shared decision making. At the six-month assessment, a significantly greater number of participants in the e-cigarette group had continuous abstinence from tobacco smoking compared to those in the standard care group. Many of the people in the e-cigarette group continued to use them at the six-month assessment period. Serious adverse events did not differ between the groups. No industry funding was involved.

In an  accompanying editorial in the New England Journal of Medicine, Nancy A Rigotti of Harvard Medical School wrote: “The evidence now supports a strong conclusion that e-cigarettes are tools that clinicians can use to help adults stop smoking, especially those who are unable to quit with current evidence-based treatments…The burden of tobacco-related disease is too big for potential solutions such as e-cigarettes to be ignored.”

A Cochrane Report Agrees

A 2024 update of the  Cochrane meta-analysis of randomized clinical trials involving e-cigarettes reached similar conclusions as these two studies: e-cigarettes are effective interventions for helping people stop smoking and at least through six months seem to have only mild to moderate adverse side effects, like throat irritation and cough. Cochrane reports often frustrate clinicians and patients because they frequently do not reach firm conclusions regarding interventions under investigation, concluding instead that more studies are needed. Strikingly, in the case of e-cigarettes, the Cochrane report makes a firm conclusion about their effectiveness.

Why then, given what appears to be very strong evidence for the effectiveness of e-cigarettes in helping people give up a habit that is destined to make many of them very sick and even die, is it controversial to call for their inclusion in clinical guidelines for smoking cessation interventions? The reason is the very understandable fear that people will use e-cigarettes recreationally and not just for the purpose of smoking abstinence. This is especially worrisome when it comes to adolescent use of e-cigarettes because, as we have noted, very little long-term data are available about the safety of nicotine-delivery systems and nicotine is clearly an addictive substance. Although the number of adolescents who use e-cigarettes  appears to be dropping in recent years, almost 10 percent of U.S. youth reported using them in 2022.

There is a  misperception among many people that vaping—the term often applied to using e-cigarettes—is as or even more harmful than smoking combustible tobacco products. The risk-benefit ratio when it comes to using e-cigarettes for people who cannot successfully stop smoking by other methods seems clear: e-cigarettes are better than continuing to smoke. At the same time, there are legitimate concerns that easy availability of e-cigarettes, despite laws banning their sale to minors, leads to the adoption of an addictive behavior that could have long-term adverse consequences. As one e-cigarette advocate recently told us, “If you don’t smoke, don’t use these products.”

For people who cannot stop smoking via other methods, e-cigarettes are a viable medical intervention to help them. Policymakers will have to decide how to balance the science here with the need to keep e-cigarettes out of the hands of adolescents. We agree with Dr. Rigotti when she writes that “It is now time for the medical community to acknowledge this progress and add e-cigarettes to the smoking cessation toolkit.”