Study: Association Between Marijuana Exposure and Pulmonary Function Over 20 Years

On January 11 2012 the Journal of the American Medical Association published a study with research contributed by many health experts, analysing the the association between Marijuana exposure and pulmonary function over a span of 20 years. It was known at the time that Marijuana shared many of the same constituents as tobacco smoke, but it was unknown whether Marijuana smoke had any similar adverse effect that tobacco smoke has shown to have on the pulmonary function.

The study was based on a cohort of over 5000 men and women in the US and collected repeated measurements of pulmonary function and smoking over 20 years. This included a control group of tobacco smokers so that an equal comparison between the effects of the two substances could made.

They had found that Marijuana consumption was almost as popular as tobacco consumption was. While they were able to find that Marijuana smokers did exhibit symptoms such as mucosal injury and inflammation as well as increased respiratory symptoms such as cough, phlegm production, and wheeze, similar to that seen in tobacco smokers, analyses of pulmonary function and lung disease have failed to detect clear adverse effects of marijuana use on pulmonary function. The study concluded saying occasional and low cumulative marijuana use was not associated with adverse effects on pulmonary function however they also stated that their findings do suggest an accelerated decline in pulmonary function with heavy use and a resulting need for caution and moderation when marijuana use is considered. They noted that their sample for heavy users were a minority within the cohort and that their findings were imprecise, more specific studies would need to be conducted for further research.

As smoking Marijuana is increasingly common, understanding whether it causes lasting damage to lung function has important implications for public health messaging and medical use of marijuana.

Source: https://jamanetwork.com/journals/jama/fullarticle/1104848