A new study is providing more evidence e-cigarette usage opens the door to regular smoking.

(diego_cervo, ThinkStock)

The study, published in JAMA Pediatrics - The Journal of the American Medical Association - found that 11 of 16 e-cigarette users between the ages of 16 and 26 had taken up tobacco smoking with a year of starting electronic cigarette use. This is compared to 128 of 678 participants, about 19 percent, who did not use e-cigarettes at the start of their smoking experience.

The lead author of the study is Dr. Brian Primack, an associate professor of medicine and pediatrics at the University of Pittsburgh School of Medicine.

"Our report did find that initial e-cigarette users were very likely to progress to regular cigarette smoking," Primack said.

He said no one is quite sure why that transition is taking place, but there is a lot of speculation.

"It is much more palatable to use an e-cigarette for the first time," he said. "Most e-cigarettes deliver nicotine. This is sort of the biochemical approach. They deliver nicotine, but they deliver it more slowly than traditional cigarettes. So it is sort of a perfect starter cigarette in a way."

Primack said a new user can start with e-cigarettes, and then progress to regular cigarettes when they become accustomed to the nicotine and when they need more.

He said there is a lot we do not know about the health effects of using e-cigs, and until we know more, they should be at least be as tightly regulated as real cigarettes.

Primack says there are also a few other reasons younger people may reach for e-cigarettes first. One is simply the flavorings.

"Young people traditionally like things, or are more acclimated to, things that are in candy-type flavorings. So this is why, again, young people do not immediately start to drink Jack Daniels, they are drinking some kind of fruity wine cooler," he said.

Another is that it is just more palatable, according to Primack,  as opposed to the burning, the coughing that happens when people start to use traditional cigarettes. He also  speculates that another reason may be, "sort of the, cool, technological devices" that are involved.

"That may also be compelling to young people," he said.