Scientists now say that vaping affects blood vessels within minutes, even including nicotine-free vapes. Experts warn these changes could lead to long-term health problems, like blood clots, heart attacks and strokes. The ingredients in vapes may also cause inflammation affecting the entire body.

"This study serves to highlight the acute effects smoking and vaping can have on a multitude of vascular beds in the human body," Dr. Nabbout said. "If the acute consumption of an e-cigarette can have an effect that is immediately manifested at the level of the vessels, it is conceivable that the chronic use can cause vascular disease."

Decreased venous oxygen saturation was also present in vapers whether or not the e-cigarettes contained nicotine.

New study reveals vaping and smoking's immediate effects on vascular health, challenging safety claims of e-cigarettes.

A cuff was placed on their upper thigh to restrict blood flow. Once it was deflated, researchers measured the speed of blood flow in the large, femoral artery and how much oxygen in the blood returned to the heart after supplying it to tissues.