Long-term use of electronic cigarettes, or vaping products, can significantly impair the function of the body’s blood vessels, increasing the risk for cardiovascular disease, two new studies suggest.
The findings, published in the journal Arteriosclerosis, Thrombosis, and Vascular Biology, demonstrate that the use of both e-cigarettes and regular cigarettes may cause an even greater risk than the use of either of these products alone.
E-cigarettes, also known as vapes, produce an aerosol by heating a liquid that usually contains nicotine flavorings. The aerosol is then inhaled into the lungs, according to the Centers for Disease Control and Prevention (CDC).
In the first study, researchers examined the blood samples of 120 volunteers, including those with long-term e-cigarette use, long-term cigarette smoking, and those who did not use any of these products.
Long-term e-cigarette users are those who vape more than five times per week for more than three months, while long-term cigarette users are individuals who smoke more than five cigarettes per day.
“In our human study, we found that chronic e-cigarettes users had impaired blood vessel function, which may put them at increased risk for heart disease,” said Matthew L. Springer, Ph.D., a professor of medicine in the Division of Cardiology at the University of California in San Francisco, and leader of both studies.
“It indicates that chronic users of e-cigarettes may experience a risk of vascular disease similar to that of chronic smokers.”
Researchers also discovered that e-cigarettes had harmful cardiovascular effects in ways that were different from those caused by tobacco smoke.
Specifically, they found that blood from people who smoked cigarettes had higher levels of certain circulating biomarkers of cardiovascular risks, and the blood of people who used e-cigarettes had elevated levels of other circulating biomarkers of cardiovascular risks.
No specific component
In the second study that included rats, researchers tried to find out if there were specific components of cigarette smoke or e-cigarette vapor that were responsible for blood vessel damage.
They exposed rats to nicotine, menthol (a cigarette additive), the gasses acrolein and acetaldehyde (two chemicals found in both tobacco smoke and e-cigarette vapors), and inert carbon nanoparticles to represent the particle-like nature of smoke and e-cigarette vapor.
The findings suggest that blood vessel damage is not caused by specific cigarette smoke or e-cigarette vapor component. Instead, researchers say, it appears to be caused by airway irritation that triggers biological signals in the vagus nerve that somehow leads to blood vessel damage, possibly through an inflammatory process.
“We were surprised to find that there was not a single component that you could remove to stop the damaging effect of smoke or vapors on the blood vessels,” Springer said. “As long as there’s an irritant in the airway, blood vessel function may be impaired.”
Previous evidence has indicated that e-cigarettes are less harmful than cigarettes, as they do not contain tobacco or involve combustion. Most e-cigarettes, however, contain nicotine, which is toxic to developing fetuses and can harm adolescent and young adult brain development.
Two studies from Johns Hopkins Medicine suggest that vaping increases the risk of asthma and chronic obstructive pulmonary disease (COPD), conditions known to be caused by smoking traditional cigarettes. For people who both vape and smoke tobacco regularly, the risk of COPD increases six times compared with those who do not use any tobacco products.
Despite mounting evidence of the harmful effects of e-cigarettes, they are widely used among the youth. A recent study from the CDC and the US Food and Drug Administration (FDA) found that in 2022, 14.1% of high school students and 3.3% of middle school students reported the use of e-cigarettes in the past 30 days.