• Posted April 11, 2023

Menthol Vapes Could Be Even More Toxic to Lungs

Adding menthol flavoring to electronic cigarettes may damage your lungs more than regular e-cigarettes do, a new study reveals.

The common mint flavoring helps deliver lots more toxic microparticles, compared with e-cigarette pods that don't contain menthol. It's those microparticles that damage lung function, researchers say.

"Beware of additives in the e-cigarettes," said senior researcher Kambez Benam, an associate professor in the division of pulmonary, allergy and critical care medicine at the University of Pittsburgh's School of Medicine.

"If you vape, they can make you inhale more particles into your lungs. Don't assume that since menthol is a substance naturally found in mint plants and added to some food and beverages, it would be fine to inhale," he said.

"Menthol flavoring leads to a significantly higher number of particle counts that one would take into their lungs by vaping them," he said. "E-cigarette aerosols are known to contain many harmful substances, such as nicotine and formaldehyde."

A number of studies have suggested that e-cigarette vapor can cause lung inflammation, oxidative stress, DNA damage and airway hyper-responsiveness that can trigger asthma, Benam said. Vaping these substances can cause lung damage that impairs lung function. Menthol, he added, is such a toxic substance.

To look at the potential danger of menthol, Benam's team developed a "vaping robot" that mimics the temperature, humidity, puff volume and duration of vaping to predict lung damage from e-cigarettes.

The system measures the size and number of aerosolized microparticles and how they act, depending on what's in the liquid. The effects are tested on a so-called "lung-on-chip" device that calculates potential toxicity. What did it find? There were more toxic microparticles emitted with menthol vaping liquid.

An accompanying analysis of patient records for e-cigarette smokers found that menthol vapers took shallower breaths and had poorer lung function compared to non-menthol vapers.

In previous research, Benam's group found that vitamin E acetate, a common additive in e-cigarette liquid that contains THC (the psychoactive ingredient in marijuana), generates tiny toxic particles that lodge in the small airways in the lungs and walls of the trachea and bronchus.

This latest study, which was published online April 11 in the journal Respiratory Research, suggests that menthol additives could be as dangerous as vitamin E acetate, the researchers noted.

Meanwhile, a movement is afoot to ban menthol. In 2022, the U.S. Food and Drug Administration proposed banning menthol in regular cigarettes and denied the marketing of two menthol-flavored e-cigarettes as a way to stop children from starting smoking or vaping.

"It was believed and, in many cases, continues to be believed that the electronic cigarette is a better alternative to the combustible cigarette," said Jennifer Sidi, director of the Center for Tobacco Control at Northwell Health in New Hyde Park, N.Y.

"However, research is being done to disprove that belief. Electronic cigarettes also contain numerous dangerous chemicals, and it is becoming evident that they are not necessarily a healthier option," she said.

Menthol is known to cause a numbing or cooling effect to cigarettes, therefore, making smoking more enjoyable, Sidi explained.

"Adding menthol, however, has allowed smokers to inhale deeper, leading to the inhalation of more carcinogens. This is leading to an increased number of lung cancers, and lung cancers that are being discovered deeper into the lung cavities," she said.

The addition of menthol to e-cigarettes has a similar impact to menthol added to combustible cigarettes, Sidi noted.

"A larger volume of dangerous chemicals are inhaled with the addition of menthol. These chemicals can cause increased damage to the lungs just as they would with the regular cigarette," she said. "This begs the question if there is really any benefit to smoking electronic cigarettes over combustible ones."

Unfortunately, e-cigarettes continue to gain popularity among younger teenagers. "Research is proving that they are not a safer option," Sidi warned, "and the young and impressionable population is the one being targeted to purchase the electronic cigarettes."

More information

For more on menthol, head to the American Lung Association.

SOURCES: Kambez Benam, DPhil, associate professor, division of pulmonary, allergy and critical care medicine, University of Pittsburgh School of Medicine, Penn.; Jennifer Sidi, NP, director, Center for Tobacco Control, Northwell Health, New Hyde Park, N.Y.; Respiratory Research, April 11, 2023, online