Report: What’s Known About the Harms and Benefits of E-Cigarettes

closeo up of e-cigarette in man's hand with smoke all around

The National Academies of Sciences, Engineering, and Medicine (NAS) has released a new report looking at more than 800 scientific studies about the effects of electronic cigarettes (e-cigarettes) on users’ health. The study, mandated by Congress, is the most comprehensive analysis of existing research about e-cigarettes.

The report draws dozens of conclusions about a range of public health impacts of e-cigarettes. However, it does not conclude whether the overall impact is either positive or negative. The report pays special attention to the impact of e-cigarettes on children and teenagers, who use them at higher rates than adults do.

 Conclusions from the report:

  • Exposure to nicotine varies, depending on the device, the e-liquid used in the device, and how the user operates it. Experienced adult users of e-cigarettes can get just as much nicotine as from regular cigarettes. Nicotine is the addictive drug in tobacco.
  • Most e-cigarettes contain and emit a variety of substances in addition to nicotine that could be toxic. There is generally far less exposure to these other toxic substances from e-cigarettes than from regular cigarettes.
  • Using e-cigarettes can be addictive. There is some evidence that the severity of an addiction to e-cigarettes likely depends on many factors, including the type and brand of the device, and the nicotine concentration and flavoring in the e-liquid used. There is some evidence that the severity of an addiction to e-cigarettes is lower than for regular cigarettes.
  • Completely switching to e-cigarettes reduces the exposure to many toxins and cancer-causing substances in regular cigarettes. However, many adults who use e-cigarettes also continue to use other tobacco products, too. In the short term, completely switching to e-cigarettes can lower the harmful effects to the body caused by smoking. Long-term effects are not yet clear because e-cigarettes are relatively new. They have only been on the market since 2006.

E-cigarettes’ impact on youth

Young people use e-cigarettes more than any other tobacco product, and use them at higher rates than do adults. The NAS report found a strong association between youth using e-cigarettes and their likelihood of trying conventional cigarettes. It’s not yet clear whether young e-cigarette users who try regular cigarettes will continue smoking over the long term.

In the past, the US Surgeon General has criticized e-cigarette marketers for using strategies that target young people. Nicotine is highly addictive at any age, but is especially dangerous for children, teenagers, and young adults because their brains are still developing at this age.

Most users, including youth, prefer to use flavored e-cigarettes. Many flavors appear to be aimed at children, with names such as Cherry Crush and Cotton Candy.

American Cancer Society experts weigh in

Experts from the American Cancer Society (ACS) acknowledge the continuing issues brought up by the NAS report, including:

  • An association between the use of e-cigarettes by youth and the eventual use of regular cigarettes
  • Evidence that e-cigarettes are not harmless, but are likely to be much less harmful than regular cigarettes
  • The long-term risks of continued use of e-cigarettes are not yet known

These are similar to findings of a recent comprehensive review conducted by ACS researchers. That review concludes that the overall population health effects of electronic cigarettes are complex, and there is not yet agreement among the scientific community. The populations most vulnerable to harmful effects of e-cigarettes might be youth and pregnant women because they are more likely than other populations to be harmed by exposure to nicotine.

The American Cancer Society Cancer Action Network, the advocacy affiliate of the American Cancer Society, is urging the US Food and Drug Administration (FDA) to use its full authority to regulate all tobacco products, including e-cigarettes. The FDA announced in 2016 that it would begin regulating e-cigarettes, hookahs, cigars, and other tobacco products the same way it does regular cigarettes. But it later delayed until 2022 the deadline for tobacco companies to apply for approval to keep selling their products.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

  • Public Health Consequences of E-Cigarettes. Published January 23, 2018 by the National Academies of Sciences, Engineering, and Medicine. Washington, D.C.
  • Key issues surrounding the health impacts of electronic nicotine delivery systems (ENDS) and other sources of nicotine. Published September 29, 2017 in CA: A Cancer Journal for Clinicians. First author Jeffrey Drope, PhD, American Cancer Society, Atlanta, Ga.


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