New research adds to the mounting evidence of the harmful effects of e-cigarettes: cinnamon, vanilla and butter flavors are among the most toxic
Sugar and spices are good for eating, but not so good for inhaling or vaping. Exposure to the chemicals and flavoring liquids from e-cigarettes can cause significant inflammation of monocytes, a type of white blood cell. Many flavorings are also toxic, the worst being cinnamon, vanilla, and butter.
That’s the conclusion of a new study published in the open-access journal Frontiers in Physiology Mixing e-cigarette flavors has a much worse effect than exposure to just one. The study adds to the mounting evidence of the adverse health effects of e-cigarettes.
E-cigarette use has skyrocketed over the past decade, while traditional cigarette use has declined. In the United States alone, consumers have access to more than 500 brands of e-cigarettes with nearly 8,000 unique flavors.
Vaping exposes the lungs to aroma chemicals when e-cigarette liquids are heated and inhaled. Because flavorings are considered safe, e-cigarettes are often viewed and promoted as a healthier alternative to traditional cigarettes. However, the health effects of inhaling these chemicals are not well understood.
This new study, conducted by researchers at the University of Rochester Medical Center in the United States, aimed to test the hypothesis that vaping these flavored liquids without nicotine is safer than smoking traditional cigarettes.
Previous studies have shown that the flavors used in e-cigarettes induce oxidative stress and inflammatory responses in lung cells. E-cigarette users also have higher levels of markers of oxidative stress in their blood than non-smokers. The new study extends that study to assess the effects of commonly used aromachemicals and nicotine-free e-liquids directly on immune cells, a type of white blood cell called monocytes.
The most toxic were the aroma chemicals cinnamon, vanilla, and butter
Exposure to flavorings from e-cigarettes and e-liquids resulted in increased production of two well-known biomarkers of inflammation and tissue damage caused by oxidative stress. In addition, many of the aromachemicals caused significant cell death, with some aromas being more toxic than others.
dr Thivanka Muthumalage, first author of the study, says that while the flavoring compounds tested may be safe for ingestion, these results show they are not safe for inhalation. “Cinnamon, vanilla, and butter flavor chemicals were the most toxic, but our research showed that the mix of e-liquid flavors caused by far the greatest white blood cell toxicity.”
The lead author Dr. Irfan Rahman hopes this new data will lead to a better understanding of the harmful effects of unflavored e-liquid.
“They’re currently unregulated, and seductive flavor names like Caramel, Cake, Cinnamon Roll and Mystery Mix appeal to young people,” he says. “Our scientific evidence shows that liquid flavors can and should be regulated and that bottles should contain a descriptive list of all ingredients. We urge regulators to take action to protect public health.”
In this study, monocytic blood cells were directly exposed to vaporized liquids. The authors plan to conduct further studies to simulate vaping in vivo by exposing cells to aerosols of vapor liquids in an air-liquid interface system. They are also calling for more long-term human studies to assess the harmful effects of e-cigarettes.
Inflammatory and oxidative reactions induced by exposure to commonly used e-cigarette aroma chemicals and non-nicotine flavored e-liquids