Smoking e-cigarettes may not be much safer than tobacco when it comes to oral health, a new study suggests. Researchers found that e-cigarettes contain toxic substances and nanoparticles that could kill the top layer of skin cells in the oral cavity (behind teeth and gums).
Scientists from UCLA, who conducted the investigations on cultured cells, believe the same results could happen in a human study, increasing people’s risk of oral disease including cancer.
The latest findings add to a growing body of evidence linking the stop-smoking aids to health risks.
Just yesterday, researchers in North Carolina reported using the devices increases the risk of infection because it damages hundreds of genes in the immune system.
It follows a rapid rise in the use of e-cigarettes in recent years, especially among smokers trying to cut down or quit. The gadgets deliver a nicotine hit by heating a nicotine-containing propylene glycol (e-liquid) to create an aerosol (usually called ‘vapour’), which is inhaled.
The Centres for Disease Control found that 2.4 million middle and high school students were using e-cigarettes in 2014. Nearly one in six people in the UK have now used the devices – 15.5 per cent, up from 8.9 per cent two years earlier.
Doctors back e-cigarettes as an effective method of quitting smoking, with the NHS cleared this year to prescribe the devices for the first time.
But while the effects of conventional cigarette smoke on human health have been well-documented, research into e-cigarettes is still in its infancy. This is especially true when it comes to their effect on the oral cavity, they say.
The research team led by Dr. Shen Hu took cell cultures from the outermost layer of the oral cavity and exposed the cells to two different brands of e-cigarette vapour for 24 hours. The vapour, which contains varying amounts of nicotine or menthol, was generated by a machine built to ‘smoke’ cigarettes like a human would. The researchers then measured the particle concentration and size distribution of the simulated vapours.
They found that the vapours, which contain nanoparticles of metal, silica and carbon, varied in concentration depending on the e-cigarette brand and flavour.
Laboratory tests on cultured cell lines showed e-cigarette vapours may significantly weaken the oral cavity’s natural defence mechanism by decreasing the levels of an antioxidant glutathione.
This caused roughly 85 per cent of the tested cells to die.
Dr. Hu, an associate professor of oral biology at the School of Dentistry, said they were now looking to conduct the test on people.
“A small but significant portion of dental patients at UCLA Dental Clinics have used e-cigarettes, which will provide sufficient patient resources for our planned studies,” he said.
“Our hope is to develop a screening model to help predict toxicity levels of e-cigarette products, so that consumers are better informed.” Researchers suggest that healthcare providers should do more to raise public awareness of the products’ potential health risks.
The findings were published in the journal PLOS One. – Kate Pickles, Mailonline