The news: Conventional wisdom generally says inhaling any kind of smoke is bad for your lungs, and, to that end, smoking marijuana is just as bad for your health as smoking tobacco cigarettes.
However, according to data recently published in the journal Annals of the American Thoracic Society, inhaling one marijuana cigarette a day over 20 years is not associated with adverse changes in lung health.
In the largest cross-sectional analysis study of its kind, researchers at Emory University in Atlanta found that cannabis exposure and inhalation were not associated with negative spirometry changes, just FEV1 (forced expiratory volume) declines or problems with small airways disease. Additionally, the researchers found that vaporizing marijuana users reported even fewer issues than those who inhaled combusted marijuana.
In other words, unlike tobacco cigarettes and their well-documented highly negative effects on smokers' lungs, marijuana cigarettes cannot be said to have the same correlation. On top of that, the researchers concluded marijuana smoke exposure could be "associated with some protective lung effects among long-term smokers of tobacco," reports NORML.
However, the study found that inhaling marijuana smoke led to an increase in symptoms of bronchitis-like coughing, sore throat and shortness of breath. So, some risks are certainly still present, but they pale in comparison to the same risks when smoking tobacco cigarettes.
"In a large representative sample of U.S. adults, ongoing use of marijuana is associated with increased respiratory symptoms of bronchitis without a significant functional abnormality in spirometry, and cumulative marijuana use under 20 joint-years is not associated with significant effects on lung function," the study's authors concluded. "The pattern of marijuana's effects seems to be distinctly different when compared to that of tobacco use."
Growing science: Previous studies have also shown marijuana to have health effects much different than generally expected, including its effects on pulmonary functions and similar studies on the effects of marijuana smoke on the lungs.
Not only does this data show marijuana smoke isn't as dangerous as tobacco smoke, but that cannabis could potentially be an effective method of treatment for a number of medical issues, considering the myriad of potential uses.
Already, many state have legalized marijuana in one form or another, though most have approved cannabis for medicinal use. And as the body of science behind marijuana's positive aspects grows, you can expect even more states to be jumping on board and legalizing.