The question

People sometimes opt for electronic cigarettes in hopes of escaping the proven health hazards of tobacco, which include an increased risk for heart disease. Are e-cigarettes in fact harmless when it comes to the heart?

This study

The study involved 42 adults with an average age of 28. Twenty-three had used e-cigarettes — vaped — daily for at least a year and 19 had never vaped.

All participants had no known health problems, were taking no prescription medications and did not smoke tobacco cigarettes. Electrocardiograms and blood tests were used to evaluate their heart activity. E-cigarette users were found to exhibit physiological effects not present in the nonusers, such as abnormalities in cardiovascular function that included higher oxidative stress levels and levels of adrenaline in the heart, an effect known as increased cardiac sympathetic activity. These factors are known to increase the risk of cardiovascular problems.

Who may be affected?

People who are habitual users of e-cigarettes, battery-operated devices that heat a liquid containing nicotine, flavorings and various chemicals. The resulting vapor is then inhaled by the user. Some people see e-cigarettes as a way to rein in the use of tobacco cigarettes. Others see them as providing another means to lure people into nicotine addiction and possibly encourage their transition to tobacco products.


The study involved a small number of people and investigated only cardiovascular effects. It involved steady, longtime users of e-cigarettes; whether the findings would apply to occasional users was not tested.

Find this study

Online in JAMA Cardiology (click “New Online”).

Learn more

Information on e-cigarettes is available at drugabuse.gov.