Can Use Of E-cigarettes Or Vaping Lead To Liver Disease?

Gastroenterology Research has retracted a study linking vaping to liver disease after concerns were raised about its methods and findings. Critics say researchers are overstating the harms of use of e-cigarette.

E-cigarettes, also known as vapes, are being promoted as a safe alternative to regular cigarettes for smokers who are trying to overcome their nicotine addiction. But some researchers argue that e-cigarettes contain potentially harmful substances, like nicotine, lead, and cancer-causing agents. Meanwhile, advocates for tobacco harm reduction argue that the potential harms of vaping are being overstated in academic literature.

In June 2022, Gastroenterology Research, a peer-reviewed journal, published a study that linked nicotine vapes to liver disease. Last month, the journal retracted the study after concerns were raised about the article’s methodology, source data processing, and reliability of conclusions, and the authors failed to address these concerns. The paper titled “Association of Smoking and E-Cigarette in Chronic Liver Disease: An NHANES Study,” was formally retracted on June 11.

According to the journal’s editor-in-chief, Robert Wong, objections to the paper were raised in a letter to the editor and the study authors were given time to respond or prepare a rebuttal. Because they didn’t receive any response or rebuttal from the authors, the manuscript was retracted.

Meanwhile, advocates for tobacco harm reduction slammed public health researchers for overstating the harms of vaping in academic literature.

Gregory Conley, director of legislative and external affairs for the American Vapor Manufacturers Association, told Filter that this is not the first case. He pointed out another study connecting vaping to heart attacks, which the Journal of the American Heart Association (JAHA) retracted in 2020.

Critics are also questioning the Gastroenterology Research for not making the letter that prompted the retraction public. It remains unclear as to what went wrong with the paper.

Are e-cigarettes or vaping products really harmful?

The Gastroenterology Research paper stated that e-cigarette users may have higher odds of having liver disease compared to non-smokers. But critics pointed out flaws in the methodology used.

The study is based on the analysis of a publicly available database, the National Health and Nutrition Examination Survey (NHANES). The results found e-cigarette users associated with higher chances of developing liver disease compared to non-smokers.

Ray Niaura, a psychologist and epidemiology professor at New York University’s School of Global Public Health, told Filter that the survey data don’t allow for analysis around timing, and thus it’s impossible to say if someone developed liver disease before or after they began smoking and/or vaping.

Though he is happy that the journal retracted the paper, he insisted that Gastroenterology Research should publish the letter that led to its retraction.

He also noted that e-cigarettes have become the object of research interest for many public health researchers, mostly to discover their potential harms.

Studies highlighting potential harmful effects of e-cigarettes

A study from the University of California and published in JAMA Network Open suggested that switching to e-cigarettes can make smokers more likely to relapse.

One study conducted by researchers from Harvard University and published in the journal Environmental Health Perspectives warned that popular e-cigarette products may contain toxins, endotoxin and glucan, that are associated with asthma, reduced lung function and inflammation.

Another research presented at the European Respiratory Society International Congress raised concern that nicotine-containing e-cigarettes may cause blood clotting and spike blood pressure.