E-cigarettes, which release a vaporised dose of liquid nicotine without smoke or tobacco, have been stirring up hot debate over their safety, with some experts urging that they be pulled from the shelves.
As part of the latest study, researchers from the University of Athens recruited eight people who had never smoked and 24 smokers, 11 with normal lung function and 13 with either asthma or chronic obstructive pulmonary disease.
Each subject used an e-cigarette for 10 minutes, with researchers then measuring their airway resistance using a number of tests.
For all of the subjects, the e-cigarette sparked “an immediate increase in airway resistance” in at least one test, said study author Christina Gratziou. She said this “suggests e-cigarettes can cause immediate harm after smoking the device”.
Because the long-term effects are unclear, the scientists say more research needs to be done.
Ms Gratziou presented the research at the European Respiratory Society’s annual congress in Vienna.
She said: “We do not yet know whether unapproved nicotine delivery products, such as e-cigarettes, are safer than normal cigarettes, despite marketing claims that they are less harmful.
“This research helps us to understand how these products could be potentially harmful.”
“The electronic cigarette is not a proven nicotine replacement therapy,” Dr Ala Alwan, assistant director general for noncommunicable diseases at the World Health Organisation has said.
“WHO has no scientific evidence to confirm the product’s safety and efficacy.
“Its marketers should immediately remove from their websites and other informational materials any suggestion that WHO considers it to be a safe and effective smoking cessation aid,” Dr Alwan said.
But it’s not all bad news: a recent study led by Boston University School of Public Health researchers reports e-cigarettes are a promising tool to help smokers quit, producing six-month abstinence rates nearly double those for traditional nicotine replacement products.
Last month a study found e-cigarettes do not appear to pose a threat to the heart.
“Electronic cigarettes are not a healthy habit but they are a safer alternative to tobacco cigarettes,” Dr Konstantinos Farsalinos from the Onassis Cardiac Surgery Centre in Athens told the annual meeting of the European Society of Cardiology.
“Considering the extreme hazards associated with cigarette smoking, currently available data suggest that electronic cigarettes are far less harmful and substituting tobacco with electronic cigarettes may be beneficial to health,” Dr Konstantinos said.