Even nicotine-free e-cigarettes can harm blood flow, study finds

A study by the University of Pennsylvania examined the effects of nicotine-free e-cigarettes on blood vessels. Thirty-one non-smoking participants inhaled e-cigarettes containing propylene glycol, glycerol, and flavoring. MRI scans revealed a 30% constriction in blood vessels, reducing oxygen flow by 20%. Lead author Alessandra Capparelli emphasized that e-cigarettes are not equivalent to inhaling water vapor, even without nicotine.

What percentage reduction in oxygen flow was observed in the blood vessels after vaping?

According to the lead author, how does the usage of e-cigarettes compare to inhaling water vapor?