TWO popular flavours of e-liquid may be putting vapers at significant risk of deadly heart attack or stroke, experts are warning.
Cinnamon and menthol have been found to be “particularly harmful” to heart health.
Scientists have found that when blood vessel cells are exposed to e-liquid, they start to exhibit “significantly increased levels” of DNA damage and cell death.
But the new study found that the severity of that DNA damage depends on the flavour of the vape juice – with cinnamon and menthol causing the most damage.
Cinnamon and menthol are the worst
“Until now, we had no data about how these e-liquids affect human endothelial cells,” said study senior author Professor Joseph Wu, of Stanford University School of Medicine.
“This study clearly shows that e-cigarettes are not a safe alternative to traditional cigarettes.
“When we exposed the cells to six different flavors of e-liquid with varying levels of nicotine, we saw significant damage.”
The cells, known as endothelial cells, line the surface of the blood vessels and play a critical role in heart health.
“Significantly increased” cell damage
Scientists looked at six different popular e-cig flavours: fruit, tobacco, sweet tobacco with caramel and vanilla, sweet butterscotch, cinnamon, and menthol.
They also varied the levels of nicotine present, including: zero, six, and 18 milligrams per millilitre.
They found that many of the liquids were “moderately toxic” to the cells, while the cinnamon and menthol flavours “significantly increased” cell damage, even without nicotine.
We previously revealed that two other popular flavourings – caramel and popcorn – have also been found to destroy lung function.
The findings, published online by the Journal of the American College of Cardiology, showed that e-liquid flavoured with caramel and vanilla also disrupted growth, but not as severely.
The cells exposed to cinnamon flavour and caramel and vanilla flavours exhibited an increased uptake of low-density lipoproteins and lipids – processes often linked with inflammation and endothelial dysfunction – and a reduction in their ability heal wounds or scratches.
Experts also compared the levels of nicotine in the blood serum of people after they vaped with those who smoked tobacco cigs.
E-cigs are “deceptive”
They found that the amount of nicotine in the blood was similar between the two groups after ten minutes of smoking at a constant rate.
The study’s co-lead, Dr Won Hee Lee, Assistant Professor at the University of Arizona, said: “When you’re smoking a traditional cigarette, you have a sense of how many cigarettes you’re smoking.
“But e-cigarettes can be deceptive. It’s much easier to expose yourself to a much higher level of nicotine over a shorter time period.
“And now we know that e-cigarettes are likely to have other significantly toxic effects on vascular function as well.”
He added: “It’s important for e-cigarette users to realise that these chemicals are circulating within their bodies and affecting their vascular health.”
Not the first damning study
This study isn’t the first one to suggest that e-cigs aren’t as safe as some suggest.
Despite the fact that vapers are three times more likely to quit than smokers who use nicotine replacement products, scientists have said that there’s not enough evidence to confirm that e-cigs are truly safe.
Professor Martin McKee from the London School of Hygiene and Tropical Medicine has said that he has “serious concerns” about the safety of vape pens.
Prof McKee claims that PHE is choosing to promote vaping whilst wilfully ignoring the potential dangers – despite the fact that nearly 16 per cent of teens report having tried e-cigs.
“The nicotine in e-cigarettes is not a harmless drug and then there are all these other things such as flavourings that are inhaled,” he said.
“We haven’t had e-cigarettes for long enough to know the true effects. But when we look at the evidence we do have, there are enough grounds for serious concerns.
“Given the short-term effects on lung function and cardiovascular effects, there is enough evidence to say we should be very, very careful.”
We previously revealed that millions of vapers are at higher risk of heart attack and stroke, with vaping increasing the risk by as much as 71 per cent.
Miranda Larbi/The Sun