Following recent statewide bans on specific varieties of e-cigarettes as a result of hundreds of illnesses and several deaths across the country, new findings published in Scientific Reports are shedding light on how some e-cig flavors could worsen symptoms of asthma and other respiratory diseases, reports EurekAlert!

For the study, researchers from Australia and the United States exposed mice to various e-cig flavors with or without nicotine, such as black licorice, kola, banana pudding and cinnacide. Scientists then allowed some rodents to inhale e-cigarette aerosol for 30 minutes twice a day for six days each week while a second group breathed room air for the same amount of time.

Results showed that some flavored e-cigs—even those without nicotine—might change airway function in individuals suffering from respiratory illnesses by either exaggerating or suppressing inflammation. In addition, certain flavors increased airway sensitivity and the level of tissue scarring.

“This is especially important for those with respiratory disease, who are vulnerable to smoking,” said David Chapman, PhD, a researcher at the University of Technology Sydney and the study’s lead author. “The majority of e-cigarette smokers use flavored liquids, but there is some evidence that flavor additives can be toxic when inhaled.”

Chapman added that the exact effects on symptoms of asthma depended on the specific flavor of the e-cig, which suggests that not all flavored e-cigarettes have the same impact on lung health.

Investigators urged e-cig manufacturers to exercise caution when promoting flavored e-cigs to folks who may suffer from asthma and said these products should be restricted.

For related coverage, read “Can Smoking E-Cigarettes Damage Your DNA?” and “Can Vaping Increase Cardiovascular Disease Risk?