There is ever-increasing evidence that the harm from electronic cigarettes far exceeds the benefits of their use as an aid to stop smoking nicotine cigarettes.

The latest reported health effects are to the delicate tissues of the vascular system from the use of flavorings in electronic cigarettes. A new study looked at the impacts of nine different flavors on vascular endothelial cell function.

The flavors tested were vanillin (vanilla), menthol (mint), cinnamaldehyde (cinnamon), eugenol (clove), dimethylpyrazine (strawberry), diacetyl (butter), isoamyl acetate (banana), eucalyptol (spicy cooling) and acetylpyrazine (burnt flavor).

Cell death was only evident at very high concentrations, and such concentrations are not likely in real-world consumptions. Lower concentrations of vanillin, menthol, cinnamaldehyde, eugenol and acetylpyridine induced both inflammation and signs of endothelial dysfunction. These flavorings are used in e-cigarettes, hookah, small cigars and cigarillos.

"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," reported lead study author Dr. Jessica L. Fetterman, assistant professor of medicine at Boston University School of Medicine in Massachusetts. "Our findings suggest that these flavoring additives may have serious health consequences."

The negative health consequences of several popular e-cigarette flavors have long been recognized.

An irreversible lung disease, bronchiolitis obliterans, was found to be associated with the inhalation of diacetyl and was first identified in workers at a microwave popcorn company. Cherry flavoring was also found to be 1,000 times higher in e-cigarette products compared to a dose studied in an occupational hazard investigation that was shown to produce irritation to the respiratory pathways.

A major concern related to flavorings in electronic cigarettes and other products is that they are marketed toward younger smokers and adolescents. High school and middle school students are using these flavored e-cigarette products.

The majority of adults using e-cigarettes are those who formerly used burning cigarettes. The use by youth, however, is rising dramatically and rapidly, with 37 percent of high school students reporting having smoking an e-cigarette in 2015.

More recent reports based on data analysis in the 2011-2017 National Youth Tobacco Surveys from the Centers for Disease Control and the Food and Drug Administration found that in 2017, electronic cigarettes were the most commonly used tobacco product among high school students at a rate of 11.7 percent and middle school students at a rate of 3.3 percent.

"Our work and prior research have provided evidence that flavorings induce toxicity in the lung and cardiovascular systems. Flavorings are also a driver of youth tobacco use and sustained tobacco use among smokers," Fetterman said.

"We still don’t know what concentrations of the flavorings make it inside the body," Fetterman further stated.

This is a concern for youth who are still growing and developing. The American Heart Association is calling for strong new regulations to prevent access, sales and marketing of e-cigarettes to youth, and for more research into the health impacts of the products.