Electronic cigarettes, which are promoted as a way to quit regular cigarettes, may not help people cut down on smoking, according to a recent study HealthDay reported.

Research published in the journal JAMA Internal Medicine suggests that there is not enough evidence to prove that the e-cigarette devices help people quit smoking cigarettes.

Users of the battery-operated devices inhale vaporized nicotine but not tobacco smoke. Unlike conventional cigarettes, there's no tar or carbon monoxide. It's estimated to be a $2-billion business.

"When used by a broad sample of smokers under 'real world' conditions, e-cigarette use did not significantly increase the chances of successfully quitting cigarette smoking," Dr. Pamela Ling, researcher and associate professor at the Center for Tobacco Control Research and Education at University of California, San Francisco, told HealthDay.

For the study, researchers used data reported by nearly 1,000 smokers, 88 of whom used e-cigarettes at the start of the study. After one year, 14 percent of the smokers had quit overall, with similar rates in both groups.

"We found that there was no difference in the rate of quitting between smokers who used an e-cigarette and those who did not," Ling said.

Based on their findings, there was no relationship between e-cigarette use and quitting, even after taking into account the number of cigarettes smoked per day, how early in the day a smoker had a first cigarette and intention to quit smoking, according to Ling.

Their findings are consistent with other studies that have also been conclusive on that score. They also contradict the claims frequently found in e-cigarette advertising, according to Ling.

Researchers suggest that regulations should forbid such claims until theirs is enough evidence.

"Advertising suggesting that e-cigarettes are effective for smoking cessation should be prohibited until such claims are supported by scientific evidence," Ling said.