Chemical flavor additives used in e-cigarettes and related tobacco products may harm vascular endothelial cells that regulate blood vessels, according to findings published in Arteriosclerosis, Thrombosis and Vascular Biology.
“Use of alternative tobacco products including electronic cigarettes is rapidly rising,” Jessica L. Fetterman, PhD, from Boston University School of Medicine, and colleagues wrote. “The wide variety of flavored tobacco products available is of great appeal to smokers and youth. The flavorings added to tobacco products have been deemed safe for ingestion, but the cardiovascular health effects are unknown.”
Fetterman and colleagues investigated how nine common chemical flavorings for e-cigarettes affect vascular endothelial cell function. The nine flavors tested included menthol (mint), acetylpyridine (burnt flavor), vanillin (vanilla), cinnamaldehyde (cinnamon), eugenol (clove), diacetyl (butter), dimethylpyrazine (strawberry), isoamyl acetate (banana) and eucalyptol (spicy cooling).
The researchers collected aortic endothelial cells from nine nonsmokers, as well as six nonmenthol and six menthol cigarette smokers. They incubated the cells with the flavoring compounds for 90 minutes, then measured cell death, reactive oxygen species production, expression of the proinflammatory marker interleukin-6 and nitric oxide production.
Smokers showed impaired A23187-stimulated nitric oxide production, compared with nonsmokers. When nonsmokers’ cells were exposed to menthol or clove flavoring, a similar reduction in nitric oxide production was observed.
At the highest levels, all flavorings caused the endothelial cells to die. Lower levels of cinnamon, clove, strawberry, banana and spicy cooling flavor also caused cell death. Vanilla and clove flavorings caused oxidative stress of the endothelial cells.
Menthol, vanilla, cinnamon and burnt flavors increased interleukin-6 and reduced nitric oxide.
When heated, vanilla and clove flavor impaired nitric oxide production, but menthol did not.
“Increased inflammation and a loss of nitric oxide are some of the first changes to occur leading up to cardiovascular disease and events like heart attacks and stroke, so they are considered early predictors of heart disease,” Fetterman said in a press release. “Our findings suggest that these flavoring additives may have serious health consequences,” particularly for the lung and cardiovascular systems. – by Alaina Tedesco
The authors report no relevant financial disclosures.