How dangerous are e-cigarettes?

E-cigarettes were to be used as a means to quit smoking. But now researchers are linking them to health risks. Yet the market continues to flourish – and many of the users are young.

Man holds e-cigarettes in his hand.
Photo: iStock

Name: Magnus Lundbäck

Work as: Docent in Cardiology at Karolinska Institutet and physician at Danderyds sjukhus.

Magnus Lundbäck. Photo: Oskar Omne

Text: Maja Lundbäck, first published in Medicinsk Vetenskap nr 3/2019
Photo: Oskar Omne

Your research on e-cigarettes has gained a lot of attention internationally, but not in Sweden. Why is this?

“E-cigarettes are still uncommon here. We’re trailing pretty far behind as it only became legal to sell over the counter in 2016. Only two per cent of the population are users. In the United Kingdom it is much more common, and in the USA the market is exploding, including among young people. E-liquid, which is poured into the e-cigarette container where it is evaporated, is sold in a thousand flavours – not only cigarette flavour but also candy flavour and an appalling number of other flavours that have been developed to entice young people and children. Most e-liquids contain nicotine.”

Regular smoking increases the risk of cardiovascular disease. What about e-cigarettes?

“Regular smoking causes chronic arterial stiffness, and the stiffer the arteries, the greater the risk of a heart attack and stroke. When we exposed people to e-cigarettes, we could observe that arterial stiffness increased temporarily. The stiffness was apparent following e-cigarettes with nicotine, but not without, so we think that it is the nicotine that is harmful to the arteries. We also looked for a type of stem cell, EPC cells, whose task in the body is vascular repair. After a heart attack, they tend to increase sharply in number. And we noted that these cells increased after e-cigarette use, which may indicate vascular irritation or damage.”

Is it only nicotine that is dangerous?

“There are other harmful substances in e-cigarettes besides nicotine. For obvious reasons, long-term studies are lacking, but by extracting respiratory cells from individuals, we were able to expose them to e-cigarette vapour for an extended period. We then observed that the cells exhibited impaired function but also that there was damage to the DNA. When we did an analysis of the e-cigarette vapour, we saw that it contained many harmful particles but also some levels of so-called polycyclic aromatic hydrocarbons, which may potentially have carcinogenic effects.”

How much better are e-cigarettes compared to regular cigarettes?

“Because regular cigarettes are so very dangerous, it is probably less dangerous with e-cigarettes. Within the tobacco industry, it is believed that e-cigarettes can be used as a way to quit smoking, but it is doubtful whether this works. Our findings suggest that they do not and that most people intending to quit smoking instead end up using both regular cigarettes and e-cigarettes.”

Does e-cigarette use risk leading to worse dependencies?

“Nicotine is a very addictive substance, so there is a fear that e-cigarettes could act as a gateway to tobacco cigarettes, marijuana and other drugs.”