Popular E-Cig Flavors May be Harmful when Inhaled
Researchers have discovered that e-cigarette liquids sweetened with popular flavorings may damage cells in the blood vessels and heart when inhaled even when they don’t contain nicotine, according to a small sample study performed in lab tests in which scientists exposed endothelial cells in arteries and veins and inside the heart to a variety of flavorings. The team tested the effects of varying concentrations of nine sweeteners, including banana, butter, cinnamon, clove, eucalyptus, mint, strawberry, vanilla and “burnt,” which is equitable to a burnt popcorn flavor.
At high concentrations, all nine flavorings damaged cells, according to the tests. Five of the sweeteners – vanilla, mint, cinnamon, clove, and burnt – impaired production of nitric oxide. “The loss of nitric oxide is important because it has been associated with heart disease outcomes like heart attacks and strokes,” said lead study author Jessica Fetterman of Boston University School of Medicine. “It is one of the first changes we observe in the blood vessels in the progression to heart disease and serves as an early indicator of toxicity. Our study suggests that the flavoring additives, on their own in the absence of the other combustion products or components, cause cardiovascular injury.”
Even when e-liquids don’t contain any nicotine, the lungs are exposed to chemicals when the vapors are inhaled. Previous research has also indicated inhaling vapor from these chemicals may damage the lungs, much like traditional cigarettes.
The cells from nine nonsmokers and 12 smokers of traditional cigarettes were tested in addition to commercially purchased endothelial cells from human hearts. The researchers found that even before they were exposed to chemicals, tobacco smokers’ cells already had a reduced ability to produce nitric oxide. Nonsmokers’ cells had impaired nitric oxide production after they were exposed to the flavors.
“We already know that tobacco smoke affects endothelial cells, leading to cardiovascular diseases,” said Irfan Rahman, a researcher at the University of Rochester Medical Center. The current results suggest that vaping isn’t any safer than smoking traditional cigarettes.
Consumers may also have a hard time determining the amounts of any chemicals in the e-cigarettes they purchase, which makes it nearly impossible to avoid ingesting higher doses. “It is currently difficult for the consumer to control exposure to flavor chemicals,” said Prue Talbot, a molecular biology researcher at the University of California Riverside. “Manufacturers do not list the flavor chemicals and their concentrations on products, so consumers do not have a simple way to identify products they might choose not to use if they had more information on their contents.” It is unclear whether this will be a requirement in the future.
The potential hazards associated with e-cigarettes are still controversial and a full picture is yet to be made available because they have only recently gained mainstream traction. Maciej Goniewicz of Roswell Park Comprehensive Cancer Center in Buffalo, New York, said, “Combustible tobacco products already release many toxicants that cause cardiovascular diseases, but the situation may be different for e-cigarettes that do not burn tobacco. I think it is important for future studies to compare the cumulative toxicity of the inhaled e-cigarette aerosol with and without flavored chemicals.”