A study by a team from the New York University (NYU) College of Dentistry has turned a spotlight on the relationship between e-cigarette use and gum disease, the oral microbiome and the immune system.
The gum disease known as periodontitis affects nearly half of all adults over 30 in the United States, while about 30% of Australians over 15 have moderate or severe periodontitis.
Periodontitis causes gums to become inflamed and recede from the teeth, creating pockets where oral bacteria can stimulate further disease. Immune responses can drive inflammation and worsening periodontitis. In severe cases, teeth can loosen or fall out and jaw bones depleted.
Cigarette smoking is a well-known risk factor for gum disease, but not a lot is yet known about the impact of e-cigarettes on oral health.
“Unlike smoking, which has been studied extensively for decades, we know little about the health consequences of e-cigarette use and are just starting to understand how the unique microbiome promoted by vaping impacts oral health and disease,” explains Scott Thomas, co-first author of the NYU study.
The study compared 84 adults who had mild to severe gum disease at the start of the study and used conventional cigarettes, e-cigarettes, or had never smoked either.
The results suggest that while e-cigarettes may not be quite as bad for your gums as conventional cigarettes, they’re riskier than not smoking at all.
The highest proportion of severe disease was found in the cigarette smoking group, but the e-cigarette group contained more cases of severe disease than the non-smoking group.
Matt Hopcraft, an associate professor at the University of Melbourne Dental School and CEO of the Victorian Branch of the Australian Dental Association, says the findings are consistent with current knowledge about the risks of e-cigarettes to oral health.
“Although the evidence base is weak, available data suggests an unhealthy impact of vaping on periodontal health,” he says, pointing to a recent systematic review.
The NYU study also identified certain groups of bacteria that were significantly elevated in the oral microbiome of e-cigarette users, including genera associated with periodontitis.
“Vaping appears to be driving unique patterns in bacteria and influencing the growth of some bacteria in a manner akin to cigarette smoking, but with its own profile and risks to oral health,” says Fangxi Xu, the study’s other co-first author.
To complete the picture, the researchers also measured levels of various cytokines – proteins that direct the human immune response. They observed correlations between bacterial groups, cytokine levels and clinical measures of periodontitis severity.
For example, the inflammatory cytokine TNF-alpha was significantly elevated among e-cigarette users compared to cigarette smokers and non-smokers, and was also positively correlated with certain bacteria that were more dominant in e-cigarette and conventional cigarette users compared to non-smokers.
“We are now beginning to understand how e-cigarettes and the chemicals they contain are changing the oral microbiome and disrupting the balance of bacteria,” says Deepak Saxena, a professor of molecular pathobiology at NYU who co-led the study.
“Whilst we know the significant impacts of cigarette smoking on periodontal disease, and links to oral cancers, and the emphasis [is] therefore on assisting patients to quit tobacco, vaping does not appear to be a safe transition away from tobacco,” says Hopcraft.