There's a widespread belief that vaping is healthier than smoking cigarettes. But is it really?

Even though electronic cigarettes don't contain tobacco, there's growing evidence suggesting a possible link between vaping and lung cancer. Research into how vaping affects the lungs and a person's cancer risk is still in the early stages, but one thing is abundantly clear: Vaping exposes users to known cancer-causing chemicals.

"It's similar to the situation with cigarettes in the 1930s, when there was a suspicion they caused cancer, but it wasn't until the 1960s that sufficient evidence was available to prove it conclusively," says Dr. Min Kim, a thoracic surgeon at Houston Methodist. "But vaping seems to be following the pattern of what they saw with lung cancer and cigarette smoking nearly a century ago."

The damage could be considerable. By 2022, just 15 years after e-cigarettes and vape pens entered the U.S. market, it was estimated that 7.1% of Texans vape. Moreover, when it comes to Texas high school students, almost 19% have vaped at least once in the past 30 days, slightly higher than the national average.

(Related: Vaping: Learn the Facts, Know the Risks)

What happens when you vape?

When you smoke a traditional cigarette, you inhale the smoke from burning tobacco. With vaping, a device such as an e-cigarette or vape pen heats up a liquid, turning it into a vapor that you inhale.

While inhaling vapor may sound less harmful than smoke, that's not necessarily the case. Vaping coats your lungs with potentially harmful chemicals. These liquid concoctions usually include some mix of nicotine or THC (tetrahydrocannabinol, the chemical in marijuana that causes psychological effects), flavorings and additives.

"There is not one type of vaping," says Dr. Kim. "There are multiple types, and because the Food and Drug Administration (FDA) does not regulate vape products as strictly as traditional cigarettes, you may not always know exactly what you are inhaling into your lungs."

A 2020 study detected more than 500 chemicals in tested vaping cartridges, and most were categorized as carcinogens, or substances that can cause cancer. Some common substances found in vaping products or produced when they are heated up include:

• Nicotine – This highly addictive chemical is found in most vape products.
• Carcinogenic chemicals – Some common compounds found in the vapor, such as formaldehyde, benzene and heavy metals, are known to cause lung cancer and other health risks.
• Diacetyl – When inhaled directly into the lungs, this food additive used to deepen flavor can cause scarring in the air sacs, which then causes the airways to thicken and narrow.
• Ultrafine particles – Vapor contains these tiny particles in higher concentrations than tobacco smoke. When inhaled deep into the lungs, they can become lodged in the trachea and bronchi, worsening respiratory conditions such as asthma.

Carcinogens can cause damage to the DNA inside your cells, which in turn can trigger a chain reaction that turns normal cells into cancerous cells. Simply having contact with a carcinogen doesn't mean you will develop cancer, but longtime or extensive exposure can increase your risk.

The chemicals and particles you inhale while vaping also can cause inflammation in your lungs. Inflammation is a normal response that causes injured tissue to heal by stimulating cells to divide and grow to rebuild tissue. Chronic inflammation increases the chances that cells may mutate and lead to cancer.

Growing evidence links vaping to lung cancer

As you can see, vaping pumps a whole lot of chemicals — many of them known carcinogens — into the lungs. But these products haven't been around long enough for us to say for sure that they cause cancer.

"Does vaping cause harm to the lungs? Yes. Do vaping products contain carcinogens? Yes. Does vaping cause cancer in mice? The studies say yes," Dr. Kim says. "But does vaping cause lung cancer in people? While can't say for sure yet, the evidence is pointing toward yes."

A recent study found that people who both vape and smoke are four times more likely to develop lung cancer than people who just smoke.

How else does vaping affect your lungs?

While we're still studying a potential link between vaping and lung cancer, there are several other lung health risks we know are associated with vaping.

A few of these include:

• E-cigarette or vaping use-associated lung injury (EVALI) – This serious lung condition made news in 2019 when thousands were hospitalized with lung scarring and inflammation after using e-liquid containing vitamin E acetate.
• Bronchiolitis obliterans (BO) – Also known as "popcorn lung," this condition is caused by the food additive diacetyl. When inhaled directly into the lungs, diacetyl causes inflammation and can lead to permanent scarring in the smallest branches of the airways, which makes breathing difficult.
• Lipoid pneumonia – Unlike classic pneumonia, which is caused by infection, lipoid pneumonia develops when fatty acids enter the lungs. The liquids used in vaping products contain oily substances, which, when inhaled, can spark an inflammatory response in the lungs.

There are also questions about whether vaping may trigger lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). Like the link between vaping and lung cancer, these are still being studied.

Get the help you need to quit vaping and/or smoking

It's not unusual to hear people say they started vaping to help them quit smoking.

"But you're just trading one bad habit for another," says Dr. Kim. "Vaping can still cause a lot of damage."

We may not have concrete evidence (yet) that vaping causes lung cancer but quitting vaping does have benefits to your overall lung health and your budget. Nicotine is an incredibly addictive substance, and we know that quitting vaping or smoking is one of the hardest things that a person can do. But it can be done with the right support.

If you are ready to quit, check out these resources at SmokeFree.gov and the Texas Department of State Health Services' YesQuit program, both of which include resources for adults and youth.