E-cigarettes have been hotly debated in the U.S. both as cessation tools and gateway devices. New evidence in California from the American Journal of Public Health found that smokers who have ever used e-cigarettes are less likely to cut back on cigarette consumption in the future.

Study results indicated that smokers with any history of e-cigarette use were less likely after one year to decrease cigarette smoking, or completely quit for one month or more, than smokers who have never smoked e-cigarettes.

The study included more than 1,000 smokers, ages 18 to 59 who had smoked at least 100 cigarettes in their lifetime, using data from a California Smokers cohort. Participants were asked about their awareness of e-cigarettes, tobacco behavior and intention to quit and quit attempts.

“These findings are at odds with data from trials and experimental studies demonstrating that e-cigarettes have some positive influence on quitting behavior — comparable to that of the nicotine patch — although these studies showed very low rates of success,” the authors explained.

The AJPH study comes on the heels of another study from the Centers for Disease Control and Prevention which found that high school and middle schools students use e-cigarettes more often than cigarettes. Both studies reinforce the need for more information about the health implications of e-cigarette use and their connection to cigarette use,

Members of the public health community remain skeptical of e-cigarettes and cite many concerns.

“If the e-cigarette companies want to market these to help people quit, then do the clinical trials and apply to the FDA … but they don’t want to do that. They want to market them widely,” Centers for Disease Control and Prevention Director Tom Frieden said in a recent interview with the Los Angeles Times.

AJPH study authors, led by Wael Al-Delaimi, MD, PhD, attest to the need for more studies on e-cigarettes, writing that “given the rapidly growing use of e-cigarettes, these findings are important for generating further studies that specifically look at the role of e-cigarettes as cessation tools among the general population of smokers, and directly address the validity of claims regarding cessation efficacy.”

Further, public health professionals worry that e-cigarettes appeal to youth with potentially misleading claims of cessation.

“I have seen the ads for these products, and they take us back to the Joe Camel days,” said Georges Benjamin, MD, executive director of APHA, in a 2013 interview with Governing magazine. “My experience with the tobacco industry tells me the likelihood is it will do more harm than good. I know the tobacco industry, and I don’t trust them one bit.”

For more about the study and other new public health research, visit the American Journal of Public Health.