Electronic cigarettes, or e-cigs, may be just as bad for the cardiovascular system as traditional cigarettes, according to a study published Wednesday in the Journal of the American Heart Association. Researchers found that both vaping and smoking cigarettes cause a similar amount of damage to arteries and blood vessels. 

In recent years, millions of teenagers and young adults have started vaping regularly. In a press release accompanying the study, co-author Jessica Fetterman said many of these vapers believe e-cigarettes are safer than traditional, combustible cigarettes. 

"Meanwhile, the evidence from scientific studies is growing that e-cigarettes might not be the safer alternative to smoking traditional cigarettes when it comes to heart health," she said. "Our study adds to that evidence." 

The study followed more than 400 men and women aged 21 to 45 who have not been diagnosed with heart disease and are not at risk for heart disease. Researchers found that the 285 people who smoke traditional cigarettes and the 52 people who smoke both traditional and e-cigarettes were more likely to be older than those who don't smoke or only vape. E-cigarette users, researchers found, were more likely to be younger white males. 

The researchers discovered that all of those who used e-cigarettes had arteries just as stiff as those who smoke traditional cigarettes. 

"Stiffening of the arteries can cause damage to the small blood vessels, including capillaries, and puts additional stress on the heart, all of which can contribute to the development of heart disease," Fetterman said.