The science of vaping

Every day brings new headlines about e-cigarettes, from reports of seizures to the first death linked to lung problems after vaping. Between 2011 and 2015, e-cigarette use surged 900% among middle- and high-school students in the United States, according to the Centers for Disease Control and Prevention.

“In some ways, e-cigarettes snuck up on everybody, especially the explosion in youth use,” says Jason Robinson, Ph.D., associate professor of Behavioral Science.

In November 2018, the Food and Drug Administration took steps to limit youth access to e-cigarettes and in December 2018, the U. S. surgeon general released an advisory on the e-cigarette “epidemic” among youth.

Long-term risk unknown

While most experts, as well as some e-cigarette manufacturers, agree that youth e-cigarette use is bad, e-cigarettes are still marketed as a safer option than traditional cigarettes for current adult smokers.

The website for one popular e-cigarette brand claims their product is a “satisfying alternative to cigarettes” with a mission to “eliminate cigarettes.”

Although e-cigarette vapor contains less toxicants than tobacco cigarette smoke, the long-term risks of e-cigarette use are still unknown. Scientific evidence hasn’t consistently shown that current adult smokers will safely and successfully quit traditional cigarettes in favor of e-cigarettes, either.

“A lot of people become dual users, meaning they use both products, which is not actually healthier for you. In fact, it’s probably making your nicotine dependence worse,” Robinson says. “Smoking is the single most preventable cause of cancer, despite the fact that we’ve had about 60 years of success reducing the smoking rate in the U.S. One of the big fears we have is that the number of people who are smoking in the country may start creeping back up.”

The research race

Studying the impact of e-cigarettes on current smokers’ behavior is challenging on several fronts. One of the biggest issues is that scientific research struggles to keep pace with the fast-growing e-cigarette industry. In 2009, the Tobacco Control Act gave the FDA authority to regulate tobacco products, including levels of nicotine, the addictive component of cigarettes. While reducing nicotine content might seem like an easy choice to reduce the appeal of smoking, if it caused people to compensate by smoking more or inhaling more deeply to get the same amount of nicotine, it could actually increase the amount of dangerous toxicants they inhale. In 2013, MD Anderson was part of a multisite study to find out if the nicotine levels in cigarettes could be reduced safely.

“We got all the way down to a really low dose, which was about 3% of the nicotine in a commercial cigarette, and current smokers were able to tolerate it and reduce their smoking without compensating,” Robinson says.

By the time the results were published and confirmed by a follow-up study in 2018, the e-cigarette epidemic was well underway. As the landscape changed, Robinson and Paul Cinciripini, Ph.D., chair of Behavioral Science, developed a study to evaluate smokers’ behavior when given access to both very low-content nicotine cigarettes and to e-cigarettes.

They designed the study using a popular e-cigarette product at the time. The product in their study is now considered outdated, so another arm of the study using today’s No. 1-selling e-cigarette brand is in the works.

“This has really been happening over the last few years, and with the nature of research, it’s so hard for us to keep up with it,” Robinson says. “It’s also fascinating because we have a chance to make a mark by providing the FDA with the evidence they need to enact a regulation about limiting the amount of nicotine in tobacco products. In that sense, it’s really exciting.”

Regulatory restrictions

The second challenge to studying e-cigarettes as a smoking-cessation aid in the U.S. is that e-cigarettes are not considered therapeutic drugs.

“In order for the FDA to consider whether e-cigs can be evaluated as a therapeutic product, a manufacturer would have to submit an Investigational New Drug (IND) application to the FDA,” Robinson says. “Without the IND, researchers cannot submit proposals to study e-cigarettes as a potential therapeutic or cessation tool.”

In early 2019, the FDA released a draft guidance to address this issue. Until the recommendations are finalized, researchers are limited to studying whether or not current smokers can safely “switch” to e-cigarettes, rather than whether or not e-cigarettes can help adults quit smoking.

“The challenge for us in keeping up with the industry is our ability to evaluate both the safety of these new products and their effectiveness as a cessation device at the same time,” Cinciripini says. “Under current regulatory guidelines, we can’t study cessation – that has been left to researchers in other countries. One interesting study from the UK showed e-cigarettes may have potential as a cessation tool, but smokers who quit with e-cigarettes continued to use them a year later which suggests continued nicotine dependence. At present we don’t know their long-term risks and benefits.”