The American Association for Cancer Research and the American Society of Clinical Oncology released a joint statement on Thursday to discourage the use of electronic cigarettes, citing uncertainty regarding their safety.

The statement was published in the AACR’s Clinical Cancer Research and ASCO’s Journal of Clinical Oncology by a committee of cancer experts chaired by Roy Herbst ’84 GRD ’84. Herbst is  currently a professor of medicine and pharmacology and Chief of Medical Oncology at the Yale Cancer Center and Smilow Cancer Hospital. In it, the authors discourage the use of e-cigarettes as part of smoking-cessation programs and among young people because of the lack of complete research on their health ramifications. As a result, the committee issued policy recommendations to decrease the gap in regulatory standards between cigarettes and e-cigarettes and to address the risk of encouraging e-cigarette smoking among youth and former nonsmokers.

“It is patently untrue that e-cigarettes are safe,” said co-author Benjamin Toll, professor of psychiatry and director of the Smoking Cessation Service at Smilow Cancer Hospital. “There is not enough safety data to make this claim.”

Some researchers remain concerned about e-cigarettes’ role in enabling smoking among those who would have successfully quit without them.

Yale professor of psychiatry Suchitra Krishnan-Sarin said that smokers’ ability use e-cigarettes almost universally — even in locations where cigarettes are illegal — can actually force them to remain dependent on nicotine, rather than helping them fight an addiction.

Thomas Lynch ’82 MED ’86, who serves as Director of the Yale Cancer Center and Physician-in-Chief of the Smilow Cancer Hospital, said that e-cigarette use can also grow out of a desire to avoid a social stigma against cigarettes.

“Smokers see [e-cigarettes] as a socially acceptable way to smoke,” Lynch said. “They’re not doing it to be healthy.”

This stigma has been shown to inspire some smokers to try quitting, Krishnan-Sarin added.

The statement also attempts to dispel some perceived illusions about the comparative safety of the electronic alternatives. Though the chemicals in the nicotine liquid found in e-cigarettes are marketed as safe, studies have shown the vapor to contain formaldehyde and heavy metals, which can be harmful to both first- and second-hand smokers, Toll said. The statement’s authors also call for further research on these chemicals, though most researchers still agree that tobacco is far more harmful than the nicotine solution could be, professor of public health Jody Sindelar said.

Until more research can be done, the authors recommend that people who want to quit smoking use other cessation aids, also calling for better access to data regarding e-cigarette safety.

“The exponential growth of these products in the face of not fully understanding them — that’s what’s scary,” Krishnan-Sarin said.

Seton Hall University law professor Jordan Paradise said that, because e-cigarettes are not strictly tobacco products, they face more lenient regulation. Bodies like the Food and Drug Administration thus cannot label the products with health warnings or control their flavors, which, Toll noted, could have important implications on youth use.

“If you regulated [e-cigarettes] in the same way tobacco was regulated, at least it would be an even playing field,” said Howard Forman, professor of diagnostic radiology, economics and public health. “You can’t sell cigarettes in bubblegum flavor.”

Limiting youth consumption of e-cigarettes is more important than stopping current smokers from using them, Herbst said. Krishnan-Sarin, who has studied focus groups of Connecticut high school and middle school students, e-cigarettes’ flavors are one of their most appealing traits among youth. As a result, several of the committee’s recommendations prioritize curbing youth consumption of e-cigarettes with stricter regulation of flavors and age checks and decreased youth-oriented marketing.

Toll noted that the task is nuanced, adding that it would not be ideal to follow the example of cigarette regulation and ban all flavorings, for example. While banning sales to minors would be advisable, Toll said that if a flavor was found to appeal to adults and help them quit smoking, banning that flavor be counterproductive.

With many tobacco companies beginning to acquire e-cigarette companies, they are beginning to receive strong financial and legal backing in their fight against stricter regulation, potentially making the new policy statement particularly timely.

“There’s a huge effort against acting on these recommendations,” Lynch said. “That will make it harder for the policy statement to bring about results, but it is still very important because this is one of the first groups that has gotten together to talk about it.”

E-cigarettes first entered the American market in 2007.