Some flavors of e-cigarettes may aggravate asthma symptoms in e-cigareete users. New research contradicts beliefs that e-cigarettes are a safer alternative to smoking cigarettes. "The majority of e-cigarette smokers use flavored liquids but there is some evidence that flavor additives can be toxic when inhaled". David Chapman Researcher and study lead author The researchers studied the effect of e-cigarette flavors with and without 12 mg/mL nicotine, on lab mice with asthma. According to UPI, researchers found that some specific flavors increased airway inflammation in the mice. The new study supports previous research showing that vaping can harm breathing.