Some electronic cigarette companies say that their products help people quit smoking, but the evidence to back up this claim is lacking, a new study finds.
Researchers analyzed information from more than 1,000 people who took part in four previous studies that looked at whether e-cigarettes can improve quitting rates.
After one month, a greater percentage of people who used e-cigarettes had quit smoking, compared with the percentage of people who used a placebo or a nicotine patch. However, after three to six months, there was no difference in the quitting rates among people who smoked e-cigarettes, compared with those who took a placebo or used a nicotine patch.
"Although e-cigarettes are widely promoted and used as a smoking cessation tool, we found no data supporting their long-term efficacy," study researcher Dr. Riyad Al-Lehebi, of the University of Toronto, said in a statement.
E-cigarettes do not burn tobacco. Instead, they vaporize nicotine, and the user then inhales the vapor.
The new findings agree with a 2014 study that found that people who used e-cigarettes in addition to regular cigarettes were no more likely to quit smoking a year later than those who did not use the electronic devices.
A review of 18 studies on e-cigarette safety also found that users sometimes experience side effects, such as a dry cough, throat irritation and shortness of breath. Use of e-cigarettes was also linked with a greater risk of serious problems such as lung inflammation and irregular heart beat — compared with using a nicotine patch while trying to quit smoking.
"Given the potential health risks of using these unproven and unregulated devices, individuals seeking help with smoking cessation should consider other, more well-established options until more research is performed," Al-Lehebi said.
The researchers noted that more robust, long-term studies of the safety and effectiveness of e-cigarettes are needed to see whether or not the devices really may help people quit smoking.
The study was presented this week at the American Thoracic Society International Conference in Denver.