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More studies are helping regulators to decide what role e-cigarettes could play in anti-smoking efforts.

The Food and Drug Administration (FDA) is currently evaluating the safety of e-cigarettes, which are battery-powered versions of cigarettes that can contain varying amounts of nicotine but don’t expose users to the potentially harmful byproducts of tobacco smoke such as tar and carbon monoxide. Instead, they inhale nicotine vapors, which the device’s advocates say is safer than smoking conventional cigarettes, and makes e-cigarettes a viable way to kick the habit as well.

And the latest study on e-cigarettes, published in the journal Lancet, supports that claim. In the first clinical trial comparing e-cigarettes and nicotine patches in helping people to quit smoking, both methods proved equally successful. After a 13-week smoking cessation program, similar numbers of smokers who used e-cigarettes remained smoke-free after six months as used nicotine patches.

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The researchers, from the University of Auckland in New Zealand, recruited 657 smokers eager to kick the habit. One group received placebo e-cigarettes with no nicotine, another group received a 13-week supply of e-cigarettes with 16 mg of nicotine and the third was provided with a 13-week supply of nicotine patches.

Among the e-cigarette smokers, 7.8% had quit by the end of the study, while 5.8% of those using the patch had stopped lighting up, a difference that wasn’t statistically significant, meaning that the two interventions had essentially the same impact.

These results support other data suggesting that e-cigarettes can help smokers to quit; earlier this year, a study published in the journal PLOS ONE found that those using e-cigarettes were more likely to quit smoking, even if they didn’t want to. Italian researchers from the University of Catania set out to test whether using e-cigarettes would help smokers cut back on their smoking over a year, but by the end of the study, 13% of the group with the highest dose of nicotine in their e-cigarettes (7.2 mg) were no longer lighting up.

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The FDA is likely to consider these studies, among others, as it considers what to do about e-cigarettes. While the agency currently doesn’t regulate them, it intends to do so soon, and determine what role, if any, the devices can play in smoking cessation. One strategy that Mitch Zeller, the FDA’s director of the Center for Tobacco Products may consider in assessing tobacco products involves the so-called continuum of risk, which takes into account that there is a spectrum of tobacco products that exposes consumers to varying amounts of nicotine, and therefore varying levels of health risks. On one end live the traditional cigarettes, and on the other are products like nicotine patches and lozenges, which are designed to wean smokers of their dependence on nicotine. E-cigarettes may fall somewhere in between, since they can help smokers to quit, as the latest evidence shows, but may also serve as an introduction to cigarettes for younger smokers. A recent study showed that in the U.S., for example, e-cigarette use has doubled among high schoolers and middle schoolers, and that 76% of e-cigarette users also smoked conventional cigarettes.

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Still, in a paper Zeller authored in the journal Tobacco Control, he argued that accepting a sliding scale of risk may be the most practical way to curb smoking rates, rather than regulating tobacco products from an all-or-none perspective. “Anyone who would ponder the endgame must acknowledge that the continuum of risk exists and pursue strategies that are designed to drive consumers from the most deadly and dangerous to the least harmful forms of nicotine delivery,” he wrote.

He also admits that this reflects an evolution in this thinking, and, some public experts hope, in that of the FDA, which has long been criticized for not being an effective advocate for public health against the tobacco industry.