An electronic cigarette is demonstrated in Chicago. Some makers of the liquid nicotine used in electronic cigarettes are using notable brand names like Thin Mint, Tootsie Roll and Cinnamon Toast Crunch to sell their wares. Now the owners of those trademarks are fighting back to make sure their brands aren't being used to sell an addictive drug or being marketed to children. [Photo/IC]

Non-smoking teens who used e- cigarettes are much more likely to smoke conventional cigarettes compared to those who never used e-cigarettes, according to a study out Monday by the U.S. Centers for Disease Control and Prevention (CDC).

The study, published in the journal Nicotine and Tobacco Research, showed that 43.9 percent of U.S. middle and high school students who had used e-cigarettes said they intended to smoke conventional cigarettes within the next year, compared with 21.5 percent of those who had never used e-cigarettes.

Overall, over 263,000 U.S. teens who had never smoked a cigarette used electronic cigarettes in 2013, up from about 79,000 in 2011, said the CDC study, which was based on the 2011, 2012, and 2013 National Youth Tobacco surveys.

"We are very concerned about nicotine use among our youth, regardless of whether it comes from conventional cigarettes, e- cigarettes or other tobacco products. Not only is nicotine highly addictive, it can harm adolescent brain development," said Tim McAfee, director of CDC's Office on Smoking and Health, in a statement.

E-cigarettes are battery-powered devices that look like cigarettes and deliver an aerosol of nicotine and other chemicals. They are promoted as safer alternatives to cigarettes and smoking cessation aids, and also sold in flavors such as chocolate and strawberry that are banned in conventional cigarettes because of their appeal to youth.

In April, the U.S. Food and Drug Administration proposed rules that could eventually ban the sale of e-cigarettes to individuals under the age of 18.