People who smoke should try proven cessation tools such as medications and nicotine patches and gums, the American Lung Association and the American Heart Association say.

Still, “it’s a no-brainer” that smokers who switch to e-cigarettes are reducing harm, said Doug Jorenby, clinical services director at UW-Madison’s Center for Tobacco Research and Intervention. “Based on what we know at the moment, it’s almost beyond debate,” he said.

The center conducted an FDA-funded study over the past year comparing people’s experiences with e-cigarettes and regular cigarettes. Results of the study, involving 150 smokers in Madison and Milwaukee, should be available soon.

Jorenby said some people who try to switch from regular cigarettes to e-cigarettes end up using both, which may not reduce harm.

A Centers for Disease Control and Prevention study last month said an estimated 263,000 middle school and high school students who never smoked cigarettes used e-cigarettes in 2013, up from 79,000 in 2011. Non-smoking youth who tried e-cigarettes were twice as likely as those who didn’t to say they intended to smoke regular cigarettes within the next year.