London - E-cigarettes promoted as a way to quit smoking could pose a serious heart risk, a study warns.
A panel of experts assessed all available evidence about the safety of electronic cigarettes and said using them was not worth the danger.
They said: "E-cigarettes are not a harm-free alternative to tobacco smoke. Great caution and hesitation should remain concerning e-cigarette use until its health risk profile is better established."
Metals, particles and flavourings in the devices can increase blood pressure, heart rate and inflammation, and can stiffen the arteries, each of which raises the risk of heart disease, they said.
The conclusions by experts from Ohio State University reveal the gulf in the attitude towards e-cigarettes between the medical establishment in the US and that in the UK, where most experts see them as useful health tools.