A recent University of Michigan study revealed that e-cigarette use may act as a bridge to traditional tobacco use. The study showed that teens who vape are four times more likely to start smoking traditional tobacco cigarettes within a year of smoking e-cigs. Scientists attribute the gateway effect to “desensitization” to the dangers of tobacco smoking ostensibly because e-cigarettes have a relatively low smoke output and are touted as being relatively “safe” in comparison to traditional cigarettes. The study results support that restriction of e-cigarette use in minors is critical to prevent long-term smoking behaviors.

Contradicting the study are scientists from a previously released College of London study that showed e-cigarettes are safer than traditional smoking. These and other U.K. scientists denounce the University of Michigan results as either misleading or “exaggerated” to support a U.S. “moral crusade” against e-cigarettes. In reality, it is just a matter of understanding statistics and study results.

The University of Michigan study is not wrong; it just doesn’t distinguish between those who would never try to smoke (e-cigs or otherwise), and those who will. Those who will never try cigarettes may never try e-cigarettes. However, the Michigan study shows that those who will, and do try e-cigarettes are four times more likely to smoke regular cigarettes later—and that throws hot water on the belief that e-cigarettes are benign.

The UK scientists continued their criticism and the attempt to bolster their “e-cigarettes are safe” study with mention of the 22,000 people per year who quit smoking regular tobacco cigarettes by using e-cigarettes. Unfortunately, that figure is not very compelling—it equates to only a fraction of a percent (0.06%) of U.S. smokers, which, as of 2015, was still 36.5 million adults. Data points from the CDC tend to support the Michigan study:

• Smoking harms nearly every organ of the body.

• 1% of all adults (36.5 million people): 16.7% of males, 13.6% of females were current cigarette smokers in 2015.

• Thousands of young people start smoking cigarettes every day

• Use of multiple tobacco products increases the risk of nicotine dependence and long-term tobacco use.

E-cigarettes are included in the list of “multiple tobacco products,” and are now regulated in the U.S. in the same way as other “tobacco.” In fact, according to the CDC figures, the use of e-cigarettes is on such a rise that it almost matches that of regular tobacco use. Refer to the CDC table below to see how fast e-cigarettes have risen to the levels of traditional cigarette use in students.

Source: CDC. Tobacco Use Among High School Students in 2015

The main author of the College of London study, Professor Robert West, was reported to have said that “virtually all users of e-cigarettes were past smokers, not the other way around.” The CDC numbers contradict this statement. Instead it shows young people are now starting tobacco use with e-cigarettes, e.g., see above where 5.3% of middle schoolers have vaped. This data seems to support the University of Michigan finding that, “Vaping as a risk factor for future smoking is a strong, scientifically-based rationale for restricting youth access to e-cigarettes.”

It is unclear why the U.K. scientists from the previous study are adamant that e-cigarettes are healthy when the use of this type of tobacco delivery system is still in its infant stage. It is also unclear why the U.K. made such an outcry when their study compared the safety to traditional cigarettes (apples) rather than determining if e-cigarettes acted as a gateway to other tobacco use (oranges). If they haven’t been misquoted, one might ask if they have a crusade to preserve e-cigarette use for the sake of their “study” reputation rather than taking a moment to recognize potential dangers brought forth in the more current Michigan study. The only clear information at this point is that dangers of e-cigarette use continue to be revealed over time.

In addition to the potential danger as a gateway to long term tobacco use, e-cigarettes also pose a danger from inhaling diacetyl and other chemicals known to be in e-cigarette liquids. There is also the growing incidence of explosions attributed to product delivery system, i.e., electronic vaporizers and the lithium batteries that enable nicotine inhalation. The explosion incidents alone are responsible for serious chemical and heat burns that require months of hospitalization as well as skin grafts, bone grafts, and ongoing medical care for physical damage and psychological trauma.