Frontline Cancer: 'Vaping' not necessarily healthier than smoking

FRONTLINE CANCER:

Cigarette smoking is responsible for more than 480,000 deaths each year in the United States, according to the Centers for Disease Control and Prevention — that's roughly one in five deaths annually. More than 16 million Americans live with a disease caused by smoking; on average, they will die a decade earlier than non-smokers.

So why does anyone smoke? The addictiveness of nicotine is a big reason. It's hard to stop — and the longer one smokes, the harder it becomes.

E-cigarettes are often touted as a healthier alternative or a transitional way to quitting altogether. In recent years, sales of these battery-powered devices that convert liquid nicotine into a mist inhaled by users have steadily risen — 132 percent from 2012 to 2017, according to the CDC. The biggest users are young people.

But is "vaping" healthier than smoking? That remains a subject of considerable investigation, but one thing is sure: It isn't healthy.

In a study published a couple of years ago, Laura E. Crotty Alexander, MD, an assistant professor at UC San Diego School of Medicine, and co-authors found that e-cigarettes are toxic to human airway cells, that they suppress immune defenses and alter inflammation while, at the same time, boost the virulence of bacterial superbugs.

"E-cigarette vapor is not benign," said Alexander, who is also a staff physician at the Veterans Affairs San Diego Healthcare System. "At high doses, it can directly kill lung cells, which is frightening. We already knew that inhaling heated chemicals, including the e-liquid ingredients nicotine and propylene glycol, couldn't be good for you. This work confirms that inhalation of e-cigarette vapor daily leads to changes in the inflammatory milieu inside the airways."

In a 2015 study led by Wael Al-Delaimy, MD, Ph.D., a professor in the Department of Family Medicine and Public Health at UCSD School of Medicine, researchers found that smokers who used e-cigarettes were 49 percent less likely to decrease cigarette use and 59 percent less likely to quit smoking compared to smokers who never used e-cigarettes.

But two years later, in an effort headed by Shu-Hong Zhu, Ph.D., UCSD School of Medicine professor and director of the Center for Research and Intervention in Tobacco Control, researchers scrutinized national tobacco-use surveys conducted from 2001 to 2015. They found that the smoking cessation rate had increased for the first time in 15 years. In other words, more Americans were quitting smoking.

Zhu attributes the decline in smoking to national tobacco control media campaigns that began airing in 2012. But he also said the popularity of e-cigarettes was a factor — with a caveat. "People who use e-cigarettes are a self-selected group," said Zhu. "They may do better with e-cigarettes because they may already be motivated to quit."

Unlike regular tobacco products, which have been highly regulated for decades, e-cigarettes are broadly and disingenuously promoted to younger consumers with edgy ads and "fun" flavors like cotton candy and pina colada. The approach works.

In a 2017 study, for example, John Pierce, Ph.D., Professor Emeritus of Cancer Prevention at UCSD School of Medicine and Moores Cancer Center, and colleagues found that roughly half of surveyed 12- to 17-year-olds, who had never used tobacco products, were receptive to advertising for products like e-cigarettes, which can be advertised on television and are ubiquitous in manufacturers' social-media campaigns.

The concern, of course, is that vaping can lead to smoking. Indeed, work by Pierce and collaborators has shown that e-cigarette advertising increases the odds of young people who have never smoked tobacco to try cigarettes within a year. A study this year found that non-smoking 12- to 21-year-olds were highly attracted to e-cigarette ads, which then became a gateway to subsequent tobacco use.

There has been less success in smoking cessation. Once people start to smoke, quitting is hard. It's estimated 70 percent of the 46 million Americans who smoke want to quit, but generally it requires multiple attempts to finally be successful. The CDC estimates eight to 10 attempts; others even more. Smokers who try quitting without help fail 95 percent of the time.

Pharmaceutical interventions are routinely prescribed to help people quit, but research at UCSD suggests that despite promising results in clinical trials, smoking cessation drugs alone, such as varenicline, bupropion and nicotine replacement therapy (patch), may not improve the chances of quitting among smokers in general.

"34 percent of people who are trying to quit smoking use pharmaceutical aids, and yet most are not successful," said Pierce. To boost the odds of successfully kicking the tobacco habit, researchers recommend smokers combine drug interventions with behavioral counseling. Many states offer such counseling free over the phone, such as The California Smokers' Helpline (1-800-NO-BUTTS), which is operated by UCSD Moores Cancer Center.

The best way to avoid the harms of smoking is to not start at all. Tobacco prevention efforts clearly work, especially in places like California, which was an early and expansive adopter. In a paper published earlier this year, for example, Pierce and colleagues found that fewer people have taken up the habit, and those who did, quit at a younger age, when their risk of developing lung cancer is lowest. As a result, lung cancer deaths in California are 28 percent lower compared to the rest of the country.

— Scott M. Lippman, MD, is director of UC San Diego Moores Cancer Center. His column on medical advances from the front lines of cancer research and care regularly appears in this publication. You can reach Dr. Lippman at mcc-dir-lippman@ucsd.edu

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