Paris (AFP)

Electronic cigarettes could have harmful effects on the cardiovascular system, according to a study published Thursday, which considers premature to consider them as "a safe alternative" to cigarettes.

"E-cigarettes contain nicotine, fine particles, metals and flavorings, it's not just harmless water vapor," says lead author Loren Wold of Ohio State University (USA).

"Air pollution studies show that fine particles (less than 2.5 microns) enter the bloodstream and have an effect on the heart, and e-cigarette data points in this direction," he says. -he.

This study, which compiles previous work on the subject, is published in the European Society of Cardiology (ESC), Cardiovascular Research.

The authors point to the action of nicotine, which increases blood pressure and heart rate, as well as fine particles, which can cause hardening of the arteries and inflammation.

All these effects suggest that "the chronic use of e-cigarettes could increase the development of cardiovascular diseases", judge the authors of the study.

They ask for more studies on the flavors contained in vaping liquids: "If most are deemed safe when ingested, their effects are little known when inhaled".

In addition, the authors of the study call for more work on the use of electronic cigarettes over a long period, while it is its use in the short term that is most often studied.

This study is one more episode in the long controversy around electronic cigarettes.

On the one hand, health authorities such as the World Health Organization (WHO) consider that they can not be considered as a tool for preventing smoking because of the lack of perspective on their potential effects.

This position makes the pro-vaping camp, to which most tobacco specialists belong, jump.

Because for people who already smoke, a scientific consensus exists on the fact that it is less harmful to vapot than to smoke tobacco: the nicotine remains, but the carcinogenic substances present in the cigarettes are no longer inhaled.

Indeed, vaping consists in inhaling vapors created by heating, not burning, a liquid that contains mostly nicotine, highly addictive but not carcinogenic.

This controversy has swelled in recent months because of the mysterious outbreak among vapers in the United States. It has so far killed 37 people and nearly 1,900 severe pulmonary patients, according to the latest report from the US Centers for Disease Control and Prevention (CDC).

In three quarters of cases, American patients have consumed in their electronic cigarette products THC, the psychoactive agent of cannabis, often bought illegally. But the exact causes of the epidemic are still unknown.

© 2019 AFP