U.S. officials remain skeptical of electronic cigarettes' health benefits for smokers, but another study indicates the devices have real value.

The New England Journal of Medicine (NEJM) recently published the results of a very large study conducted in the U.K. by Queen Mary University of London that found e-cigs are twice as effective at helping people quit smoking as any other nicotine replacement therapy, such as nicotine patches, gum, lozenges, and inhalers -- an indication of the efficacy of e-cigs in fighting the smoking habit.

Woman using a vape pen

Image source: Getty Images.

Stamping out cigarettes

The study was the largest of its kind yet conducted, enrolling almost 900 people who wanted to quit smoking. Half of them were given electronic cigarettes; the other half got some other type of treatment.

Those given e-cigs got an initial starter pack and then had to buy supplies on their own. The nicotine replacement therapy users were given a broad choice of products, and were encouraged to use more than one if they wanted. Many did so, such as using a patch and gum together. They were also permitted to switch products during the trial.

According to the NEJM report, by the end of 52 weeks, 18% of those on e-cigs were still off cigarettes versus 9.9% of those on traditional smoking-cessation therapies. And even if they didn't quit smoking entirely, e-cig users were also more likely to have cut down on their smoking by 50% or more.

Other benefits from e-cig use included larger declines in the incidence of coughing and phlegm production, as well as less nausea, though e-cig users also reported more throat and mouth irritation. There was no real difference in either group with reports of wheezing or shortness of breath.

Digging its heels in

The Food and Drug Administration, however, has yet to find any e-cig to be safer than cigarettes, and as a result, U.S. healthcare providers are reluctant to recommend their use.

The American Academy of Family Physicians (AAFP) says that although the U.K. study seemed well designed, it still had shortcomings. The AAFP reiterated that it "does not endorse e-cigarettes as a cessation device," preferring instead to simply tell smokers they should stop smoking and use FDA-approved therapies. The American Lung Association says, "We only support methods that are FDA approved and regulated."

With the FDA grumbling that it might impose harsh new restrictions on e-cig makers, especially after Altria (NYSE:MO) invested in leading manufacturer Juul Labs, there's enough reason to think it will be a long time before the U.S. medical community ever gets on board.

That's not the case in the U.K., where there is mounting evidence that e-cigs may be the best available smoking alternative. Previously, the government agency Public Health England said e-cigs are 95% safer than traditional cigarettes and has called for them to be made available through the U.K.'s National Health Service within five years.

Check out the latest earnings call transcript for Altria.

Not a complete vindication

An important caveat to the study -- and what perhaps gave the AAFP pause about endorsing the findings -- was that while electronic cigarettes were more effective at helping wean smokers off cigarettes, it came as a result of being accompanied by appropriate "behavioral support," such as counseling (the other group received support as well), which AAFP says is not how real-world e-cig smokers use the product. Also, the e-cigs that were used typically had lower levels of nicotine in them than other commercial e-cigs on the market.

Critics also contend e-cigs merely substitute one addiction for another. At the end of the one-year study, 80% of those in the e-cig group who had quit smoking were still using the devices, while just 9% of those in the group using other means of cessation were still on them.

National Public Radio (NPR), however, quotes the study's author Peter Hajek as saying that despite more people continuing to use e-cigs after quitting, it is easier to quit vaping than it is to quit smoking. Nicotine addiction is an issue, but the risks are lower than with tobacco use. "So from our point of view ... this is not a public health issue anymore," Hajek said.

Because the FDA remains more concerned about minors' use of electronic cigarettes than getting adults to quit smoking, policy decisions in the U.S. may not be as favorable for e-cigs as those made in the U.K. E-cigs may still end up being allowed here, but without a stamp of approval from regulators.