[marijuana vaporizer vaping vape]Eduardo Munoz/Reuters * MILLIONS OF AMERICANS VAPE, BUT LITTLE IS KNOWN ABOUT THE COMPREHENSIVE HEALTH EFFECTS OF E-CIGARETTES. * THE NATIONAL ACADEMIES OF SCIENCE, ENGINEERING, AND MEDICINE AIMED TO ADDRESS THAT DEARTH OF KNOWLEDGE WITH A NEW REPORT ON E-CIGS. * IN LINE WITH THE ACADEMIES' PREVIOUS APPROACH TO OTHER DRUGS, THE REPORT POOLS ITS FINDINGS INTO CATEGORIES BASED ON HOW MUCH EVIDENCE THERE IS TO DRAW A CONCLUSION. * TWO KEY FINDINGS FROM THE REPORT SUGGEST THAT WHILE VAPING MAY HELP ADULTS QUIT SMOKING CONVENTIONAL CIGARETTES, THE PRACTICE MAY ALSO ENCOURAGE YOUNG PEOPLE TO START. ------------------------- It's been almost a decade since the first vape pen hit store shelves. The whiteboard marker-sized devices, which vaporized liquid nicotine rather than burning tobacco and creating tar, were designed as a healthier alternative to cancer-causing conventional cigarettes. Since then, thousands of models of vape pens have been made available, but a question among public health researchers continued to linger: Do these devices help smokers quit or glorify a potentially unhealthy habit? The answer, according to a large new report from the National Academies of Sciences, Engineering, and Medicine, is a little bit of both. While vaping may help adults quit conventional cigarettes, the practice may also encourage young people to start, the authors of the report found. Still, although vaping comes with health risks, it is likely to be far less harmful overall than smoking conventional cigarettes. ”E-cigarettes cannot be simply categorized as either beneficial or harmful,” David Eaton, the chair of the committee that wrote the report and the dean and vice provost of the Graduate School of the University of Washington, Seattle, said in a statement. Eaton said that in certain circumstances — such as when teens use them and become addicted to nicotine — e-cigarettes' "adverse effects clearly warrant concern." But in other cases — like when adults turn to e-cigs to quit smoking — "they offer an opportunity to reduce smoking-related illness.” [Martin Borne, co-founder of electronic cigarette retailer ]Thomson Reuters For his report, Eaton and his team reviewed roughly 5,000 studies and narrowed down their analysis to include findings from more than 800 papers. In line with the Academies' previous approach to other drugs, the new report pools its findings on e-cigarettes into categories based on how much evidence there is to draw a conclusion. When there is only limited evidence that there's a relationship between two things, such as vaping and cancer, the researchers use the phrase "limited evidence." The same logic applies when there is conclusive evidence for such a relationship. Here are some of their key findings: * YOUNG PEOPLE WHO VAPE ARE AT A HIGHER RISK FOR EVER USING A CONVENTIONAL CIGARETTE than young people who don't — substantial evidence. * EXPOSURE TO NICOTINE FROM VAPING IS HIGHLY VARIABLE and depends on the device and the e-liquid — conclusive evidence. That said, the report also notes that experienced users can and do use e-cigs in a way that allows them to get a comparable amount of nicotine from the devices as they would from a regular cigarette. * Except for nicotine, EXPOSURE TO POTENTIALLY TOXIC SUBSTANCES FROM E-CIGS IS SIGNIFICANTLY LOWER compared with conventional cigarettes — substantial evidence. * While there is substantial evidence that VAPING RESULTS IN SYMPTOMS OF DEPENDENCE, there is moderate evidence that THE RISK AND SEVERITY IS LOWER FOR E-CIGS THAN FOR REGULAR CIGARETTES. Again, this appears to depend on factors like the type of device and the e-liquid used. * SWAPPING E-CIGARETTES FOR CONVENTIONAL CIGARETTES REDUCES USERS’ EXPOSURE to many of the toxins and cancer-causing agents in regular cigarettes — conclusive evidence. There is also substantial evidence that completely switching to e-cigs from conventional cigarettes reduces short-term negative health outcomes in organs like the lungs and heart. * Studies in animals — but not yet in humans — suggest that LONG-TERM VAPING COULD INCREASE THE RISK OF CANCER — limited evidence. * While there is moderate evidence that TEENS WHO USE E-CIGARETTES MAY SEE INCREASED COUGHING WHEEZING, AND WORSENED ASTHMA SYMPTOMS, there is no available evidence on whether or not e-cigs cause respiratory disease. * There is no available evidence whether or not vaping affects pregnancy or fetal development. * Although there is conclusive evidence that e-cig use increases airborne concentrations of key pollutants and nicotine in indoor environments, SECOND-HAND EXPOSURE TO NICOTINE AND POLLUTANTS IS LOWER FROM E-CIGS than from regular cigarettes. * E-cigarettes can explode and cause serious injury — conclusive evidence. * Exposing oneself to e-liquids, either from drinking or touching them, can cause seizures, brain injury, and vomiting — conclusive evidence. Despite these conclusions, the big question of whether e-cigarettes have an overall positive or negative impact on public health remains unanswered. "Given their relatively recent introduction, there has been little time for a scientific body of evidence to develop on the health effects of e-cigarettes," the authors write in their report. In other words, only time will tell. NOW WATCH: How the ancient Greeks proved Earth was round over 2,000 years ago