The FDA is allowing vaping brand Juul to keep its e cigarettes on the market. Studies from Juul show its e cigarettes are less harmful for adult smokers, who can benefit from switching completely E cigarettes damage blood vessels even if devices don't contain nicotine, study finds Fox News FDA scrutinized for lack of studies showing how e cigarettes may reduce smoking related deaths Fox Business An updated overview of e cigarette impact on human health Respiratory Research Springer Nature Link