The compounds that give flavor to vaping liquids could have harmful effects on respiratory health.
This is particularly true for molecules that provide cinnamon or citrus flavors to these products, reveals a study published in the
American Journal of Physiology - Lung Cellular and Molecular Physiology by a team from the Faculty of Medicine at Université Laval and the Research Center of the Institut universitaire de cardiologie et de pneumologie de Québec-Université Laval.
Illustration image Pixabay
"The molecules used to flavor vaping liquids are the same ones used in food or perfumes," explains the study's lead researcher,
Mathieu Morissette. "There are hundreds of these molecules, and some can cause significant inflammatory skin reactions. We wanted to document the potential effects of these molecules on the lungs."
His team studied four molecules, either alone or in combination, commonly used in flavor blends added to vaping liquids. "We documented their effects on cells called dendritic cells, which act as sentinels because they are among the first to react to the presence of inflammatory or pathogenic molecules in the body. Moreover, these cells 'decide' whether or not to mobilize other immune system cells," explains Professor Morissette.
Under normal conditions, dendritic cells remain in an immature state in the respiratory mucosa. They mature when they detect the presence of potentially harmful molecules in the body. This activation is the first step in a cascade of immune reactions that can lead to sensitization and lung inflammation. This can result in a form of occupational asthma, which has been documented, among others, in people who work with crab, paint, or pine.
Tests conducted in vitro on mouse dendritic cells and in vivo on mice show that cinnamaldehyde (cinnamon flavor) and citral (lemon or lime flavor) can activate dendritic cells. "We should not conclude that other flavors are safe for human lungs," emphasizes Professor Morissette. "Responses to these molecules vary greatly from person to person. Our study aimed to provide proof of concept that certain flavor molecules can trigger a response from lung dendritic cells."
It was already known that nicotine and several other compounds in vaping liquids have harmful effects on health. Flavor molecules now join this list, concludes Professor Morissette.