E-cigarettes (e-cigs), vapes, and hookah pens are some of the terms to describe noncombustible tobacco products called electronic nicotine delivery systems (ENDS). Compared to conventional cigarettes, these products use a liquid formal that may or may not contain nicotine and flavorings. They come in different forms such as cigars, pipes, and tanks. It could even take the form of a conventional cigarette.
Since the introduction of e-cigarettes about a decade ago, the use of these products has skyrocketed, especially among young individuals. Even though the products are prohibited among minors, the Food and Drug Administration (FDA) stated that about 3.62 million middle and high school students use e-cigarettes last 2018.
A 2013-2014 survey stated that 81% of current youth e-cigarette users consider the availability of appealing flavors as their primary reason for using the product. The different liquid flavors — ranging from sweet and fruity to menthol — appeal significantly to the youth since, according to them, it makes the product “seem harmless.”
Some advocates say that the flavors in the liquids are essential to help adults in switching from conventional cigarettes — which they perceived as more harmful than e-cigarettes since there are less cancer-causing chemicals.
However, those who are against the selling of flavored e-cigarette liquids argue that it should be banned due to its increased appeal to the young adults and it masks the harmfulness and addictive property of these products.
Although some studies say that e-cigarettes are less harmful than conventional ones, its effect on a person’s vascular health is still unclear.
Recently, a study conducted by researchers from Stanford University School of Medicine and published in the Journal of the American College of Cardiology has shown evidence of the harmful effects of these products on the human cells.
The study discovered that e-cigarette flavors could damage the cells that line the interior of our blood vessels. These cells, called the endothelial cells, were generated in the laboratory from human induced pluripotent stem cells (Human iPS cells) and were exposed to the e-liquids and to blood collected from e-cigarette users shortly after vaping.
The findings showed that the cells became less viable and exhibited significantly increased levels of molecules which are associated with DNA damage and cell death. They were also dysfunctional in forming new vascular tubes and in migrating and participating in wound healing.
Researchers said that the damages were noted even in the absence of nicotine and varied among flavors. They tested six favorite flavors like fruit, tobacco, sweet tobacco with caramel and vanilla, sweet butterscotch, cinnamon, and menthol. And among these juices, they found out that cinnamon- and menthol-flavored liquids were the most potent in causing the most damage in the endothelial cells even without the presence of nicotine.
Aside from decreasing the viability of the cells, exposure to the flavored liquids also increased the relative levels of reactive oxygen species (ROS): which are substances that could damage the DNA and cause cell death.
Since the study only used six different flavors of e-cigarette liquids, there are still thousands of juices available in the market that are yet to be tested to determine their respective effects on the human cells. Researchers are still uncertain about how these juices behave with regards to the human cells and how it causes the damage highlighted previously.
Doctors from the University of Massachusetts Medical School stated in a commentary published in the same journal that the experiment must be tested in animal models – and not just in cultured cells – to have a better understanding of the matter.
According to Stanford University, this study was the first to use endothelial cells derived from iPS cells to directly examine the effect of liquids from e-cigarettes with and without nicotine on their viability and function. Their results added to the growing evidence that e-cigarettes may pose harm to our health.
Joseph Wu, MD, Ph.D., who is the director of the Stanford Cardiovascular Institute and professor of cardiovascular medicine and radiology, told CNN that “this study clearly shows that e-cigarettes are not a safe alternative to traditional cigarettes.”
Moreover, Dr. Lawrence Phillips who is an assistant professor of medicine and director of outpatient cardiology at NYU Langone Health also said that “when we compare traditional cigarettes to e-cigarettes, we’re not comparing apples to apples. What we’re finding is that both are having increased risk.”