Vaping could be as bad for your heart as smoking cigarettes, according to tests that found that e-cigarettes damage key blood vessels.
A professor told the world’s largest gathering of heart experts in Rome the devices are “far more dangerous than people realize.”
Top expert Professor Robert West, of University College London, said: “It would certainly be fair to say the study shows electronic cigarettes are not without any risk.
“The critical question is how much risk?”
Professor Peter Weissberg, medical director at the British Heart Foundation, said: “The study shows electronic cigarettes cannot be assumed to be risk-free.
“Much more research is needed to establish the safety of long-term use of these devices.”
Health officials last year claimed e-cigarettes were 95 percent safer than tobacco and doctors will soon be able to prescribe them alongside nicotine patches and gum to help smokers quit.
But trials have revealed vaping triggers levels of damage to key blood vessels similar to smoking tobacco. Known as arterial stiffness, it is the main predictor of heart disease.
University of Athens Medical School professor Charalambos Viachopoulos told the European Society of Cardiology Congress in Rome: “E-cigarettes are less harmful than traditional cigarettes but they are not harmless.
“There could be long-term heart dangers.”
“They are far more dangerous than people realize.”
“I wouldn’t recommend them now as a method to give up smoking. I think the UK has rushed into adopting this method.”
Scientists tested adults’ heart response after five minutes smoking cigarettes and during a typical 30-minute vaping session.
Vapers spend longer puffing than traditional smokers as the devices deliver nicotine at a slower rate.
The rechargeable gadgets sell for as little as $6.50 each. They give a nicotine hit but with no tobacco toxins.
Deborah Arnott, from quit-smoking charity ASH, insisted e-cigs were much safer than tobacco.
Rosanna O’Connor, director of drugs, alcohol and tobacco at Public Health England, agreed, saying: “Vaping carries a fraction of the risk of smoking.
“Yet many smokers are still not aware, which could be keeping people smoking rather than switching to a much less harmful alternative.”
And Tom Pruen, chief scientific officer from the Electronic Cigarette Industry Trade Association, said: “Lots of things have short-term effects on aortic stiffness and nicotine is already known to do this. This doesn’t appear to show anything new.”
E-cigs have been dogged by concerns over their effectiveness and fears they may introduce non-smokers to tobacco.
Fewer than one in 40 adults who switched to vaping to quit smoking in 2014 successfully kicked the habit.