Cannabis and Lung Health [What the Studies Say]

So what’s the deal – is smoking marijuana bad for your lungs or not? Depending on who you talk to, some people say that cannabis smoke is just as dangerous over the long term as cigarette smoke, but others of course, say that you can smoke 10 joints a day for 60 years, and never have a single issue.

So who are we to believe?

In instances like these, there’s really not much else we can do except look to our old friend science. And as such, a brand new study looking at the long-term effects of marijuana inhalation on respiratory function in tobacco smokers was just published by the Journal of Chronic Obstructive Pulmonary Diseases.

Let’s take a look at what it had to say.

What Studies Have Said in the Past

Before we take a look at the new study that was released just this past month (January 2018), it’s important to realize that this topic is something that has been studied rather extensively over the years. In 2001, for example, a study published in Current Opinion in Pulmonary Medicine stated that “regular marijuana use can lead to extensive airway injury and alterations in the structure and function of alveolar macrophages, [which] potentially predisposes to pulmonary infection and respiratory cancer.”

Yikes. That doesn’t sound good, does it?

Likewise, studies published in both the American Review of Respiratory Disease and the academic journal Thorax have indicated that frequent marijuana smoke inhalation may lead to a “higher prevalence of wheezing, cough, and sputum (bronchitis).”

However, more recent studies (2002) from the Journal of Clinical Pharmacology have stated that in both healthy individuals and asthma sufferers alike, a single joint can potentially act as an “acute bronchodilator response,” with a bronchodilator being a drug or tool that is used to widen bronchi in the lungs and thus improve respiratory function.

So what’s anyone to make of this? We’ve literally got some scientific studies saying marijuana leads to a predisposition to lung infection and cancer, while others are saying that it aids in respiration and can even act as a therapy for asthma victims. That’s some pretty conflicting information, if there ever was such a thing.

Variables can Account for Errors in Scientific Data

One of the most crucial aspects of conducting a scientific or clinical investigation is making sure that control is maintained over the test subjects – and over the overall study as a whole. If you’re testing for the effects of long-term marijuana smoke on lung health, for example, how are you going to take into consideration potential variables that the subjects may be exposed to over the course of the study – that is, variables that may have a negative impact on lung health? Have they been smoking tobacco cigarettes as well, for example? And what about air quality – how does the air where each subject lives compare to the air quality of the other subjects?

There are other factors to take into consideration as well, including both the quality of the marijuana being smoked and the method of smoke inhalation. For example if a joint was used, what kind of paper was used to roll it? While organic hemp rolling papers are generally considered to be pretty safe and non-toxic, it’s known that tobacco papers from blunts or cigarettes (spliffs) can contain all of the toxic/carcinogenic ingredients that are found in pre-packaged cigarettes.

And of course, individual genetics is another massive variable in its own right that needs to be taken into consideration. For example, it’s well known that pulmonary diseases (such as COPD) can be hereditary, so how would we know that a decreased lung function – if observed in a clinical study – was in fact attributable to marijuana smoke and not some other factor or variable?

These are all very important things that need to be considered and taken into account long before we (or anyone, for that matter) can truly understand the effects that marijuana smoke has on our long term lung health.

New 2017 Study Looks at the Effects of Long-Term Marijuana Use

The study we aim to talk about (published October 2017 by the journal Chronic Obstructive Pulmonary Diseases) used surveys to examine the possible effects of marijuana smoke on a population of roughly 2,300 individuals (aged 40-80) categorized into three different groups: never smokers, current smokers (marijuana use in the last 30 days), and former smokers (marijuana use over 30 days ago).

Lifetime exposure to marijuana was estimated for both the current and former smoker groups by surveying how many joints and/or bowls they smoked per week on average (for the purposes of the study a joint and a bowl were deemed equivalent). Subjects were categorized as having a “less than” 10-year joint history, a 10-20 year joint history, or a “greater than” 20 joint year history (the term “joint year” was defined as the equivalent of smoking 1 joint/bowl every day for a year … in other words, a subject in the 10-20 joint year category would have smoked on average between 10 and 20 joints per week for a year). Afterwards, subjects in each of the three categories were then compared to subjects in the “never smoker” category (though it is worth pointing out that many of the test subjects were also habitual tobacco smokers).

Results of the study were extremely positive, with authors concluding that “among [the] older adults with a history of tobacco use, marijuana use does not appear to increase risk for adverse lung function.” They go on to say “…there may be no to little increased risk of marijuana use for a further increase in respiratory symptoms or adverse effects on lung function…”

Additionally, the team reported that “neither current nor former marijuana use was associated with increased risk of cough, wheeze, or chronic bronchitis when compared to never marijuana users,” and that “both current and former marijuana use was associated with significantly less quantitative emphysema … when compared to never users, even after adjusting for age … In agreement with other published studies, we also did not find that marijuana use was associated with more obstructive lung disease.”

It is worth noting though that this was not a randomized clinical study – there were no control groups. Rather, data was collected from test subjects via survey.

Final Thoughts on Long Term Cannabis Use and Lung Health

So does this study put us any further along in terms of the never-ending debate on marijuana inhalation and lung health? Well, you take it as you may, but we don’t really think so – it’s great news, don’t get us wrong, at the end of the day it’s just another one of the studies that falls into the “pro” marijuana use category. There are certainly dozens of others that lie firmly in the “con” category.

That being said, probably the best statistic of all to consider when it comes down to chronic marijuana use and lung health is that there has never been a single documented case of pulmonary (lung) disease attributed to cannabis use, while there have been millions for tobacco (cigarette) use. So what does this mean for you — is smoking marijuana bad for your health? Well, according to science, the verdict is still out.

If you want to be on the ultra safe side, though, you can always do away with smoking altogether and switch to edibles instead or CBD oil.

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