E-Cigarettes and Health: What We Know and What We Still Need to Discover

The new scientific statement, “Cardiopulmonary Impact of Electronic Cigarettes and Vaping Products,” details the latest usage data and trends, identifies current health impacts, highlights existing basic and clinical scientific evidence surrounding e-cigarettes and recommends research priorities to further understand the short- and long-term health effects of e-cigarette use.

Vaping products, also known as e-cigarettes, are battery-operated systems that heat a liquid solution, or e-liquid, to create an aerosol that is inhaled into the lungs. Most e-liquid formulations deliver nicotine, which has been established as having negative health effects as well as strong addictive properties. The products may also contain other substances, most commonly tetrahydrocannabinol (THC), the psychoactive element of cannabis, as well as methamphetamine, methadone or vitamins. The liquids also include humectants (hygroscopic carriers such as propylene glycol and vegetable glycerol) that act as solvents and create a water aerosol or vapor, flavoring agents, cooling agents such as menthol and sweeteners, in addition to metals from the heating coil and other chemicals.

“E-cigarette companies have suggested that their products are a way to quit smoking traditional cigarettes. There is no strong evidence to support this beyond any short-term benefit. The lack of long-term scientific safety data on e-cigarette use, along with the potential for the addiction to e-cigarette products seen among youth, are among the reasons the American Heart Association does not recommend e-cigarette use for cessation efforts,” said Rose Marie Robertson, M.D., FAHA, the Association’s deputy chief science and medical officer and co-director of the Association’s Tobacco Center of Regulatory Science. “It’s also important to note that e-cigarette products are not approved by the U.S. Food and Drug Administration (FDA) for tobacco cessation. The Association recommends a combination of multiple-episode cessation counselling accompanied by personalized nicotine replacement therapy with FDA-approved doses and formulations, as well as medications to help control cravings, to help people who smoke cigarettes with cessation. And all of this needs to be undertaken with the understanding that quitting often takes many tries, and any failures should be seen as just episodes to learn from on the road to finally beating a powerful addiction for good.”

The scientific statement writing committee emphasizes a critical need for additional knowledge and research, specifically:

  • Future research should focus on gaining knowledge about serious and potentially long-term effects of e-cigarettes on the heart, blood vessels and lungs.
  • Studies are needed that include patients with pre-existing cardiopulmonary disease, such as coronary artery disease or chronic obstructive pulmonary disease, to evaluate and compare outcomes among e-cigarette users in comparison to traditional smokers, and those who use e-cigarettes along with traditional cigarettes (referred to as dual users) and nonsmokers.
  • More in-depth research is needed about the common chemical ingredients in e-cigarettes and the effects they independently have on pulmonary and cardiac health.
  • Clinical studies are needed to study the risks and potential benefits of e-cigarettes as alternatives to traditional combustible cigarettes.
  • Since the long-term health impact of e-cigarettes may take decades to emerge, more molecular and laboratory studies are needed in the interim to help determine the biological implications of e-cigarette use.

“Because e-cigarettes and other vaping systems have only been in the U.S. for about 15 years, we do not yet have enough information on their long-term health effects, so we must rely on shorter term studies, molecular experiments and research in animals to try to assess the true risk of using e-cigarettes,” Jason Rose added. “It is necessary for us to expand this type of research since the adoption of e-cigarettes has grown exponentially, especially in young people, many of whom may have never used combustible cigarettes.”

 The scientific statement was prepared by the volunteer writing group on behalf of the American Heart Association’s Council on Cardiopulmonary, Critical Care, Perioperative and Resuscitation; the Council on Epidemiology and Prevention; the Council on Cardiovascular Radiology and Intervention; the Council on Lifestyle and Cardiometabolic Health; the Council on Peripheral Vascular Disease; the Stroke Council; and the Council on Arteriosclerosis, Thrombosis and Vascular Biology. American Heart Association scientific statements promote greater awareness about cardiovascular diseases and help facilitate informed health care decisions. Scientific statements outline what is currently known about a topic and what areas need additional research. While scientific statements inform the development of guidelines, they do not make treatment recommendations.

Mark Foster

Mark Foster