Smoking both traditional and e-cigarettes may carry same heart risks as cigarettes alone

Smokers who think they can lower their risk for cardiovascular disease by sometimes smoking e-cigarettes instead of traditional ones might need to think again: A new study finds people who use both have the same cardiovascular disease risks as those who only smoke traditional cigarettes.

"The fact that dual use – using both traditional, combustible cigarettes and e-cigarettes – had similar cardiovascular disease risk to smoking cigarettes only is an important finding as many Americans are taking up e-cigarettes in an attempt to reduce smoking for what they perceive is a lower risk," senior study author Andrew Stokes said in a news release. Stokes is an assistant professor in the department of global health at Boston University School of Public Health.

"It is common for people to try to switch from traditional cigarettes to e-cigarettes and get caught in limbo using both products," he said.

Cigarette smoking and secondhand smoke exposure are responsible for nearly 1 in 5 deaths in the U.S. each year, according to American Heart Association statistics. In addition to heart disease and stroke, traditional cigarette smoking causes a wide range of health issues, including cancer and lung diseases. E-cigarettes contain many toxic chemicals, but how their long-term use affects heart health has not been well-studied.

The study, published Friday in the American Heart Association journal Circulation, used data from the Population Assessment of Tobacco and Health study, which collected information on health and nicotine use from 2013 to 2019. Researchers compared cardiovascular health for 24,027 traditional cigarette smokers, e-cigarette smokers and people who used both products. Nearly 1,500 cardiovascular events – heart attacks, bypass surgery, heart failure, stroke or other heart condition – were self-reported.

Researchers found no significant differences in heart attacks, heart failure or strokes among people who smoked a combination of traditional cigarettes and e-cigarettes, compared to those who smoked traditional cigarettes only. Those who exclusively used e-cigarettes were 30 to 40 percent less likely to report cardiovascular disease events; however, the number of heart-related events was too small for researchers to draw any solid conclusions.

While the study provides important information on the use of e-cigarettes and their impact on cardiovascular health, it relies on self-reported data over a short period of time "and the event rate is still low – especially in younger people," Dr. Rose Marie Robertson said in the release. She is co-director of the AHA's Tobacco Center of Regulatory Science, which supported the study.

Because e-cigarettes are still relatively new, there is still a need for more data and ongoing research to create a strong body of evidence on their long-term risks, she said. "It's important to remember that even with traditional cigarettes, decades of use and surveillance were needed to provide the strength of evidence we now have confirming the highly significant harm of combustible cigarettes. People should know that e-cigarettes contain addictive nicotine and toxic chemicals that may have adverse effects on their cardiovascular system and their overall health."

While that research continues, Stokes said people trying to quit should not move to e-cigarettes as a solution.

"Many smokers who attempt to use e-cigarettes for traditional cigarette smoking cessation actually continue using both products, becoming dual users, where we saw no reduction in cardiovascular risk," he said. "We are concerned that any recommendation of e-cigarette use for smoking cessation may lead to increased dual use, as well as e-cigarette initiation among young adults and those who have never smoked cigarettes."

Experts say people interested in quitting should speak with their health care team about Food and Drug Administration-approved options.