"The measures that we looked at for our study are some of the very first changes that we see in the development of heart disease", Jessica Fetterman, the lead author on the study, said in a phone call with The Outline. Research has shown that smokers of menthol cigarettes receive a "physiologically relevant" dose of the flavor in their bloodstream when they light up, indicating that damage to endothelial cells could be occurring, Fetterman explained.
The e-cigarette flavorings were tested on endothelial cells, which line the blood vessels and inside of the heart. "Heating or combustion of the flavoring compounds likely alters the compounds, making them more or less toxic". In May, a study presented at the American Thoracic Society's annual meeting found that cinnamaldehyde (cinnamon) flavoring appears to inhibit a key mechanism of the lungs' antibacterial defense mechanism.
Longtime tobacco researcher and physician Dr. Neal L. Benowitz, who was not involved in the study, said the new findings are an important contribution to existing research but aren't "really ready for translation to clinical practice or regulatory standards".
To investigate the effects of the flavored liquids used in electronic cigarettes, researchers assessed nine popular flavors. "Our findings suggest that these flavoring additives may have serious health consequences".
Recent statistics from the Centers for Disease Control and Prevention show tobacco use has gone down among youth.
A pilot study published and funded by the National Institutes of Health, found that e-cigarettes could significantly reduce harm and the risks of cancer and other diseases to smokers.
The dangers of combustible cigarettes on the cardiovascular system has been known for decades, however e-cigarettes have only been around since the early 2000s. "That's something we don't really know", Fetterman said. It represented more than half of all e-cigarette sales in the U.S.as of March, according to Nielsen data.
E-cigarettes are widely believed to be healthier than traditional cigarettes, but building evidence suggests the products carry their own risks.
Fetterman hopes her research motivates public officials to follow the lead of San Francisco and outlaw tobacco and nicotine products with flavorings.
It states: "Although nicotine is addictive, it's the combustion of tobacco in conventional cigarettes and the by-products formed, that cause the most harm associated with smoking". However, this quick adoption (partially brought on by insidious marketing by Big Tobacco) makes it hard to get a firm, clear grasp on the long term effects of these products in a timely manner. Although numerous flavorings used to produce the flavors have been determined to be safe in food products, the long-term safety for inhalation into the lungs is not known.