Electronic cigarettes do little to help smokers quit, and could actually increase the likelihood that teens and young adults will start smoking, a new study suggests.

"E-cigarettes will likely cause more public health harm than public health benefit unless ways can be found to substantially decrease the number of adolescents and young adults who vape and increase the number of smokers who use e-cigarettes to successfully quit smoking," principle investigator Samir Soneji said in a news release from the Dartmouth Institute for Health Policy and Clinical Practice.

Soneji and his research team analyzed U.S. data and published research to assess the benefits and harms of e-cigarettes. Their findings were published online March 14 in PLoS One.

"Although the tobacco industry markets e-cigarettes as a tool to help adult smokers quit smoking, e-cigarette use actually only marginally increases the number of adult cigarette smokers who are able to successfully quit," he said.

"On the other hand, e-cigarettes may facilitate cigarette smoking initiation and confer substantial harm to adolescents and young adults once they are introduced to nicotine," Soneji said. He's an associate professor with the institute.

The researchers calculated that e-cigarettes "could lead to more than 1.5 million years of life lost because their use could substantially increase the number of adolescents and young adults who eventually become cigarette smokers," Soneji said.

He urged passage of regulations to make kid-friendly flavors less available and to "reduce the level of known toxins and carcinogens in e-juice."