Bullen and colleagues recruited 657 adult smokers in Auckland who wanted to quit for the study. Nearly 300 got nicotine-containing e-cigarettes while roughly the same number got nicotine patches. Just over 70 people got placebo e-cigarettes without any nicotine. Each group used the e-cigarettes or patches for 13 weeks.
After six months, similar rates of smokers — 6% to 7% — managed to quit after using either the nicotine-containing e-cigarettes or patches. Only 4% of smokers using the placebo e-cigarettes successfully quit.
Among smokers who hadn't managed to quit, nearly 60% of those using e-cigarettes had cut down the number of cigarettes smoked by at least half versus 41% of those using nicotine patches. Smokers were also much bigger fans of the e-cigarettes; nearly 90% of users said they would recommend them to a friend compared to just over half of people who got patches.
Researchers also found similar rates of side effects in smokers that used the e-cigarettes and the patches. The most common side effect in all groups was breathing problems.
The study was published online Sunday and presented at a meeting of the European Respiratory Society in Barcelona, Spain. The e-cigarettes used in the study were provided free by the company and the study was paid for by the Health Research Council of New Zealand, a government funder.
Peter Hajek, an anti-smoking expert at Queen Mary University of London, called it a "pioneering" study and said health officials should seriously consider recommending e-cigarettes to smokers who want to quit or cut down.
"E-cigarettes also have the potential to replace cigarettes as a consumer product, so their value is not just as a treatment," he said. Hajek authored an accompanying commentary in the Lancet. "That could stop the tobacco-related disease and death epidemic if everyone switches to a safer way of nicotine delivery," he said.
Hajek said that even though more studies were needed on the long-term safety of e-cigarettes, there weren't any imminent warning signs.
"E-cigarettes may not be perfectly safe, but even if some currently unknown risk materializes, they are likely to be orders of magnitude safer than normal cigarettes," he said.
The European Union and Britain are planning to regulate e-cigarettes as medical devices, a decision that has provoked criticism from some scientists who argue that would limit their availability to help smokers while cigarettes are not as tightly regulated. It is the tar and other toxins in cigarettes which are deadly, not the nicotine.
In the U.S., the FDA plans to assert regulatory authority over the fast-growing category in the near future. E-cigarettes could also still be regulated as drugs or drug-delivery devices, if they are "marketed for therapeutic purposes" — for example, as a stop-smoking aid.
Bullen suggested e-cigarettes could be monitored like lifestyle or consumer products to avoid restricting their access.
"There needs to be a middle ground where regulation is commensurate with the risk," he said. "For people who are dependent on nicotine, we've got to provide them with a safer alternative ... crushing their availability completely will be bad for public health."