Study: Marijuana Smoking Not Associated With Airway Cancers, COPD, Emphysema, Or Other Tobacco-Related Pulmonary Complications

  • by Paul Armentano, NORML Deputy Director July 9, 2013

    Pulmonary complications associated with the regular smoking of cannabis are “relatively small” and far lower than those associated with tobacco smoking, according to a recent review published in the June edition of the scientific journal Annals of the American Thoracic Society.

    The paper – authored by Donald P. Tashkin, MD, emeritus professor of medicine and medical director of the Pulmonary Function Laboratory at the David Geffen School of Medicine at University of California, Los Angeles – is “the most comprehensive and authoritative review of the subject ever published,” according to an accompanying commentary. Donald Tashkin conducted US-government sponsored studies of marijuana and lung function for over 30 years.

    His review finds that although smoking cannabis may be associated with symptoms of chronic bronchitis, studies do not substantiate claims that it is positively associated with the development of lung cancer, chronic obstructive pulmonary disease (COPD), emphysema, or bullous lung disease.

    “[H]abitual use of marijuana alone does not appear to lead to significant abnormalities in lung function,” Tashkin writes. “[F]indings from a limited number of well-designed epidemiological studies do not suggest an increased risk of either lung or upper airway cancer from light or moderate use. … Overall, the risks of pulmonary complications of regular use of marijuana appear to be relatively small and far lower than those of tobacco smoking.”

    Writing in an accompanying commentary, McGill University’s Dr. Mark Ware concludes: “Cannabis smoking is not equivalent to tobacco smoking in terms of respiratory risk. … [C]annabis smoking does not seem to increase risk of chronic obstructive pulmonary disease (COPD) or airway cancers. In fact, there is even a suggestion that at low doses cannabis may be protective for both conditions. … This conclusion will affect the way health professionals interact with patients, parents with teenagers, and policy makers with their constituents. … Efforts to develop cleaner cannabinoid delivery systems can and should continue, but at least for now, [those] who smoke small amounts of cannabis for medical or recreational purposes can breathe a little bit easier.”

    Full text of the study, “Effects of marijuana smoking on the lung,” appears in Annals of the American Thoracic Society.

    35 Responses to “Study: Marijuana Smoking Not Associated With Airway Cancers, COPD, Emphysema, Or Other Tobacco-Related Pulmonary Complications”

    1. joel says:

      I didn’t read the paper, just the abstract by following the link.

      This is bad news, not good news, for people who smoke marijuana. Large airway inflammation, for example, is not good.

      Note the lost of cilia in smokers. I autopsied a young marijuana smoker who died of the swine flu complicated by bacterial pneumonia. Coincidence? Maybe. Bullous changes from smoking marijuana are well known. My autopsy patient had a h/o pneunothorax. He was in his early 20’s.

      Why people think you can inhale a hot, carcinogenic smoke (marijuana burns hotter than tobacco) and not damage your lungs is beyond me.

      What seems to protect marijuana users thus far is that the drug is illegal (death from cirrhosis dropped during prohibition) and mind altering, so you don’t can’t smoke a pack per day. But, give it time. It takes about 30 years of smoking a pack per day to start seeing clinical lung damage. In the 1970’s the lung cancer rate was so low among smoking women that many serious people doubted tobacco caused lung cancer, or that the ladies didn’t inhale, or only Camels caused lung cancer. The rates finally sky-rocketed in the 1980’s. Lag time.

      I haven’t seen any studies on smoking marijuana and alpha-1-antitrypsin deficiency. This is a not uncommon problem. You might want to get tested before you smoke anything.

      Anyhow, enjoy your little vice, but don’t tell people it is harmless.

    2. Steve says:

      The truth is sometimes difficult for people to comprehend. ANY smoke, vapor, oil or other irritant will cause some level of emphysema. EVERYONE has some level of emphysema. The studies indicate that the high levels of macro-emphysema seen in tobacco users are not seen in mj users.

      And of course, ingestion (other than smoking) will not impact lungs at all!

    3. m says:

      Daniel, so I guess all inhalants prescribed by doctors of medicine hurt their patients as this is for sure not clean air. Medicine comes in more ways than you obviously have studied. Yes some medicines even come in smoke form. Of course so much of mmj is consumed other ways. Please study the subject before you quote what you read or heard from some ignorant writer or speaker. Ignorance means not knowing. Ignorance with stigma or political agenda, even over zealous religious judgement, causes many unnecessary problems for the patients, doctors, and society as a whole.

      Michael lr

    4. Daniel says:

      Nothing other than clean air is good for a person’s lungs. There is no study needed for this fact. Any smoke or a substance that is burned, is going to coat the lung.

      I also have to very much doubt the comment made by Ed, regarding smoking cannabis removing his asthma as a teenager and claiming it never came back. Asthma does not have a known cure, period. It (along with other parts of what is commonly known as COPD) only progressively becomes worse.

      What perhaps may happen with some individuals, the smoking of Marijuana would help “deaden” nerve endings which then may create a sense of less felt congestion and after the initial irritation and coughing from use of smoking some Marijuana which would clear some of the mucus out of the lungs, there would not be any real long term or “healing” as per what some would tend to think of use of Marijuana in regards to the lungs and it’s affects on them.

      There may be some real truth to the line of thought that Marijuana is less harmful than a tobacco product on the lungs, but to think it is not harmful would be a false conclusion.

      I do also somewhat support the use of MEDICAL Marijuana, period.

    5. Ed says:

      I’m a 45 year old male and my personal experience is that smoking cannabis eliminated my asthma when I was a teenager and it has never come back. It makes sens to me e because cannabis seems to dilate the broncheal passage ways and acts as an expectorant so it would tend to facilitate breathing and removal of buildup in the passageways. Thanks for this study to validate what I’ve thought for years in spite of the medical industry’s claims.

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