New York, Sep 4 (IANS): Assumed by many as a safe alternative to cigarette smoking, electronic cigarettes or e-cigarettes as they are popularly called may, in fact, promote use and addiction to illicit drugs, says a study.

E-cigarettes may function as a "gateway drug" - a drug that lowers the threshold for addiction to other substances such as marijuana and cocaine, the findings showed.

"While e-cigarettes do eliminate some of the health effects associated with combustible tobacco, they are pure nicotine-delivery devices," said co-author Denise Kandel, professor from the Columbia University Medical Center (CUMC) in the US.

"Nicotine clearly acts as a gateway drug on the brain and this effect is likely to occur whether the exposure comes from smoking cigarettes, passive tobacco smoke or e-cigarettes," said co-author Eric Kandel, who is also a professor at CUMC.

E-cigarettes have been touted as a tool to curtail the use of conventional cigarettes and reduce the harmful health effects of combustible tobacco.

But in the light of the skyrocketing popularity of e-cigarettes, particularly among adolescents and young adults, the researchers said that more effective prevention programmes need to be developed for all products that contain nicotine.

"Our findings provided a biologic basis for the sequence of drug use observed in people," Eric Kandel noted.

"One drug alters the brain's circuitry in a way that enhances the effects of a subsequent drug," he added.

The researchers reviewed Denise Kandel's earlier work on the gateway hypothesis and on the role of nicotine as a gateway drug, reported in a paper published in the journal Science in l975.

The current study appeared online in the New England Journal of Medicine.