A small U.S. study raises new questions about whether using electronic cigarettes will lead people to quit smoking, adding to the debate over how tightly the products should be regulated.

The study, which looked at the habits of 88 smokers who also used e cigarettes, was published as a research letter in the journal JAMA Internal Medicine on Monday. It found that smokers who also used e cigarettes were no more likely to quit smoking after a year, compared to smokers who didn’t use the devices.

Outside experts say the small number of respondents, and a lack of data on whether they intentionally used e cigarettes to help them quit smoking, mean the findings from the Center for Tobacco Control Research and Education at the University of California, San Francisco can’t take the place of much more rigorous study on the subject.

E cigarettes were first introduced in China in 2004 and have since grown into a $2 billion industry. The battery powered devices let users inhale nicotine infused vapors, which don’t contain the harmful tar and carbon monoxide in tobacco.

At issue is how strictly U.S. health regulators should control the products. Advocates say e cigarettes can help smokers quit. Public health experts fear they can serve as a gateway to smoking for the uninitiated, particularly teenagers. Leading U.S. brands include blu by Lorillard Inc and products from privately held NJOY and Logic Technology.

A previous report from the UK found that people who use e cigarettes primarily want to replace traditional cigarettes.

“We did not find a relationship between using an e cigarette and reducing cigarette consumption,” Rachel Grana, the lead researcher on the new study, told Reuters Health.

Grana and colleagues at the University of California, San Francisco analyzed 2011 survey data collected from 949 smokers. Of those, 88 reported using e cigarettes.

When the researchers looked at those smokers’ responses a year later, they found that the people who reported using e cigarettes in the 2011 survey were no more likely to quit smoking than the people who didn’t use e cigarettes.

For those who were still smoking in 2012, using e cigarettes also didn’t appear to change how many traditional cigarettes people smoked per day.

The researchers note that the small number of participants who reported using e cigarettes may have limited their ability to detect a link between quitting smoking and using the device.

Dr. Michael Siegel, who was not involved with the new research, told Reuters Health that the new study had several design flaws, including that the researchers did not know why some of the participants tried e cigarettes or how long they had used them. Siegel is an expert on community health at Boston University School of Public Health and has studied e cigarette research.

By comparing people who smoked regular cigarettes and those who smoked e cigarettes, the researchers are assuming “that the groups are exactly equivalent in terms of their motivations and their levels of addiction to cigarettes,” Siegel said. “You can’t make those assumptions. You’re not dealing with comparable groups.”

In an emailed statement, Grana and fellow researchers acknowledged that they did not have information on the participants’ motivations to use e cigarettes, but said their analysis took into account other factors known to be linked to quitting smoking, such as their stated intention to quit and how many cigarettes they already smoked each day.

“These factors may also reflect motivations to use e cigarettes, as e cigarettes are frequently marketed and perceived as cessation aids,” they wrote. “While these factors predicted quitting as expected, we found that e cigarette use did not predict quitting.

Siegel also pointed out that only about eight percent of the people surveyed said they had any intention to quit smoking within the next month. He hopes people will reserve judgment on e cigarettes until randomized controlled studies considered the “gold standard” of medical research are published.

“We need solid data that’s based on solid science before we make decisions,” he said. “I hope no one would take this research letter and make any conclusion based on it.”

E-cigarettes won’t help you quit, study finds

“Advertising suggesting that e cigarettes are effective for smoking cessation should be prohibited until such claims are supported by scientific evidence,” Ling said.

For the study, Ling’s team analyzed data reported by 949 smokers, 88 of whom used e cigarettes at the start of the study.

One year later, 14 percent of the smokers had quit overall, with similar rates in both groups.

“We found that there was no difference in the rate of quitting between smokers who used an e cigarette and those who did not,” Ling said.

There was no relationship between e cigarette use and quitting, even after taking into account the number of cigarettes smoked per day, how early in the day a smoker had a first cigarette and intention to quit smoking, Ling added.

However, the researchers noted that the small number of e cigarette users may have limited the ability to find an association between e cigarette use and quitting.

The report, published online March 24 in JAMA Internal Medicine, also found that women, younger adults and people with less education were most likely to use e cigarettes.

One expert said the study is flawed and shouldn’t be taken seriously.

“It’s an example of bogus or junk science,” said Dr. Michael Siegel, a professor of community health sciences at Boston University School of Public Health.

“That’s because the study does not examine the rate of successful smoking cessation among e cigarette users who want to quit smoking or cut down substantially on the amount that they smoke, and who are using e cigarettes in an attempt to accomplish this,” Siegel said. “Instead, the study examines the percentage of quitting among all smokers who have ever tried e cigarettes for any reason.”

Many of the smokers who tried e cigarettes may have done so out of curiosity, Siegel said.

“It is plausible, in fact, probable, that many of these 88 smokers were not actually interested in quitting or trying to quit with electronic cigarettes,” he said. “These products have become very popular and have gained widespread media attention, and it is entirely possible that many of these smokers simply wanted to see what the big fuss is all about.”

Calling that a “fatal flaw” in the research, Siegel said it “destroys the validity of the authors’ conclusion.”

It would be a tragedy, he said, if policy makers use the study to draw conclusions about the effectiveness of e cigarettes for smoking cessation purposes.

Erika Ford, assistant vice president for national advocacy at the American Lung Association, said the study confirms what is already clear “e cigarettes are not associated with quitting among smokers.”

Ford noted that most e cigarette companies no longer make claims that their products help smokers quit. “But there is a need for the FDA U.S. Food and Drug Administration to begin their oversight of these products. It’s time for the FDA to find out which products are making no smoking claims and which ones might be in violation of current law,” she said.

The FDA plans to introduce regulations for e cigarettes, but hasn’t yet. In the past, the agency has warned companies about making false claims and for poor manufacturing practices.

More information

For more information on quitting smoking, visit the American Cancer Society.