• Researchers say e-cigarettes and tobacco cigarettes have similar negative health effects on a person’s cardiovascular system.
  • They add that smoking and vaping at the same time have even serious effects on heart health.
  • They say that both vaping and smoking cause airway irritation.

A pair of studies released today – one on humans, the other on rats – show similar cardiovascular effects from cigarettes and e-cigarettes.

The findings also indicate that smoking and vaping together produce even more serious heart health issues.

Researchers reported that the effects on blood vessel function are probably caused by airway irritation from inhaling a foreign substance, instead of specific components of cigarette smoke or e-cigarette vapor.

The studies were published in late October in the American Heart Association’s peer-reviewed journal Arteriosclerosis, Thrombosis and Vascular Biology.

“The goal of this project was to determine why a growing number of inhaled tobacco products, including combustible cigarettes, heated tobacco products, and e-cigarettes, all impair endothelial function despite fundamental differences in these products,” said Matthew L. Springer, PhD, the lead researcher on both studies and a professor of medicine in the cardiology division at University of California San Francisco, in a statement.

“Thousands of chemicals have been identified in tobacco smoke, some of which are also present in e-cigarette aerosols, either as an original ingredient or as a chemical reaction product of the heating process,” Dr. Springer said. “We sought to find which specific component of smoke or e-cigarette vapor may be responsible for interfering with blood vessels’ ability to function efficiently.”

Another study published in mid-November concluded that both tobacco and marijuana smoking can increase the risk of developing arrhythmias.

Both cigarettes and e-cigarettes cause endothelial dysfunction, the inability of the large blood vessels to open enough to supply sufficient blood to the heart and other tissues. That condition can be an early predictor of cardiovascular diseases.

Springer’s team reported that impairment of endothelial function by cigarette smoke isn’t caused by a specific smoke constituent but by vagal input from the airway.

In the rat study, arterial flow-mediated dilation (FMD) – the ability of the blood vessels to widen – was measured pre-exposure and post-exposure to smoke from four kinds of traditional combustible cigarettes: conventional nicotine, reduced nicotine, conventional nicotine with added menthol, and reduced nicotine with added menthol.

Menthol is added to many tobacco products and may decrease irritation caused by smoking and may play a major role in facilitating nicotine addiction.

The study found blood vessel dilation was reduced by all four types of cigarettes, ranging from 20% to 46%. Higher nicotine levels were associated with a greater decrease in FMD and menthol was associated with a lower decrease in FMD.

Springer said that shouldn’t suggest menthol is a beneficial additive in smoking and vaping products, as impairment was still substantial and menthol has other harmful effects.

“This study confirms, yet again, what we doctors have known for years: that smoking cigarettes is harmful to your lungs and heart,” Dr. Robert Goldberg, a pulmonologist with Providence Mission Hospital in Southern California, told Healthline. “While vaping was initially considered to be a safer option to help people quit smoking, the aerosol ingredients have not been evaluated by the U.S. Food and Drug Administration.

“And, the e-cigarette liquid, when heated, is a potent vasoconstrictor or blood pressure increasing drug and delivers nicotine extremely quickly to your body. This creates a serious health risk to both your lungs and your heart,” he added.

Goldberg said the original thinking was vaping was safer because someone wasn’t breathing in harmful smoke.

“But we don’t know the exact chemical makeup of the vaping liquid,” he explained. “What we do know is that other ingredients and chemical compounds found in the liquid have their own health risks. We’re only beginning to understand the toxic side effects that breathing in e-cigarette vapors can have on our lungs and heart.”

The rats were also exposed to two main gases found in smoke and aerosol, as well as clean carbon nanoparticles, to evaluate the effects on blood vessel dilation.

The gases and carbon particles showed similar impairment to whole tobacco smoke, despite representing completely different chemical and physical components of smoke.

“We were surprised to discover that it’s not a specific foreign material being inhaled that causes harmful cardiovascular effects. It’s the fact that some kind of irritant is being inhaled in the first place, regardless of what it was,” Springer said. “All inhaled products are likely to have similar harmful effects on vascular function.”

That could mean there’s less of a difference in harm between vaping and smoking, Patricia Folan, RN, the director of the clinical program at Northwell Health Center for Tobacco Control, told Healthline.

“It has been documented that many adults are dual users of combustible and e-cigarettes,” she said. “According to the study, this presents an even greater health hazard than using either one alone.”

“This information is important to share with the public who may think they are helping themselves by cutting back on regular cigarettes and substituting a vape product while using both at the same time,” Folan said.

Dr. Thomas Yadegar, a pulmonologist and medical director of the ICU at Providence Cedars-Sinai Tarzana Medical Center in California, told Healthline that “any type of inhalational agent, no matter the origin, has an effect on the blood vessels within the airways. This is the foundational premise of administering inhaled medications.”

“Whereas inhalers and nebulizers seek to dilate airways via blood vessels, inhaling smoke, vapors, dust or other environmental triggers can start a cascade of inflammation,” Yadegar said.

Springer said the lack of a specific toxin accounting for vascular impairment means regulatory agencies cannot rely on prohibiting specific ingredients to avoid adverse effects of inhaled products.

The second study found that prolonged vaping and cigarette smoking both cause changes in the blood that affect endothelial function, although in differing ways.

“Our findings suggest that vaping, although not smoking combustible cigarettes, causes changes in the blood that increase the potential for leakage in the blood vessels and that both smoking and vaping cause changes in the blood that lead to endothelial dysfunction and an increased risk of future cardiovascular events in otherwise healthy people,” Springer said.

“It’s important for regulators, clinicians, and the public to realize that vaping is not harmless,” he added. “Smoking and vaping can have similar harmful cardiovascular effects, but each condition causes some potentially harmful effects that the other does not. These differences indicate that dual product use, meaning smoking combustible cigarettes and also using e-cigarette products, may actually be worse for vascular health than either smoking or vaping alone.”

Doctors say that however you interpret the studies, quitting smoking and vaping are the best ways to manage the danger.

We know that the evidenced-based way to quit smoking is through ‘quit coach’ counseling paired with nicotine replacement therapy (e.g., patch, gum, lozenge, etc.) sold at your local drug stores over the counter,” Mary Martinasek, a respiratory therapist and associate professor in public health at the University of Tampa in Florida, told Healthline.

“This method is the only evidenced-based approach to quitting,” Martinasek said. “Smokefree.gov outlines this information. Many states, such as Florida, offer these products free of charge and ‘quit coach’ counseling free of charge.“

“If it is for a teen, the American Academy of Pediatrics has advised doctors to prescribe the nicotine replacement therapies to those younger than age 18,” she added.