Two chemicals widely used to flavor e-cigarettes could be harming users’ lungs, according to a new study by Harvard T.H. Chan School of Public Health.
The study is the first to look at the impact of the flavoring chemicals – used to make more than 90 percent of e-cigarettes – on the “cilia” that line the lungs. Given the recently labeled “epidemic” of e-cigarette use among school-aged children, the results were less than encouraging.
Questions about the Dangers of E-Cig Flavors Finally Answered
The respiratory system has built-in lines of defense against dust, dirt, and other debris, the first and most important of which are cilia. These microscopic hairs are found along air passages in the respiratory tract and move in a rhythmic, sweeping motion to filter debris up and out of the airways, allowing us to breathe easily.
But when you inhale harmful substances, cilia stop functioning properly, leading to health problems like bronchitis. Until now, flavoring chemicals have played a largely unknown role.
“Although chemicals used to flavor e-cigs are frequently used, little has been known about the mechanism of how they impact health,” said Quan Lu, associate professor of environmental genetics and pathophysiology at Harvard and co-author of the study alongside assistant professor Joseph Allen.
Scientific studies on the health effects of e-cigarette flavors “have not kept pace” with the increasing popularity of vaping, according to Harvard’s report. Flavoring chemicals have only been linked to occupational diseases. But a few years ago, these chemicals caught Harvard’s attention as a serious hazard for e-cigarette users, and in this study, were investigated deeper.
The 2 chemicals are called diacetyl and 2,3-pentanedione – the former, commonly used as a flavoring agent in foods like butter popcorn, candy, and baked goods and considered safe as a food ingredient. Yet diacetyl has been linked with bronchiolitis obliterans, a debilitating lung disease dubbed “popcorn lung” when it first appeared in workers who processed popcorn. Since the link to popcorn lung was reported, 2,3-pentanedione was often used as a substitute.
But after simulating a human airway and exposing cilia to the 2 chemicals for 24 hours, Harvard researchers found that both could impair the production and function of cilia.
What Does This Mean for (Increasingly Young) Users?
Millions of people use e-cigarettes, but an alarming (and growing) portion of them are teens. Research shows that e-cigarette use skyrocketed 78 percent among high schoolers and nearly 50 percent among middle schoolers between 2017 and 2018, constituting the “largest year-to-year increase in substance use ever recorded” in the U.S. in that age group, according to the American Lung Association (ALA).
The government responded last year with plans to restrict e-cigarette sales and by declaring youth e-cigarette use an epidemic. Yet in a “State of Tobacco Control” report released last month, the ALA said the Food and Drug Administration (FDA) has done too little to protect teens from what has quickly become a public health crisis – the solutions to which are still proposals in the making. The government shut down has done even less to help the situation by limiting the FDA resources available to regulate e-cigarettes.
For workers, there are standards on safe limits of exposure to flavoring chemicals. But Harvard researchers found that even low levels of exposure to the chemicals can impair lung function, suggesting the standards aren’t sufficient. For e-cigarette users, there are none at all.
“E-cigarette users are heating and inhaling flavoring chemicals that were never tested for inhalation safety,” said Allen.
“Although some e-cig manufacturers are stating that they do not use diacetyl or 2,3-pentandione, it begs an important question: what chemicals, then, are they using for flavoring?” he continued. “Further, workers receive warnings about the dangers of inhaling flavoring chemicals. Why aren’t e-cig users receiving the same warnings?”
It all comes back to e-cigarette makers’ notorious effort to hook young users. These companies have used social media, candy-like flavor names, and other intentional marketing tactics – many of them uncovered last year in a surprise inspection of leading manufacturer Juul – to make kids believe vaping is “cool” at a young enough age that they will struggle to quit for life.
Experts believe the only solution to youth vaping is to ban all flavored products outright. As to that, the FDA has no plans yet.