Vaping has an immediate effect on how well the user’s blood vessels work, even if the e-cigarette doesn’t contain nicotine, according to new research.

The research – which has not been published in a peer-reviewed journal but is a presentation at the annual meeting of the Radiological Society of North America in Chicago – showed that using an e-cigarette with or without nicotine also decreased a metric known as venous oxygen saturation, which may mean the person’s lungs were taking in less oxygen.

More research will be needed to corroborate the findings and study the effects in the long term. But scientists say these results may mean that vaping regularly could lead to vascular disease down the road.

“People mistakenly believe that electronic cigarettes are safer alternatives to tobacco-based cigarettes, but this is actually not true,” said Dr. Marianne Nabbout, lead author of the study and a radiology resident at the University of Arkansas for Medical Sciences in Little Rock, who did the research at the University of Pennsylvania.

Although e-cigarette aerosols don’t have the same cancer-causing contaminants as tobacco smoke, people still breathe in chemicals when they vape, and this study shows that it has an effect on the body.

E-cigarettes work by heating liquid that turns into a vapor that is inhaled by the user. But the vapor contains more than just water; depending on the device, it may also include substances like lead, nickel, formaldehyde, propylene glycol and glycerin.

“Even if there was no nicotine in the e-cigarette, there could be other components that may be harmful,” Nabbout said. “That is why I think we saw these significant effects, even when the subjects were not choosing the nicotine-based electronic cigarette.”

Nabbout and her colleagues looked at what happens to the bodies of cigarette smokers, e-cigarette vapers and vapers who used products without nicotine. They enrolled 31 smokers and vapers ranging in age from 21 to 49, comparing their results with those of 10 people who did not smoke or vape.

Each participant got MRI scans before and after vaping or smoking, or at each visit for the nonsmokers. The researchers also put a cuff on each person’s upper thigh to restrict blood flow; once the cuff was deflated, they evaluated the speed of blood flow in the femoral artery and measured the amount of oxygen in the blood returning to the heart after it supplied oxygen to the body’s tissues.

Each time someone vaped or smoked, the researchers saw a significant decrease in resting blood flow velocity in the femoral artery, which runs along the thigh and supplies oxygenated blood to the entire lower body.

Compared with the nonsmokers and cigarette smokers, the people who used vapes with nicotine had the most significant reduction in vascular function. The group with the next greatest change was those who used vapes without nicotine.

Good vascular function is important because it means a person’s blood vessels are able to expand and contract so their blood can flow efficiently, delivering oxygen and nutrients to the body and removing waste. Poor vascular function could lead to problems like blood clots, high blood pressure and stroke.

The research also showed that all of the people who vaped – with or without nicotine - had decreased oxygen saturation, meaning their lungs were probably taking in less oxygen.

Nabbout said the goal of the study is to help regulators as they make decisions about which of these products should stay on the market in the United States.

E-cigarettes have been on the market without regulation for years, but to stay there, companies need authorization from the US Food and Drug Administration, which is considering millions of product applications.

Some doctors used to recommend e-cigarettes to help people quit smoking, and the manufacturers have made that argument to the FDA, but studies have shown that e-cigarettes do not help people quit.

The FDA has authorized a few vaping products, but none is specifically approved as a harm-reduction device.

Dr. Albert Rizzo, chief medical officer for the American Lung Association, says the new research adds to the growing body of evidence showing that vaping exposes people to a lot more than harmless water vapor.

“We don’t know a whole lot about the effects of the ingredients of e-cigarettes with regard to effects on our lungs, effects on our blood vessels, and even though there is supposedly less toxins than a regular cigarette, we don’t know the long-term effects of these modalities are. Tests like these keep showing there are short-term effects,” said Rizzo, who was not involved with the new study.

Rizzo said he found it interesting that both the nicotine and non-nicotine vapes had an effect.

“That’s telling us that something in these ingredients are likely causing airway irritation that leads to inflammation, and that inflammation spills over to the rest of the body the same way we know particle pollution does,” he said.

Research shows that exposure to air pollution known as particle pollution can lead to higher incidence of heart attacks and other significant health problems. If vaping is significantly affecting someone’s vascular health, e-cigarette users could then see increased heart attacks, strokes or blood flow issues, Rizzo said.

“At the Lung Association, we definitely don’t want young people who attracted by the different flavors that are on the market to start using these,” Rizzo said.