So much for e-cigarettes being a safer alternative to tobacco cigarettes; a new study from UC-San Francisco found that teens who used e-cigs were more likely to move on to regular cigarettes.

The researchers also say that adolescents who started with e-cigs were actually less likely to quit smoking. It seems counterintuitive that people would replace a safer delivery system with a more dangerous one but it could be that people who are inclined to nicotine addiction are more likely to use both products, but the researchers refer to the e-cigs as a “gateway” to tobacco. They also note that the use of e-cigs has doubled among middle schoolers, although still at a low level, going from 3.1% to 6.5%.