A common misconception about medical marijuana is that if inhaled, it will have detrimental effects on the patient’s lungs. However, according to a 2012 study published in the Journal of the American Medical Association (JAMA), this notion is simply untrue; in fact, this study points to an idea quite the opposite: that medical marijuana just might improve lung health under certain conditions.



About the Study

Spanning 20 years (1985-2006), this longitudinal study—also known as the Coronary Artery Risk Development in Young Adults (CARDIA) study—examined the pulmonary function of 5,115 people across four U.S. cities, taking into account their smoking habits, both tobacco and marijuana. All participants were healthy and between the ages of 18-30 at the time of enrollment in 1985. After undergoing a baseline examination, participants were then examined six times throughout the subsequent 20 years at specific year markers.

In order to measure participants’ pulmonary function, researchers measured FEV1 (forced expiratory volume)—how much air somebody can exhale during a forced breath in the first second after taking as deep a breath as possible—and FVC (forced vital capacity)—the total amount of air exhaled during the FEV test after taking as deep a breath as possible. It’s worth noting that among smokers, the average tobacco user was found to smoke eight or nine cigarettes a day while the average marijuana user smoked around two or three times within 30 days. Also, it’s important to note the study was conducted on smoking of combustable plant material, not the vaping marijuana extracts. Smoking of raw plant flower is not permitted in Pennsylvania. AGRiMED supplies clean, vapable extracts in additional to pills, tinctures, and transdermal delivery methods as part of our product portfolio to Pennsylvania medical marijuana patients.

The Study’s Findings

Not surprisingly, the researchers found that tobacco smoking was associated with a lower FEV1 and FVC. Contrastingly, marijuana smoking was associated with a higher FVC and lifetime exposure was associated with a higher FEV1. Simply, this means that most marijuana users had better pulmonary function than did nonsmokers; tobacco smokers had worse pulmonary function than did nonsmokers or marijuana smokers.

It is important to note that in regards to these findings, the increased lung capacity was associated with low to moderate marijuana use. As marijuana use started to increase up to around 20 times per month, researchers found that FEV1 levels started to plateau or even slightly decrease. As marijuana use got even higher, up to 25+ times per month, researchers did find that FEV1 levels began to decline; regardless, FVC remained at high levels even in these frequent users. The study does admit that it lacked a sufficient number of heavy users, so while their findings reflected the limited number they did study, they were not able to draw any concrete conclusions regarding heavy marijuana use.

The Study’s Impact

These findings are vital to the practice of using medical marijuana for a variety of reasons. First of all, as many esteemed professionals have commented, this study reinforces previous studies on tobacco smoking and its harmful effects on lung health. Additionally, this is one of the longest and most intensive studies conducted on marijuana in regard to lung health, offering great findings for the medical marijuana community to take comfort in—that marijuana use, in fact, helps lung health.

While it’s not 100% clear as to why marijuana use improved lung health, it could be due to the fact that those who choose to inhale marijuana do so by taking deep breaths—referred to by the researchers as “deep inspiratory maneuvers”—and holding them in, potentially stretching the lungs; another theory was that inhaling marijuana resulted in a “strengthening of chest wall musculature.” Though the reasoning is debated, the results are clear: marijuana largely improved lung health in users.

References