Dangerous substances in electronic cigarettes damage the protective layer of the lungs

Vitamin E acetate and some other substances in e-cigarette liquids deform and weaken the protective lipid layer inside the lungs. This was found by scientists from J. Heyrovský Institute of Physical Chemistry of the CAS in collaboration with the University of Helsinki. The study is published in the journal Scientific Reports in Nature.

Dozens of people died in the United States a few years ago from smoking electronic cigarettes, known as vaping, and thousands more suffered health problems. In 2019, scientists have been able to shed light on these mysterious deaths linked to electronic cigarettes. They found that the main cause of lung damage was vitamin E acetate (tocopherol acetate) contained in e-cigarette refills, called liquids. As a result, the use of tocopherol acetate in liquids was stopped. However, various substances such as preservatives, colourings and flavourings, some of which have similar properties to tocopherols, continue to be added to liquids.

Tocopherol changes surface pressure

Scientists from the J. Heyrovsky Institute of Physical Chemistry of the CAS, in collaboration with the University of Helsinki, investigated how tocopherols affect the lungs at the molecular level. And they have discovered why vitamin E is harmful in the lungs, while it is beneficial to health when taken in other ways, e.g. orally.

For the research, the researchers used porcine surfactant, which is a protein-lipid layer on the surface of the lung's alveoli that is important for proper lung function. They spread samples of surfactant at the water-air interface, similar to that naturally present in the lungs, allowed tocopherol to act on it, and monitored the surface pressure as the sample expanded and contracted to mimic breathing. They found that the surface pressure would increase sharply. 

"We also examined the samples under a fluorescence microscope. We saw that when tocopherol was added to the sample, deformations and clusters of molecules were formed at the exact moment when the surface pressure started to increase, which means that tocopherol was incorporated into the surfactant layer," says research leader Lukasz Cwiklik from J. Heyrovský Institute of Physical Chemistry of the CAS.

Even the base of liquids is harmful

The researchers decided to test their final summary in e-cigarette experiments. They used different types of liquids, mimicked smoking an e-cigarette, and monitored changes in surface pressure of the surfactant after a period of smoking. Again, the surface pressure was shown to increase sharply when using a liquid containing tocopherol. But the researchers came to another conclusion, and it is alarming. When they used liquids that are commonly sold but do not contain tocopherol, the surface pressure also changed - but in this case it decreased.

“This implies that even the base components of e-liquids may have an adverse effect on the lungs,” explains Lukasz Cwiklik.

The research provides new molecular insights into the dangers of additives in vaping products. People should be particularly cautious when they prepare their own vaping liquid blend with ingredients not normally used for vaping.