What to know about vaping and cancer

Cigarette smoking is the leading cause of preventable death. In fact, smoking causes more than 7 million deaths worldwide each year.

Vaping has been claimed to be a safer alternative to smoking cigarettes, and even as a method to help quit. But is vaping really any safer?

A brief history of vaping

Vaping is the use of electronic cigarettes (or e-cigarettes) and similar handheld devices that heat and vaporize liquids so that they can be breathed into the lungs. In addition to tobacco, e-cigarettes can also be used to smoke marijuana.

Vaping liquids typically contain nicotine (the main addictive substance found in cigarettes), flavor enhancers, and chemicals like propylene glycol (a chemical that is also used in antifreeze). The exact combination of ingredients varies according to brand and flavor, although package labels aren’t always accurate. In fact, some products that claim to be nicotine-free have been found to contain the substance.

“Until we actually have U.S. Food and Drug Administration (FDA)-approved studies, there really is no consistent way for consumers to know exactly what they’re getting,” says Susan Garwood, MD, a pulmonary critical care physician at TriStar Centennial Medical Center in Nashville. That lack of transparency, along with concern over the safety of chemical ingredients, lead to demands for the FDA to regulate vaping products in 2016. In response, the agency announced that vape companies would have to start submitting their products for approval by August 2016.

Two years later in August 2018, the agency announced that it was placing restrictions on companies that make or sell vape products packaged to resemble treats that appeal to children, like juice boxes and candies. Advertising tobacco products in this way violates the Federal Food, Drug, and Cosmetic Act.

Then, in January 2020, the FDA banned marketing and distributing prefilled, flavored e-cigarette products aside from menthol and tobacco. Refillable and cheap disposable vape cartridges (called pods) were not prohibited, however, creating an opportunity for use of flavored e-liquids (also called vape juice).

But in October 2021, the FDA for the first time permitted marketing of three e-cigarette products to help adult smokers wean themselves off tobacco. In studies, smokers successfully used certain Vuse Solo devices to reduce or quit traditional cigarettes, according to an agency press announcement.

The FDA didn’t give approval for these items—which would have signified an endorsement of tobacco use—but rather an authorization, which only allowed specific products to be marketed for a specific use. In fact, the agency was careful to note that tobacco products are both harmful and addictive, and that Vuse will be carefully monitored to ensure it follows FDA marketing requirements. If it doesn’t, the authorization can be taken back.

While there is still much to be learned about the safety of electronic cigarettes, here's what we do know.

What’s in e-cigarettes?

Here are some common ingredients in e-cigarettes and how they affect your body.

Nicotine: The majority of vaping liquids contain nicotine. More research on the long-term effects of e-cigarettes is needed, but we already know the nicotine content in vaping liquids can pose health risks. Nicotine increases how fast your heart beats, is highly addictive, and is associated with problems with brain development including issues with memory and paying attention among teenagers.

Parents must keep vaping devices out of reach of children, says Dr. Garwood, since ingesting even a few drops of the liquid can be dangerous and even deadly. In 2016, Congress passed legislation requiring child-resistant packaging for vaping liquids, but many cartridges can still be opened by curious children. Between January 2012 and April 2017, more than 8,200 cases of exposure to liquid nicotine in children under age 6 were reported, according to a study published in the journal Pediatrics in 2018.

Vaping is also unsafe during pregnancy. “Somehow I think society sees e-cigarettes as more acceptable for pregnant women to use. That is not the case," notes Garwood. Nicotine can cause pregnancy complications including low birth weight, and damage to the brain and lungs.

Flavor enhancers: From cinnamon roll to pink lemonade, there are many flavor possibilities of vape juice. In addition to being potential carcinogens (substances that cause cancer), these liquids present a higher risk of damage to the lungs when they are breathed in, Garwood says.

Chemicals: E-cigarettes often contain an array of chemicals that become toxic when heated. Propylene glycol, for instance, turns into formaldehyde at high temperatures. Formaldehyde—a naturally occurring chemical often found in building materials and household cleaners—is a known cancer-causing substance that can cause asthma and affect how well your lungs work.

Research published in the journal Scientific Reports in May 2018 suggests e-cigarettes contain more formaldehyde than previously believed. The amount users inhale varies according to brand, flavor, and the size and frequency of puffs, but some research suggests it’s possible to get more formaldehyde from e-cigarettes than from cigarette smoking.

“It depends on how long it takes you to ingest the 3 milliliters of liquid," says Garwood. She explains that if you're puffing through a whole cartridge in a day, you may get substantially more formaldehyde than from a pack of cigarettes. It depends in large part on the e-cigarette battery voltage.

Who is using e-cigarettes?

Electronic cigarettes have become the most commonly used tobacco products among teens, despite age restrictions that state a person needs to be 18 years old to purchase these devices. In 2021, a report from the Centers for Disease Control and Prevention (CDC) found that about 2 million middle and high school students in the United States reported using e-cigarettes within the previous 30 days, including 2.8 percent of middle school students and 11.3 percent of high schoolers.

As for adults, about 4.5 percent used e-cigarettes in 2019. More than 76 percent of them were current or former regular cigarette smokers. The rest—about 24 percent—had never been traditional cigarette smokers.

Can vaping actually help you quit smoking?

Though the FDA authorized the use of specific e-cigarette devices for use as quit aids in October 2021, vaping is not officially approved by the agency or supported by the American Lung Association (ALA) as a safe way to taper off traditional cigarette use. In fact, the ALA did not support the FDA’s decision on Vuse Solo products. The U.S. Preventive Services Task Force (USPSTF) also says there isn't enough evidence to recommend e-cigarettes as part of a healthy quit plan and that more research is needed.

While some studies support the use of e-cigrettes as quit aids—including the research used by the FDA to justify their Vuse approval—many other studies are not as supportive. For example, a study that included 2,800 smokers and was published in the journal PLOS One in 2020, found no evidence that vaping is a helpful quit aid. Researchers found that one to two years after quitting, those who used e-cigarettes had similar success rates of staying quit as those who used approved quit aids or nothing at all.

Since e-cigarettes are largely not authorized for smoking cessation, there aren’t clear strategies in place for decreasing and finally stopping the use of these devices. The amount of nicotine users inhale isn’t typically controlled, and it may not decrease over time. Instead, it varies according to the size and frequency of puffs. In fact, “people may actually be getting more nicotine because of the way they use the devices,” Garwood says.

Is it safe to vape?

More studies are needed to learn the lasting effects of vaping on your health. That said, a growing amount of research suggests that e-cigarettes are linked to multiple illnesses, including breathing issues like asthma and chronic obstructive pulmonary disease (COPD, a condition that damages and scars the lungs and does not have a cure).

For example, one 2020 study in the American Journal of Preventive Medicine found that people who used only e-cigarettes had a 75 percent higher risk of developing COPD compared to those who never smoked. Daily users also had a 73 percent higher chance of asthma (inflammation of the lungs that causes breathing problems and does not have a cure), compared to nonsmokers. Current and former smokers of traditional tobacco had higher odds of COPD, as well.

An increased cancer risk is possible, as well, but has not been confirmed. In general, there are fewer harmful chemicals in e-cigarettes compared to traditional cigarettes, although the amount of exposure varies with brand and how users smoke them. Early studies suggest some brands contain a number of cancer-causing chemicals, in addition to formaldehyde.

“If you had an option not to be exposed to carcinogens at all, wouldn’t you choose that?” asks Garwood.

In 2019 and early 2020, more than 2,800 emergency room visits and about 60 deaths were associated with a condition known as e-cigarette (or vaping) product use-associated lung injury (EVALI), a breathing condition associated with starting to use e-cigarettes. Officials linked the deaths to e-cigarettes that contain tetrahydrocannabinol (THC, a substance found in marijuana, or weed), and an additive called vitamin E acetate (an oily chemical used for either thickening or diluting vaping fluid). Enforcement and awareness helped to decrease the number of cases, but the problem pointed to the need for strong, continuing regulation.

The important point is that many e-cigarettes are probably ineffective ways to help you quit smoking, and are likely to be harmful to your health. If you smoke them already, ask your healthcare provider about how to quit, and how your insurance may help cover the costs. If you don’t already smoke them, it's better not to start.