A study posted in the journal 'Arteriosclerosis, Thrombosis, and Vascular Biology', was the end result of a number of experiments carried out by a team from Boston University. In this study, the scientists claim that certain flavorings added to e-cigarettes can cause an impairment in the production of nitric oxide in endothelial cells, as well as having a harmful effect on certain cells that are in line with coronary blood vessels.
In particular, the team pointed out 9 flavorings which are the worst offenders:
• menthol (mint)
• vanillin (vanilla)
• diacetyl (butter)
• eucalyptol (spicy cooling)
• acetylpyridine (burnt flavor)
• dimethylpyrazine (strawberry)
• eugenol (cloves)
• isoamyl acetate (banana)
• cinnamaldehyde (cinnamon)
According to the study's lead author, Jessica L. Fetterman, Ph.D., "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. Our findings suggest that these flavoring additives may have serious health consequences."
To carry out their earliest experiments, the team began by extracting some endothelial cells from two groups of tobacco smokers - regular cigarette smokers and menthol cigarette smokers. They then compared the results to those taken from non-smokers, some of whose cells had been exposed to common e-cigarette flavorings. They discovered the cells of both smoking groups were less able to produce nitric acid, which is essential for blood vessels to dilate.