COLUMBUS, Ohio – A new scientific statement issued by the American Heart Association calls on policymakers at the local, state and national levels to take action to reduce or prevent e-cigarette use among adolescents to lower lifetime cardiovascular risk. Current scientific evidence indicates e-cigarettes may adversely affect the cardiovascular and respiratory systems over the lifetime of users, according to the statement chaired by Loren Wold, professor and associate dean for research operations and compliance in The Ohio State University College of Medicine.
Since their introduction to the U.S. market in the early 2000s, e-cigarettes have become popular, particularly among adolescents, reversing years of lower rates of tobacco use in youth and young adults and declining nicotine dependency among users of combustible cigarettes. Adolescents who begin vaping now may become life-long tobacco or nicotine users, according to the statement published online today in the journal Circulation Research.
“Most studies on the use of e-cigarettes have been conducted in adults or in animals. It’s critical that we also understand how organ systems are affected in younger people who use e-cigarettes and, specifically, how these effects may persist into adulthood,” said Wold, whose recent research in mice has shown vaping has a significant and long-term cardiovascular effect on adolescent males into adulthood.
According to the statement, the toxicity of e-cigarettes remains poorly understood, partly because most manufacturers have not publicly disclosed the full list of ingredients. Since the exact composition of the products within the devices is not known, it is difficult to predict or determine the health effects on the lungs and heart. Other than nicotine or THC, e-liquids contain vegetable glycerin and propylene glycol, which are on the U.S. Food and Drug Administration’s “generally regarded as safe” list. However, these compounds were not intended to be inhaled and have not been tested to determine how inhaling them affects users. When heated, these compounds often break down into other chemicals such as formaldehyde, which is a known carcinogen.
“Inhaling any foreign substance can have effects on the respiratory and cardiovascular systems,” said Wold, who is also assistant dean for biological health research in the College of Nursing. “Furthermore, a person’s lung development continues into the early 20s, so adolescents who vape are at risk for stunting or altering their lung development and may not reach full lung function.”
Previous studies have found that people who use e-cigarettes have an increased risk for respiratory health issues, including wheezing and coughing, asthma and lung infections. Additionally, studies have found that young adults who use e-cigarettes experience arterial stiffness, impaired blood vessel function and increased blood pressure and heart rate. This evidence suggests that this could lead to cardiovascular disease in people who use e-cigarettes over the long term.
“While adolescents who use e-cigarettes may not feel that vaping is affecting them at the moment, it is increasingly clear that the chemicals contained within e-cigarette aerosols are harming cardiovascular cells, leading to changes that promote the development of heart disease over time,” Wold said. “It usually takes decades before people who smoke combustible cigarettes develop cardiovascular disease and/or chronic-obstructive pulmonary disease, and the same may be true of vaping. A reduction in adolescent vaping rates likely may help to improve long-term cardiopulmonary outcomes among this group.”
Studies have found that while some people may consider e-cigarettes as an aid to stop smoking combustible cigarettes, many people end up using both products regularly. The statement emphasized it is important to distinguish between tobacco cessation and nicotine cessation. One study from the United Kingdom, where the amount of nicotine in e-cigarettes is much lower than in the U.S., found e-cigarettes may be more effective than nicotine patches at combustible tobacco cessation (18% vs. 10%, respectively). However, the study found e-cigarettes were four times less successful in reducing nicotine consumption (20% for e-cigarettes compared to 81% for nicotine patches).
“The customizability of e-cigarettes, including power levels, e-liquid content and the abundance of flavors, appeals to young people and it also makes regulation of these products difficult,” Wold said. “While the FDA has issued a policy against mint and fruit flavors of e-liquids that are known to appeal to youth, for some product types, menthol flavored products are still available. Additionally, there is no regulatory standard limiting the concentration of nicotine in e-liquids in the U.S. Some devices have been found to have nicotine levels of 59 mg/mL. In comparison, the European Union limits nicotine concentration in e-liquids to less than 20 mg/mL, an amount comparable to that of standard combustible cigarettes.”
The statement recommended steps be taken to remove all flavored e-cigarettes, including menthol-flavored e-cigarettes, from the market. Additional public health and policy recommendations include:
• Implement better measures to reduce youth access to e-cigarettes, including strict age verification at place of sale and prohibiting marketing of e-cigarettes directed toward youth.
• Provide more education for youth and their parents regarding the confirmed and potential health risks of e-cigarette use.
• Establish vaping curricula for medical students to inform the next generation of health care professionals.
• Ensure hospital-based vaping-cessation programs exist for adolescents and adults.
• Regulate the marketing of e-cigarette products in traditional, online and social media platforms that are popular among youth.
• Incorporate e-cigarettes into smoke-free air policies.
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