Two common vaping flavours found to greatly increase risk of heart disease

28 May 2019

Image: © Innovated Captures/

Researchers have found that the flavourings sold for e-cigarettes are damaging the human body at a cellular level.

Those vaping various flavours through their e-cigarettes may need to rethink their decision if a new study is anything to go by.

Researchers from the Stanford University School of Medicine published findings to the Journal of the American College of Cardiology revealing that these liquid flavours may increase the risk of cardiovascular disease when inhaled.

The research looked at the effect these e-liquids had on endothelial cells, which line the interior of blood vessels. When grown in a lab, endothelial cells exposed to the vaping liquid – or blood from an e-cigarette user shortly after inhaling – showed significantly increased levels of DNA damage and cell death. The cells were also shown to be less able to form new vascular tubes and heal wounds.

Interestingly, the severity of the damage appears to vary among the most popular flavours, even in the absence of nicotine. Over the course of the study, the researchers identified cinnamon and menthol as being the most harmful to endothelial cells.

“Until now, we had no data about how these e-liquids affect human endothelial cells,” said Joseph Wu, director of the Stanford Cardiovascular Institute and professor of cardiovascular medicine and of radiology.

“This study clearly shows that e-cigarettes are not a safe alternative to traditional cigarettes. When we exposed the cells to six different flavours of e-liquid with varying levels of nicotine, we saw significant damage. The cells were less viable in culture and they began to exhibit multiple symptoms of dysfunction.”

‘E-cigarettes can be deceptive’

Over the course of the study, six different vaping flavours were tested: fruit, tobacco, sweet tobacco (with caramel and vanilla), sweet butterscotch, cinnamon and menthol. The latter two significantly decreased the viability of the cells in culture and disrupted the ability of the cultured cells to form capillary-like tubular structures associated with the growth of new blood vessels.

The cells exposed to cinnamon flavour as well as the caramel and vanilla showed an increased uptake of low-density lipoproteins and lipids – processes commonly associated with inflammation and endothelial dysfunction – and a reduction in their ability to migrate to heal wounds or scratches.

A final experiment tested the levels of nicotine in the blood serum of people after they had vaped and compared them with people who had smoked traditional cigarettes. This showed that the amount of nicotine in the blood was similar between both groups after 10 minutes of smoking at a constant rate.

“When you’re smoking a traditional cigarette, you have a sense of how many cigarettes you’re smoking,” Wu said. “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.”

A survey last year showed that 4pc of the Irish population use e-cigarettes, while a study published in March of this year by the FDA showed that US teenagers are more likely to use sweet-flavoured e-cigarettes such as those implicated in the Stanford study.

Colm Gorey was a senior journalist with Silicon Republic