Sept. 20 (UPI) -- Some flavors of e-cigarettes may aggravate asthma symptoms in vapers, new findings show.
The results, published Friday in Scientific Reports, contradict beliefs that e-cigarettes are a safer alternative to smoking cigarettes.
Past research suggests teens with asthma may also more be drawn to e-cigarettes as a safe alternative to smoking tobacco.
"The majority of e-cigarette smokers use flavored liquids but there is some evidence that flavor additives can be toxic when inhaled," David Chapman, a researcher at the University of Technology Sydney and study lead author, said in a news release.
The researchers studied the effect of e-cigarette flavors Black Licorice, Kola, Banana Pudding or Cinnacide, with and without 12 mg/mL nicotine, on lab mice with an airway disease.
One group of animals was exposed to e-cigarette aerosol for 30 minutes, twice a day, for six days a week. Another group was exposed to room air for the same time period.
The results showed nicotine-free Black Licorice inflamed the airways of the mice, while nicotine-free Cinnacide and all flavors containing nicotine suppressed inflammation.
"This is especially important for those with respiratory disease, whom are vulnerable to the effects of smoking," Chapman said.
The new study supports previous research showing that vaping can harm breathing. Specifically, it pointed to a flavoring agent found in 90 percent of e-cigarettes called diacetyl as the cause of the problem.
"The exact effects on features of asthma were dependent upon the specific flavor, suggesting not all flavored e-cigarettes will have the same consequences on lung health," Chapman said. "This is especially important for those with respiratory disease, who are vulnerable to the effects of smoking,"