If you’re a cigarette smoker looking to quit, e-cigarettes, also known as vape pens, may seem like a good alternative.

Battery-operated or rechargeable e-cigarettes do not contain any tobacco. Instead, a cartridge of liquid nicotine, flavorings and other chemicals is heated to make a vapor, which is then inhaled by the user. The ease of use, lack of ash and smoky odor and variety of flavors make these electronic nicotine delivery systems appealing to many people, including teenagers.

But a study presented at the 2019 American Heart Association Scientific Sessions concludes that using e-cigarettes may carry as much risk for heart disease—and maybe even more—as traditional tobacco cigarettes.

This finding comes at a time when, despite increased reports of lung-related e-cigarette injuries, manufacturers continue to claim that these electronic systems are safe and can help cigarette smokers to quit. 

New study: Researchers at the Smidt Heart Institute at Cedars-Sinai Medical Center in Los Angeles measured blood flow to the heart—a marker of how well the heart is functioning—of regular smokers ages 18 to 38 before and after smoking either e-cigarettes or traditional cigarettes. The measurements were taken while the participants were at rest and after they performed a handgrip exercise. The tobacco cigarettes caused blood flow to decrease after physical stress, but not while at rest. The e-cigarettes, however, caused impaired blood flow both after physical stress and while at rest. Decreased coronary blood flow increases the risk for heart disease.

“It’s not just the nicotine that makes e-cigarettes harmful to the heart and lungs. It’s the completely unknown bucket of manufactured products used to form vapors that is likely causing the most harm,” said senior study author Florian Rader, MD, MSc, medical director of the Human Physiology Laboratory at the Smidt Heart Institute. Note: The Centers for Disease Control and Prevention recently identified vitamin E acetate as a “very strong culprit” in lung injuries related to vaping.

And because e-cigarettes are associated with blood flow dysfunction not just during physical stress but at rest as well, they may be even more harmful than traditional cigarettes, despite what their distributors would like you to believe, the study reports.

The researchers add that because the practice of vaping is still relatively new, scientists may not yet know all of the ways it can damage hearts and lungs. Dr. Rader advises, “The use of any electronic nicotine delivery system should be considered with a high degree of caution until more data can be gathered.”

Bottom line: At this point, we need to assume that cigarettes of any kind may hurt your health. If you don’t smoke or vape, don’t start. If you need help quitting, you can find useful tools and tips at SmokeFree.gov.