Washington: Electronic cigarettes, already facing bans and scrutiny by US regulators, have received a new slap on the wrist from scientists.

A report released on Thursday suggests the devices may be a gateway to old-fashioned, cancer-causing smokes for teens.

A study suggests that youth who smoke e-cigarettes are more likely to move on to old-fashioned cigarettes. Credit:Reuters

Youths who reported using an e-cigarette had six times the odds of smoking a traditional cigarette compared with those who had never tried the device, a study published in the journal JAMA Pediatrics found. E-cigarette use did not stop young smokers from partaking in regular cigarettes as well.

The global market for e-cigarettes may top $US5 billion ($5.5 billion) this year, Euromonitor International estimates show. Makers of the devices, including the largest US tobacco company Altria Group, market them online and on television, where traditional tobacco ads are banned. Some have added flavours such as bubble gum to the nicotine vapour that may have extra appeal for youths. That allure is why the US Food and Drug Administration needs to restrict the devices, anti-smoking advocates say.