Vaping may give rise to risk of particular cancers and heart disease as much as secondhand smoking, suggests a team of scientists who studied the effects of e-cigarette smoke on mice and human cells.
The researchers, led by Moon-shong Tang, professor of environmental medicine at New York University, found evidence that nicotine inhaled from e-cigarettes could be converted into chemicals that damage DNA in the heart, lungs and bladder, and dampen down the body’s genetic repair mechanisms, reported the Guardian.
The professor said the DNA changes were similar to those linked to secondhand smoke, but added that more work was needed to see whether vaping really did increase cancer rates.
However, other researchers dismissed the study as irrelevant to humans. The levels of e-cigarette smoke the mice were exposed to were very high and the effects may be very different in people who inhale nicotine from vaping, critics caution.
“This study shows nothing at all about the dangers of vaping,” said Peter Hajek, director of the Tobacco Dependence Research Unit at Queen Mary University of London. “It doesn’t show that vaping causes cancer.”
“This is one in a long line of false alarms which may be putting people off the switch from smoking to vaping which would undoubtedly be of great benefit to them,” he added. “The best current estimate is that vaping poses, at worst, some 5% of risks of smoking.”
Tobacco smoke contains thousands of chemicals and at least 70 are known either to cause or drive cancer in the body. The vapour from e-cigarettes contains far fewer toxic chemicals, with most of the smoke containing only nicotine, the addictive substance that gives users their hit.