SAN JOSE, United States - E-cigarettes can be an effective tool for smokers aiming to kick their tobacco habit, but officials fear the devices are also creating nicotine addiction among adolescents.
"E-cigarettes show tremendous promise as a tool for helping smokers who don't respond to other approaches for quitting smoking," Wilson Compton, deputy director of the US National Institute on Drug Abuse, said Friday, during a presentation with other health officials.
"What concerns us is very recent data from the US showing surprising high rates of e-cigarette use by teenagers," he said, speaking at the annual meeting of the American Association for the Advancement of Science, in California.
A recent annual survey of more than 40,000 US high school students showed that in the last month, 8.7 per cent of 14-year-olds had used the battery-operated devices that deliver vaporized nicotine into an aerosol inhaled by the user.
And the number only increased with age: 16.2 per cent of 16-year-olds and 17.1 per cent of 18-year-olds had done the same.
"That's a concern because this may be a unique and new pathway to nicotine exposure," Compton said.
In recent months, the US Centres for Disease Control and Prevention (CDC) reported that use of e-cigarettes by young non-smokers had tripled from 2011 to 2013, and warned that nicotine can affect brain development in teenagers.
The US Food and Drug Administration (FDA) in April proposed restrictions on the country's $2-billion e-cigarette industry, such as requiring sellers to enforce a minimum age.
'Far less dangerous'
"Nicotine can be harmful to the growing brain, so it's best if young people avoid it," said Deborah Arnott, head of Britain-based nonprofit Action on Smoking and Health (ASH).
"But if they're going to experiment, it's better to use e-cigarettes, as vaping is far less dangerous than smoking and much less addictive," she said.
"So far in the UK and the US, smoking rates are going down more than e-cigarette use is growing. This would not be the case if vaping really were a gateway into smoking," Arnott added.
In the study of 40,000 US teenagers, only four per cent of 14-year-olds, seven per cent of 16-year-olds and 14 per cent of 18-year-olds had smoked real cigarettes in the last month.
E-cigarettes play an important role in helping users quit or reduce smoking, according to the latest research published in December by the Cochrane Collaboration, an independent, international organisation that evaluates medical research.
The group conducted two studies showing that around nine per cent of those using e-cigarettes were able to stop smoking for at least a year, while only four per cent of those who used placebo e-cigarettes were able to.
Among those who were unable to quit smoking, 36 per cent of those using e-cigarettes were able to cut their tobacco consumption by half, compared to 28 per cent in the placebo group.
"There are likely public health benefits from e-cigarettes if they provide a pathway for smokers to give up tobacco use," said Roy Harrison, professor of environmental health at Britain's University of Birmingham.
"There is evidence that this can happen, and little doubt that e-cigarettes are much less harmful to the smoker than tobacco," he said.
"However, if adolescents who have never used tobacco take up e-cigarette use, this is a matter of profound concern as they are deliberately exposing themselves to a highly addictive substance."