CBD Vaping Worse For Lungs Than Nicotine Vaping, Study Suggests

Vaping CBD may lead to more severe lung damage than vaping nicotine-based products, according to a new study from researchers at the Roswell Park Comprehensive Cancer Center in New York.

Published in the journal Thorax, the study examined rats exposed to aerosols produced by commercially-available CBD and nicotine vapes and compared any differences in the rats’ behavior and physical health. They found significantly higher levels of lung damage and oxidative stress in the rats exposed to the CBD-based aerosol.

The researchers also exposed human white blood cells and epithelial cells to the aerosols, finding that the CBD aerosol displayed a higher toxicity to human cells than the nicotine aerosol.

Previous research into the impacts of vaping has largely focused on nicotine-based products. However, the Roswell Park researchers say that their findings underscore the importance of also considering CBD and other cannabinoid-based vapes in future research, and advise that healthcare providers should include CBD vapes when asking about smoking history, for example.

Rat study finds more lung damage after vaping CBD

Throughout late-2019 and early-2020, the United States was struck by a mysterious outbreak of e-cigarette or vaping product use-associated lung injuries (EVALI). Fortunately, this outbreak has now largely abated, but its presence did thrust cannabis vape products into the spotlight after a diluent thickener found in illicit market THC products was identified by the US Centers for Disease Control and Prevention (CDC) as a contributor to the illness.

Following this outbreak, there has been more awareness of the differences between cannabinoid vape products and nicotine-containing vapes. In addition to containing a different main ingredient, these two types of vapes are often formulated in different ways. As the researchers behind this new study explain in their paper, these different solvents, flavors, or terpenes could be a factor in the impact that these products have on lung health, which is why, say the researchers, they need to be investigated.

For this new study, the researchers exposed two groups of mice to filtered air or aerosols generated from either a CBD-containing vape pod or a nicotine-containing vape pod from two well-known commercial brands. After two weeks of regular exposure intervals, the rats were assessed for any inflammation and/or lung damage using histology, flow cytometry, and quantifying various levels of proinflammatory cytokines and protein levels in the rats’ bronchoalveolar lavage fluid (BAL).

The researchers found that:

• The number and severity of areas of tissue damage in the lungs were significantly greater after inhaling CBD aerosol, compared to nicotine aerosols.
• Myeloperoxidase (MPO) activity was significantly greater following exposure to CBD aerosol; MPO is an enzyme that promotes inflammation and damage to lung cells.
• Greater inflammatory changes and higher oxidative stress levels were also seen after inhaling CBD aerosols.
• CBD aerosol exposure significantly lowered the number of pulmonary interstitial macrophages in the lungs. These immune cells play an important role in reducing inflammation and protecting against infection.

Based on these preclinical findings, the researchers believe that further study on the health effects of long-term CBD vape use is warranted. Other types of cannabinoid-based vapes, such as THC-containing vapes, should also be evaluated, they say.

“We believe this is the first-ever report on what happens to various immune cell types and markers of damage and inflammation measured in the lung following in vivo inhalation exposure,” the study’s lead author, Dr. Yasmin Thanavala, a professor and research scientist in the Roswell Park Comprehensive Cancer Center Department of Immunology, said in a statement.

Human cell study also shows dangers

In addition to the rat exposure study, the researchers also used in vitro cultures of human white blood cells and epithelial cells to study the potential impacts of both aerosol types on the human body.

They found that human neutrophil cells – a type of white blood cell that plays an important role in helping the immune system fight infection – were killed off at a higher rate when exposed to CBD aerosols, compared to nicotine aerosol. The CBD aerosols were also more toxic to the human small airway epithelial cell cultures and greatly affected their cell morphology, leading to a disruption of the lung epithelial barrier’s integrity.

“Our findings suggest that vaping cannabis may not only cause significant lung injury, but can also increase susceptibility to respiratory infections, lead to poor responses to prophylactic vaccinations or cause worsening of symptoms in patients with underlying pulmonary inflammatory disease,” Thanavala said.

“So it’s not enough for care providers to ask people, ‘Do you smoke?’ The next step is, ‘Do you vape?’ If the answer is yes, you need to ask, ‘Do you vape nicotine or do you vape cannabis?’”

The study does recognize its own limitations. For example, the CBD aerosol and nicotine aerosol exposure methods used were identical, but the researchers say that CBD vape products might be used differently from nicotine vape products (less frequently, for instance) in real-world conditions, and so there is a possibility that the methodology here could be improved as more information on real-world usage patterns is collected.

The research did not identify the reason for the differing effects of the CBD and nicotine aerosols. However, the researchers did note that higher levels of carbonyl compounds were identified when the CBD-containing aerosol was analyzed, suggesting that this formulation could have been more susceptible to thermal degradation.