The American Heart Association, an old foe of the tobacco industry, has taken an official position in the debate over electronic cigarettes.

It’s not a fan.

In a policy statement issued Sunday, the organization called for stricter regulation of the battery operated devices which contain nicotine, but not tobacco, and produce vapor instead of smoke.

“Recent studies raise concerns that e-cigarettes may be a gateway to traditional tobacco products for the nation’s youth, and could renormalize smoking in our society,” said Nancy Brown, CEO of the American Heart Association.

Some say e-cigarettes are a safer alternative to the real thing, or could even help smokers quit altogether. The AHA didn’t categorically reject the idea, noting some “surprising” findings.

“For example, currently available data suggests that e-cigarettes appear to be less harmful than traditional cigarettes. And in some cases the product could help people quit smoking,” the organization said in a press release. However, it cautioned that “those observations are based on a limited pool of medical research without long-term results.”

E-cigarettes have only been in the American market since 2003 and there are few long-term studies of whether smokers have successfully used them as a tool to quit smoking. Some studies show smokers continue to use both types of cigarettes.

“If someone refuses to quit, we’re not opposed to them switching from conventional to e-cigarettes,” said Aruni Bhatnagar, a professor of medicine at the University of Louisville in Kentucky who led the 10 researchers and physicians who wrote the policy statement. “Don’t use them indefinitely. Set a quit date for quitting conventional, e-cigarettes and everything else. We don’t think that will be the long-term or useful way to look at it because e-cigarettes may continue and fuel nicotine addiction.”

E-cigarettes don’t have tar and carbon monoxide, among the harmful ingredients in cigarettes that cause cancer and other health problems, but the AHA expressed concern that exhaled e-cigarette vapor may still expose people to toxic chemicals, including nicotine which has been shown to increase blood pressure.

“We must increase the pace of research and understand the full range of health consequences before we allow this Trojan horse of nicotine back into society,” Brown said.

The organization called for e-cigarettes to be treated like other tobacco products with a ban on the sale and marking of e-cigarettes to youth and regulation of how they are made and sold. In April, the Food and Drug Administration proposed rules that would ban the sale of e-cigarettes to kids under 18. But according to the AHA, the proposal doesn’t do enough to protect children.

Broadcast ads for regular cigarettes have been banned since the 70s but e-cigarette ads are everywhere. The AHA is concerned that kids are targeted through social media ads and that they might find e-cigarette flavors like bubble gum or chocolate appealing. They also want the agency to act faster to require child-proof packaging given the spike in calls to poison control centers related to liquid nicotine used in e-cigarette.

Related: When the FDA said it would regulate e-cigarettes, the reaction was swift.