Vaping could be as bad for the heart as smoking cigarettes, a new study suggests.
The findings triggered warnings that electronic cigarettes may be “far more dangerous” than was thought.
Trials found that a typical session using a device caused similar effects to the main heart artery as smoking a cigarette.
The research, presented at the world’s largest cardiology conference, comes amid growing controversy about the safety of e-cigarettes.
Last year Public Health England (PHE) endorsed vaping, claiming the habit was 95 per cent safer than smoking. GPs will soon be able prescribe them to help smokers who are trying to give up.
Researchers at the European Society for Cardiology congress in Rome said such steps were premature – and that they would not encourage the use of the devices.
British heart experts said the findings were important, and said much more research was needed to examine the long-term safety of e-cigarette use.
The trial involved a group of adult smokers, whose hearts were monitored while they vaped, and when they smoked ordinary cigarettes.
Researchers said a a typical vaping session had a similar impact on stiffness of the aorta – the main artery into the heart – as smoking one regular cigarette.
Lead researcher Prof Charalambos Vlachopoulos, from the University of Athens Medical School said: “We measured aortic stiffness. If the aorta is stiff you multiply your risk of dying, either from heart diseases or from other causes.”
The unfavourable effects shown from a 30 minute session vaping – described by researchers as a typical habit – were similar to those from five minutes’ smoking a cigarette, the study found.
“The aorta is like a balloon next to the heart,” he said. “The more stiff the balloon is, the more difficult for the heart to pump. It’s the most powerful biomarker we have for estimating cardiovascular risk.”
The experiments, which involved 24 adults with an average age of 30, only examined the immediate effects of e-cigarettes and smoking.
The cardiologist said the long-term risks of vaping remain unknown – but that he would not recommend their use.
”The value of the acute study is that it gives an insight of how long your aorta is stressed throughout the day – because this happens throughout the day, this is something that happens repeatedly,” he said.
“There could be long term heart dangers. They are far more dangerous than people realise.”
He criticised PHE’s stance on e-cigarettes.
“I wouldn’t recommend them now as a method to give up smoking. I think the UK has rushed into adopting this method,” he said.
Office of National Statistics data shows a record 2.2million Brits regularly used e-cigarettes in 2015.
Prof Peter Weissberg, medical director at the British Heart Foundation, said: “This important study tries to determine if e-cigarette smoking has any harmful effects on our blood vessels.
He said: “The findings show that electronic cigarettes have a similar effect to normal cigarettes on the stiffness of the main blood vessel in the body.
“Although the study was not designed to show whether electronic cigarettes can cause long term damage to our blood vessels, it shows that [they] cannot be assumed to be risk free.
“Much more research is needed to establish the safety of long term use of these devices.”
However, Deborah Arnott, chief executive of Action on Smoking and Health, said: “This study does not prove that e-cigarettes are as hazardous as smoking.” She highlighted other findings from the study, showing that if a vaping session was limited to five minutes, the impact on aortic stiffness was significantly less than that associated with a cigarette.
Tom Pruen, chief scientific officer for 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. On the other hand, so does caffeine, and in both cases it is transitory, without any significant long term effect.”
Rosanna O’Connor, from Public Health England, said: “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.”