A new study has found that vaping has an immediate effect on how well the user’s blood vessels work, even if the e-cigarette doesn’t contain nicotine.

The research – which has not been published in a peer-reviewed journal, was presented at the annual meeting of the Radiological Society of North America in Chicago, taking place from December 1 -5.

The study 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.

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.”