High-nicotine e-cigs up chance teen will become a smoker

It also increases intensity of a teen's future vaping habit


Use of an e-cigarette (top) can increase the risk that teens will begin using conventional cigarettes (bottom). A new study finds that a major factor affecting that risk was how much nicotine a teen had been vaping.


In the United States, last year, more than one high-school student in every 10 used e-cigarettes. While e-cigs do not burn tobacco (as conventional cigarettes do), they usually do provide nicotine. That’s the potentially addictive chemical in tobacco plants that gives smokers a “buzz.” A new study finds that teens who vaped high-nicotine liquids were likely to vape more — and smoke too — six months later.

The findings are not surprising. Earlier studies had shown that teens who vape are about three times more likely than non-vapers to start smoking tobacco. But not all vapers encounter the same levels of nicotine. Vape liquids can vary widely in how much nicotine they contain. What’s more, certain vape techniques and e-cigs can boost how much nicotine come out per puff.

Jessica Barrington-Trimis studies teen smoking and tobacco use at the University of Southern California in Los Angeles. She wanted to explore whether e-cig’s nicotine affected vape habits — or any transition to smoking.

To do this, her team surveyed 181 10th-graders. They came from 10 different Los Angeles area schools. All had vaped within the past month. The teens answered questions about how much and how often they had smoked and vaped in the previous 30 days. They also reported how much nicotine was in their vaping liquid.

The scientists classified those e-liquids on the basis of how much nicotine they had per milliliter (.034 fluid ounce). Some had none. Low-nicotine liquids had no more than 5 milligrams (0.00018 ounce). Medium-nicotine liquids had from 6 to 17 milligrams. High-nicotine e-liquids contained 18 milligrams or more.

Six months later, the researchers surveyed the students again. Now these teens were 11th-graders.

Those who had reported vaping more nicotine in the earlier survey were now more likely to report they also smoked. And the more nicotine they had been vaping before, the more likely they were to now smoke. With each increase in nicotine level — from none to low, from low to medium or from medium to high — teens were now about twice as likely to report frequent smoking. For instance, those who had vaped high-nicotine liquids six months earlier now smoked seven times as many cigarettes per day as did those who had earlier vaped no nicotine.

Nicotine also boosted future vaping frequency and intensity.

Teens who reported vaping more nicotine in the earlier survey were now more likely to vape frequently. Six months out, teens were about 1.5 times as likely to report frequent vaping with each increase in their initial nicotine use. Those who had earlier vaped the most nicotine now vaped almost 2.5 times as often per day as did those who had initially vaped nicotine-free liquids. Moreover, the more frequent vaping also was more intensive. Teens now took more puffs each time they vaped.

Barrington-Trimis and her team published their findings in the December JAMA Pediatrics.

Richard Miech is a sociologist, someone who studies human behavior. His work at the University of Michigan in Ann Arbor focuses on adolescent drug use. (And yes, nicotine is a drug.) “This study is important,” he says. “It begins to chip away at the ‘black box’ that links e-cigarette use with later use of regular cigarettes.”

“Ideally,” he says, “studies like this will encourage government agencies to develop policies that will make it very difficult for youth to obtain e-liquids with nicotine.”

Teens are especially prone to nicotine addiction. But that is not the only concern. Nicotine has been linked to many health risks in teens. These include problems with learning, with attention and with impulse control. In 2016, the U.S. Surgeon General released a report on e-cigarettes. It concluded that nicotine in any form is not safe for young children or teens. 

Aimee Cunningham is the biomedical writer at Science News. She has a master’s degree in science journalism from New York University.

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