Why can't scientists agree on e cigarettes? Science The Guardian A sweeping scientific review is raising new concerns about the long term health effects of vaping. Nicotine based e cigarettes may pose a serious cancer risk, according to a major new review that challenges the Latest Cochrane Review finds high certainty evidence that nicotine e cigarettes are more effective than traditional nicotine replacement therapy (NRT) in helping people quit smoking Cochrane Best E Cigarettes to Quit Smoking E Cigarette Reviews and Rankings