My good friend Julian used to jog for 7 miles every single day. Back when I was working in the States, he used to be a bartender at a renowned local restaurant during the night — that left him with a lot of free time during the day.
He would wake up at 9 am, stretch, meditate, and either go jogging on the beach or riding his bicycle for 2 hours without stopping. After he has done his morning/noon routine he’d usually run a couple of errands, do the laundry, drink some coffee, and go to work at 5 pm, where he would bartend until 11 pm.
Oh, he was also a daily cannabis smoker. I always admired how he managed not to get out of breath during his jogging/cycling sessions and then be able to work throughout the night shift. Although he smoked 2 joints a day all by himself, he never coughed or complained of being out of breath. Not even once.
He used to say that cannabis not only didn’t have an impact on his lungs (or he thought so) but rather it enhanced their performance. I thought all this was nonsense, of course. Throughout the year I’ve been constantly told that smoking cannabis is not different from smoking tobacco when it comes to lung damage, especially if a regular joint is mixed with some tobacco (a spliff).
Another friend of mine from New York told me a couple of days ago about his experience with smoking and how it presumably affected his lungs. I will refer to him as Matt for the sake of anonymity:
“Last year I ran half a marathon and made it in just below 3 hours. Right before it started, though, I smoked a joint.”
He felt as if cannabis enhanced his breathing capacity that kept him going for so long. He “stayed more in the zone.” However, he said, this only works when he’s running — it actually impedes his swimming abilities — “I wouldn’t be high if I were a lifeguard.”
But what does science say about all this?
According to Harvard Health, citing a study that was published in the Journal of the American Medical Association (JAMA), people that smoked one joint a day for a period of 7 years didn’t experience any lung damage. Further, the study argued, moderate smoking aided lung function, simply because of all of the inhaling acts as a “lungs and chest muscles workout.”
The researchers responsible for conducting the JAMA study were closely associated with the Coronary Artery Risk Development in Young Adults study. This study, initiated in the mid-1980s took 20 years and included 5,115 participants — both males and females, aged 18–30 years.
The goal was to monitor risk factors for cardiovascular disease and whether prolonged cannabis use affected lungs the same way as tobacco smoking did, and also whether there was a risk of developing chronic obstructive pulmonary disease (COPD).
Pot and tobacco usually share the same substances when inhaled, such tar and toxic gases, thus, experts have argued, the risk of developing COPD associated with cannabis use might be the same as with tobacco use.
However, earlier studies on cannabis use have presented unclear findings on the matter. Although inhaling the substance’s gases might lead to phlegm production and coughing, many short-term studies argued, there was no substantial evidence to support the claim that cannabis adversely affected lung function.
How the Participants Were Examined
The conducted research took into consideration all of the participants’ past and recent smoking habits. Tobacco use was measured by the typical way — pack-years — which is equivalent to 365 packs that come out as around 7,300 units of cigarettes a year. On the other hand, cannabis was measured by joint-years, where one joint-year is analogous to one smoked joint a day for a year, i.e. 365 joints/year.
The results for the daily tobacco smokers showed that lung function tests declined as the daily and yearly use increased. However, the findings for cannabis smokers were quite different — lung function test scores improved until the daily and yearly use increased significantly. That is, up to 10 joint-years, which is equivalent to 10 joints a day for a year. After the smoker had reached this limit, the tests started to decline.
These findings were for the forced exploratory volume (FEV1), which measures how much air a person can exhale during a forced breath and also measures whether the bronchi are blocked or narrowed by the phlegm in the smoke. However, on the forced vital capacity (FVC) test, which measures the amount of air our lungs can hold, results showed that “there were higher scores that increased with greater lifetime exposure at 10 joint-years and beyond.”
According to the researchers in the study, the primary reason behind this to happen is mainly in the way cannabis is being consumed — via deep inhalations that could stretch the tissues in the lungs, thus expanding lung volume.
Although fascinating, these findings in no way do prove that cannabis is not harmful for your lung function. What hasn’t been taken into consideration is that every single weed joint is different — in size, potency, and so on. Nevertheless, such non-clinical trials shed at least some light on the matter.
But that’s just one point of view; What do other studies say about all this?
What I’ve noticed after reading a dozen of research papers on the matter, is that tobacco and cannabis smoking are actually more different than I thought they would be. Although the respiratory picture differs from individual to individual, the effects both types of smoking have on your body are not the same.
One study by L. Ribeiro, from the Imperial College London Institute of Clinical Sciences, argues that chronic cannabis use is often associated with symptoms that are similar to those of chronic tobacco use in individuals, like shortness of breath, wheeze, cough, and sputum production. Further, cessation of cannabis use results in a reduction in symptoms associated with respiratory problems.
According to the study, long-term marijuana users are not associated with shortness of breath, when it comes to larger studies:
“This suggests that cannabis smoke causes chronic bronchitis in current smokers but not shortness of breath or irreversible airway damage.”
Also, Ribeiro argues that researchers still do not know why marijuana use doesn’t lead to the development of chronic obstructive pulmonary disease in chronic smokers. Two possible explanations would be the persistent bronchodilator effects, i.e. the offsetting airway narrowing or the anti-inflammatory and immunomodulatory effects the THS has.
As for lung cancer, there are obvious, clear associations between tobacco and cannabis use when it comes to developing the disease. This connection has long been the foundation of raising the possibility that like tobacco, marijuana could also be a cause of lung cancer. Yet, the evidence is still scarce to prove such a link, which is the same as with chronic lung disease.
According to another study from 2016, cannabis use does cause chronic bronchitis, such as tobacco use, however, further work might be needed to justify the effects pot has on lung function.
Further, a German study from the same year, conducted by K. Rasche and J. Yayan, from the University of Witten/Herdecke in Wuppertal, argues that cannabis use can weaken the immune system, which in turn may lead to pneumonia.
Also, chronic marijuana consumption may cause airway obstruction and may pose a potential risk for developing lung cancer, as based on immunohistopathological and epidemiological evidence. However, again, lung cancer and cannabis use do not have a clearly-defined link in-between.
According to the American Lung Association, cannabis use causes chronic bronchitis and damages the cell linings of the large airways, leading to cough, wheeze, and phlegm production. However, the amount of cannabis smokes that eventually leads to such problems was not mentioned in their report.
Further, heavy (chronic) cannabis smokers are linked to:
Cases of air pockets in between both lungs and between the lungs and the chest wall, as well as large air bubbles in the lungs among young to middle-aged adults.
Still, this is not a fact, as researchers still can’t tell whether this happens more often with cannabis smokers than the rest of the population.
Additionally, according to a scientific paper in the European Respiratory Journal:
The effects of cannabis on lung function remain unclear.
Also, as with tobacco, smoking marijuana has been associated with bronchitis symptoms and airway inflammation. Nevertheless, there is little evidence of the latter one causing airflow obstruction.
In another report, it’s being argued that there is “moderate evidence of no statistical association” between smoking marijuana and the development of lung cancer.
The Bottom Line
Today, some people view cannabis use as something relatively unharmful and health-beneficial. However, others view it as something that has ill long-term effects on your body, especially your lung function. The debate is still raging whether the negatives outweigh the positives.
There is not much qualitative difference between smoking cannabis and tobacco, with the only main contrast being that the former one contains THC and is being inhaled in a slightly different way. The amount of daily smoking also differs significantly — with the threshold being one pack of cigarettes a day and one joint a day.
Although some sources point at the harmful effects smoking cannabis has on your lung function (ex. developing bronchitis), there are still many unknowns. Most of the clinical studies conducted so far can’t say for sure what the dangers are of inhaling pot smoke.
In most of the studies I had read I noticed a pattern: each of them pointed at the possible development of lung cancer, but none of them proved that the illness had any correlation to smoking cannabis. Obviously, the effects of marijuana are highly individualistic and not yet fully known, which leaves the researchers with the future task to better understand the long- and short-term effects of cannabis on lung function and the overall risks the drug poses.
Thank you for taking some time to read my article! If you wish to read more written by me, check my Medium page:
Viktor Marchev — Medium
For the past couple of months, I’ve been talking to a lot of friends about psychedelics, and LSD in particular…
If you are further interested in psychedelics and mental-health, I recently wrote about whether smoking can damage your brain cells, and how psychedelics could become the “new weed.”
Can Smoking Cannabis Damage Your Brain Cells?
A scientific insight into arguably the biggest debate surrounding the drug.