MINNEAPOLIS - E-cigarettes, or vaping, may be a less dangerous way to use tobacco, but a new study finds they can be a gateway for teens and young adults to becoming smokers.

The National Academies of Sciences, Engineering and Medicine looked at the potential harms and benefits of vaping. They found e-cigarette use can be a way to quit smoking. It can also be a way to get young people addicted to nicotine.

"E-cigarettes cannot be simply categorized as either beneficial or harmful," said David Eaton, dean of the Graduate School of the University of Washington in Seattle, who chaired the committee.

"In some circumstances, such as their use by nonsmoking adolescents and young adults, their adverse effects clearly warrant concern. In other cases, such as when adult smokers use them to quit smoking, they offer an opportunity to reduce smoking-related illness," Eaton said.

The report found the e-cigarettes deliver fewer toxins than conventional cigarettes do, but a lot depends on the particular formulation and the user.

The Food and Drug Administration has said it would regulate e-cigarettes, but last summer, the new FDA Commissioner, Dr. Scott Gottlieb, extended the timeline to 2022.

There are still many unknowns about e-cigarette use. For example, there's not enough evidence to say if they can cause cancer or disrupt pregnancy. Vaping does raise heart rate and blood pressure, but the absolute risks of heart disease remain unknown

Tobacco use is the No. 1 cause of both heart disease and cancer.