How harmful is cannabis smoke compared to tobacco?
It is well known that smoking is bad for you, but research has shown that smoking cannabis appears to be less harmful than smoking tobacco. The study described below suggests that cannabis may even have properties that could benefit lung health. In this blog, you will read how this research was set up and what the results were.
Uncertainty about the harmfulness of cannabis
When you smoke tobacco, you inhale the harmful substances produced by burning tobacco, which then enter the lungs. Cannabis smoke shares many similarities with tobacco smoke. For a long time, it was assumed that cannabis was just as unhealthy as tobacco when smoked. Some studies showed that cannabis, like tobacco, could cause inflammation and damage to the lung mucosa.
On the other hand, there were also studies that found no direct link between cannabis use and declining lung function or lung disease. So, there was much division in this field. A groundbreaking study from 2012 changed this. This study, Association Between Marijuana Exposure and Pulmonary Function Over 20 Years, conducted by Pletcher et al., aimed to determine the impact of cannabis smoke on lung function compared to tobacco smoke.
The remarkable thing about this study is its design. More than 5,000 people were followed over twenty years. Although it is an older study, the results remain relevant due to its high reliability and careful setup.
Cannabis as harmful as tobacco: the study
The study into the risks of cannabis and tobacco was conducted as part of the CARDIA study (Coronary Artery Risk Development in Young Adults). A total of 5,115 people participated, representing a broad cross-section of average cannabis and tobacco users in the United States. Participants were between 18 and 30 years old and healthy.
The study began with a baseline examination of the participants, followed by six follow-up assessments. A lung function test was conducted in the first year and then after 2, 5, 10, and 20 years. At the end of the study, 69% of participants were still involved.
An important aspect of this study is how lung function was tested and what was measured. Two measurements were taken. The first was FEV1, or forced expiratory volume in the first second after exhalation. This measures the maximum volume of air that can be exhaled in one second after a full breath. The second measurement was FVC, or forced vital capacity. This measures the total volume of air that can be exhaled after a full breath. There is no time limit for this test.
The results of the study: Is cannabis as harmful as tobacco?
So what did this study reveal? Is cannabis as harmful as tobacco? It showed that tobacco use caused a decrease in both FEV1 and FVC, with both short-term and long-term exposure. Tobacco clearly has a negative impact on lung function. But what about cannabis? That turned out not to be the case.
Cannabis versus tobacco: What do FEV1 and FVC measurements show?
Among light users, the researchers observed an increase in certain lung measurements (FVC and FEV1). This may indicate a larger lung volume, although it is not clear whether this is actually beneficial for health. As a result, the total lung capacity of cannabis smokers even increased over the 20-year study period compared to those who did not use cannabis!
Additionally, both FVC and FEV1 steadily increased when participants began smoking more from the start of the study. This meant their lung capacity also grew proportionally. However, the results were less favorable for heavy users.
In the long run, they did not fare as well. With increased exposure to cannabis smoke, the rise in FEV1 flattened and even declined. Yet even very heavy marijuana use was associated with long-term FEV1 values that did not significantly differ from baseline and were often still higher.
So, can conclusions be drawn for cannabis users? Is smoking cannabis less harmful than smoking tobacco? It indeed seems that when smoking cannabis, you will generally not experience a decline in lung capacity. Some measurements even suggested a possible protective effect, although this cannot yet be definitively confirmed. Tobacco, on the other hand, only has negative effects on the lungs and other organs of the body.
Other research on tobacco and cannabis
Although the study discussed above was well-designed, it is always better to look at the results of multiple studies. Fortunately, these exist. A study from 2013 (Effects of Marijuana Smoking on the Lung), published in the Official Publications of the American Thoracic Society, also suggested that there appears to be no link between cannabis use and lung cancer, whereas such a link does exist for tobacco.
This study found no clear association between cannabis and lung diseases such as cancer, emphysema, or COPD. However, this does not mean cannabis is completely harmless; further studies are needed to understand this better.
A 20-year study from Emory University in 2015 (The effects of marijuana exposure on expiratory airflow) also showed that cannabis did not lead to harmful effects on the lungs. Researchers found indications that cannabis use might influence the negative effects of tobacco, but since this was based on self-reporting, it should be interpreted with caution.
Based on these studies, cannabis appears in some respects to be less harmful than tobacco. Still, more research is needed before definitive conclusions can be drawn.
Nonetheless, these results may have positive implications for society. Patients using medical cannabis may have less reason to worry about effects on their lungs. Insurers may also be more inclined to cover medical cannabis, as multiple studies suggest it has fewer negative effects on lung health than previously thought.
How harmful is cannabis smoke really? Important nuance from a scientific perspective
Although several studies suggest that cannabis may be less harmful to the lungs than tobacco, it is important to place these findings in context. Especially with health information such as lung health and smoking behavior, nuance is essential.
Limitations of the research: what do scientists themselves say?
One of the most frequently cited studies is the 20-year study by Pletcher et al. (2012), published in JAMA. This study showed that light to moderate cannabis users did not experience a significant decline in lung function. In fact, some measurements, such as FVC, even slightly increased. However, the researchers themselves emphasize that this does not mean cannabis use is healthy. These results apply to controlled and limited use. For heavier users, they observed a flattening or decline in lung capacity (Pletcher et al., 2012).
A similar point was made in Tashkin’s 2013 study, published in the Annals of the American Thoracic Society. This study found no direct link between cannabis use and lung cancer, but also emphasized that the absence of evidence is not evidence of absence of risk. More research is needed, especially in the long term and with frequent use.
Sources:
Pletcher, M. J., Vittinghoff, E., Kalhan, R., et al. (2012). Association Between Marijuana Exposure and Pulmonary Function Over 20 Years. JAMA. https://jamanetwork.com/journals/jama/fullarticle/1104848
Tashkin, D. P. (2013). Effects of Marijuana Smoking on the Lung. AnnalsATS. https://www.atsjournals.org/doi/full/10.1513/AnnalsATS.201212-127FR
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This blog was written by: Mirjam Sprenger, a copywriter for Taaldomein.
She mainly focuses on writing about health, nutrition, and supplements, with reliability and clarity of information as her top priorities.
DISCLAIMER
Note: this blog is intended solely for informational purposes and not as medical advice. Smoking cannabis may carry risks, especially with frequent or long-term use. Always consult a doctor if you have health concerns.
