The common chemical flavors in electronic cigarettes can alter lung function: study

Boston: A Harvard study reveals that chemicals widely used to flavor electronic cigarettes can alter the lungs' first line of defense against dust and allergens, increasing the risk of diseases such as asthma. The researchers found that two chemicals, diacetyl and 2,3-pentanedione, affected the function of eyelashes – antenna-like protuberances that are present on 50-75% of the cells lining the human airways.

They play a key role in maintaining the human respiratory tract free of mucus and dirt and allow people to breathe easily and without irritation. Altered eyelash function has been badociated with lung diseases such as chronic obstructive pulmonary disease (COPD) and asthma.

"Although the chemicals used to flavor e-cigs are frequently used, little is known about the mechanism of their impact on health," said Quan Lu, an badociate professor at Harvard University in the United States. United. "Our new study suggests that these chemicals can harm eyelashes – the first line of defense in the lungs – by altering gene expression related to eyelash production and function," said Lu.

The study, published in the journal Scientific Reports, is the first to examine the impact of flavoring chemicals on human epithelial cells, which are of the type that lines the lungs. Researchers have already discovered that flavoring chemicals – primarily diacetyl and 2,3-pentanedione – are present in more than 90% of the electronic cigarettes tested.

Diacetyl is also used as a flavoring agent in foods such as butter-flavored microwavable popcorn, baked goods and sweets.
Although it is considered a safe ingredient in foods, evidence suggests that Diacetyl can be dangerous when inhaled. It was previously linked to bronchiolitis obliterans, a debilitating lung disease dubbed "popcorn lung," as it first appeared in workers who inhaled artificial butter at microwave popcorn processing facilities.

After the link between diacetyl lung and popcorn has been reported, 2,3-pentanedione has sometimes been used as a substitute. As part of this study, researchers used new laboratory techniques to examine the impact of diacetyl and 2,3-pentanedione on epithelial cells in a system closely mimicking the airway epithelium. in vivo.

They exposed normal human bronchial epithelial cells (NHBE) to chemicals for 24 hours. They found that diacetyl and 2,3-pentanedione were linked to changes in gene expression that could affect both eyelash production and function.

In addition, the researchers found that even low concentrations of both chemicals affected gene expression, suggesting that current standards for safe exposure limits for workers may not be enough. . According to researchers, there is no such standard for users of electronic cigarettes. "Electronic cigarette users heat and inhale flavor chemicals that have never been tested for inhalation safety," Allen said.