Cigarette smoke has a greater impact on the health of respiratory tract than marijuana smoke or vaping, according to new research by UC Davis.
The interdisciplinary study analyzed the metabolites (molecules produced by cellular chemical reactions) of the exhaled breath of the participants to analyze how the airways responded. The researchers found that tobacco smoke, in particular, increased inflammation and oxidative stress. Their article was published in Respiratory research.
“We have not measured the chemicals that come out of cigarettes or marijuana, we have measured the responses of the epithelial cells of the respiratory tract, as well as certain systemic responses,” said pulmonologist Nicholas Kenyondirector of UC Davis asthma network and co-ennior author on the study. “Metabolites talk to us a lot about oxidative stress and inflammation.”
The study recruited 254 participants, with 132 using a tobacco or marijuana product, sometimes both. The researchers collected an exhaled expiration condensate, which is the fog that people see when they breathe on a mirror.
From there, the team used mass spectrometry To analyze the oxylipin content in the condensate collected. Oxylipins are signaling molecules based on lipids often associated with inflammation and oxidative stress. Researchers found that these metabolites were significantly upwards in tobacco smokers, which means that they have increased by activity. The responses to oxylipin were less dramatic among the participants who vapued tobacco products. For marijuana smokers, oxylipine profiles were much closer (but not identical) of the non-users.
“When we look at the signatures of the Marijuana smokers, they look closer to the non-users and non-smokers than tobacco smokers, and it was a surprise for us.”–Nicholas Kenyon
“Cigarettes increase these inflammatory fatty acids, but we have not seen it almost as much with marijuana and marijuana products,” said Kenyon. “When we look at the signatures of the Marijuana smokers, they look closer to the non-users and non-smokers than tobacco smokers, and it was a surprise for us.”
These results diverge from Anterior cell culture studieswho showed that smoke of tobacco and marijuana generates significant oxidative stress and inflammation. This study is the first of its kind with humans.
Interdisciplinary collaboration
The study is the last effort of a 20 -year collaboration between the researchers UC Davis Pulmonology and the engineers who helped develop the devices used to isolate the condensate of breathing.
“We have found a way to collect exhaled expiration condensates in a way that provides enough volume to analyze it,” said Cristina Davisco-ennior author of the study, professor of Mechanical and aerospace engineering and vice-chancellor associated for research. “To recover it, we had people expired through a long cooled glass tube with dry ice, and which condenses these particles for collection.”
Using this non -invasive approach, the team has been collecting breathing libraries so -called for about five years to better understand asthma and other conditions. “Our question in this study,” said Davis, “is the way biology is changed when people make life choices such as smoking or vaping.”
Future studies to shed more light on the health of respiratory tract
This is one in a series of studies to better understand how tobacco and marijuana affect the health of the respiratory tract. In the coming months, the team will start to see how these choices affect people with asthma and other pulmonary conditions.
“Participants in this study were mostly healthy people,” said Kenyon. “But we have patients in the pulmonary clinic who have asthma, mpoc or other pulmonary diseases, and we want to know how their respiratory tract react to tobacco or marijuana smoke. Do they have a similar answer to healthy people or is it worse because their respiratory tract are already damaged? ”
The group can also examine other inflammatory biomarkers, as oxylipine responses may not tell the whole story.
“We focused on these fatty acid metabolites, which had been examined previously in cellular models, but there are other inflammatory markers that we could investigate,” said Kenyon. “We are likely to throw a more complete overview of the biomarkers to validate these results.”