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Does Marijuana Cause Lung Damage?

By on January 27, 2013

Summary (click to view)

• Marijuana and tobacco smoke contain similar cancer-causing compounds
• Marijuana smoke also contains anti-cancer and anti-tumor compounds known as cannabinoids (eg. THC and CBD)
• Studies show that regular marijuana use does not harm lung function or lead to lung cancer
• Experts believe THC may have a protective effect on the lungs
• Marijuana smokers are still at risk of mild conditions like chronic bronchitis – Most people are aware that tobacco use can lead to numerous lung problems, including impaired breathing and, in some cases, cancer.

While usually seen as less harmful, smoking marijuana is also thought to be bad for your lungs. But is this a myth or reality?

Marijuana Vs. Tobacco

The smoke from burning marijuana flowers contains several cancer-causing compounds, similar to those found in tobacco smoke.

Worse, cannabis smoke deposits a hefty amount of carcinogen-containing tar into the lungs – up to 4 times as much as cigarettes do, according to some studies. This is due to the way marijuana joints are usually rolled (loosely packed and unfiltered).

On the other hand, the smoke from marijuana contains a set of unique chemicals known as cannabinoids (eg. THC and CBD), which are not found in cigarette smoke. Numerous studies have found cannabinoids to have significant anti-cancer and anti-tumor effects.

This key difference is believed to play a role in the different outcomes that marijuana and tobacco have on the lungs.

What The Studies Show

Over the past decade, two large-scale studies have set out to determine the impact of heavy, sustained marijuana use on the lungs.

The first of these studies was led by Dr. Donald Tashkin – a federal researcher and lung specialist who has conducted over 20 years of research on marijuana and the lungs through generous grants from the National Institute on Drug Abuse (NIDA).

In 2006, Dr. Tashkin co-authored a study involving over 2,000 people, which found that, unlike tobacco, marijuana use did not increase the risk of lung cancer, even in individuals who reported smoking over 20,000 marijuana joints in their lifetime. On the contrary, the results seemed to show a reduction in cancer risk.

“We hypothesized that there would be a positive association between marijuana use and lung cancer, and that the association would be more positive with heavier use… What we found instead was no association at all, and even a suggestion of some protective effect.” – Dr. Tashkin

The second study was published in 2012 by a separate team of researchers from the University of California. It was the largest study ever to be conducted on marijuana smokers and involved a sample of over 5,000 adults. The researchers followed their subjects over a 20-year period and found that regular marijuana use – defined as a joint a day for 7 years or a joint a week for 20 years – had no impact on lung function.

Both studies included a sample of tobacco smokers for comparison, and both were able to confirm what we already know – cigarette smoking is directly correlated with lung cancer and impaired lung function. On the other hand, marijuana doesn’t seem to pose the same risks.

The Explanation

Although some experts have been baffled by the results of the two studies mentioned above, Dr. Tashkin points to an obvious explanation. He notes that the THC compound in marijuana may protect users against lung cancer by counteracting the effects of other cancer-causing compounds.

This theory is supported by an abundance of evidence that demonstrates the anti-tumoral and anti-cancer effects of various cannabinoids, including THC. In fact, studies involving rats have found THC to help fight tumor growth specifically in cases of lung cancer.

“The THC in marijuana has well-defined anti-tumoral effects that have been shown to inhibit the growth of a variety of cancers in animal models and tissue culture systems, thus counteracting the potentially tumorigenic effects of the procarcinogens in marijuana smoke.” – Dr. Tashkin

Other properties of THC may explain why marijuana users are not at risk of chronic obstructive pulmonary disease (COPD). COPD is a long-term lung disease that commonly affects tobacco smokers, but does not appear to occur in marijuana users.

“We don’t know for sure… but a very reasonable possibility is that THC may actually interfere with the development of chronic obstructive pulmonary disease.” – Dr. Tashkin

Risks of Marijuana Smoke

Although marijuana smokers may have little to worry about when it comes to cancer and impaired lung function, studies show that marijuana use can still lead to mild lung problems like chronic bronchitis.

Chronic bronchitis is caused by inflammation of the airway. The condition is characterized by the following symptoms:

Persistent cough
Extra mucus/phlegm production

Studies show that patients without noticeable impairment of lung function can still be suffering from chronic bronchitis. Unfortunately, there is no medication that can be prescribed for symptoms of chronic bronchitis caused by smoking. The best method of prevention and treatment is to simply stop smoking – even just for a temporary period of time.

Vaporizing — Is it Safer?

If you suspect you may be suffering from chronic bronchitis and stopping marijuana use is not an option, investing in a vaporizer may be your best bet. A study published in 2010 showed that marijuana smokers who switched to vaporizing experienced significant reductions in symptoms following one month of use.

Health professionals recommend vaporizers for most patients who use medical marijuana. Vaporizers allow the plant matter to be heated enough for cannabinoids to be released, but not enough to cause combustion, thereby eliminating the harmful by-products normally found in smoke.

By using a vaporizer, the risks of airway inflammation associated with marijuana smoke may be avoided.

  • BillyBoy80


  • xlxTrinityxlx

    Thank God for this article. I just used all of this info to shit on my parents in the argument that marijuana was unhealthy for me and my asthma. They now respect me more after realizing I’m not throwing my life down the drain.

    • dbspambox

      As a regular user myself, I think you need to be aware that it has a detrimental effect on short term memory, and I personally would never recommend regular use for anyone under the age of 18 (or maybe even 21). Brains never stop developing, but adolescence is especially important. I wasn’t using daily until I was well into my 20s. It’s been over 10 years now and I’m still very smart and excel at my high functioning job (in IT). My memory has always been bad, but weed has made it a little worse. I’ve also recently switched to vaporising and my lungs feel better than ever. And I’m also a mild asthmatic.
      The other thing is that smoking anything still puts tar and carbon monoxide into your blood, so if recovering from surgery, or have cuts and stuff, your risk of infection is increased, and you won’t heal as fast. There are some very good and fun and portable vaporisers out there. They do take some practice to use though.

      • bonghits rule

        I have been smoking 35 plus years daily and alcohol is way worse in all aspects….. so live your life as you see fit, who cares what anybody else thinks. they probably don’t pay your bills so tell then M Y O B

      • Draggy

        It all depends on the person. Even when I get high my short and long term memory is still fine! I am a Scorpio however.

    • none

      We were just trying to help you honey. we love you

      • minusobama

        Your parents don’t want to hear you coughing all the time!

        • minusobamadipshit


      • mary chang

        Indeed. Spreads the word! Marijuana has been ILLEGAL for 70+ years! And what are the results?…

        *Today marijuana is America’s #1 cash crop.

        *Marijuana is stronger and easier to get than ever before, albeit much more expensive than it should be. To smoke casually from the “black market”, it will run you $100/month. This is much more expensive than it needs to be. More expensive than my cell phone ($20/month from Tmobile), car insurance ($25/month from InsurancePanda), netflix ($10/month), and gym ($15/month from Planet fitness) COMBINED!!! Would you rather put money into the hands of violent gangs and drug dealers… or into taxes for schools, hospitals, public infrastructure, etc.???

        *Today American kids can buy marijuana easier than they can buy a beer.

        *There are over half a million Americans in jail right now for non-violent drug crimes.

        *Today marijuana is the #1 source of income for violent drug gangs and drug cartels who are richer and more dangerous than ever before.

        *Guns are illegal in Mexico yet Mexican drug cartels are buying machine guns, rocket launchers, grenades, airplanes, armored vehicles, anti-aircraft guns, and even submarines.

        *The DEA has been having sex parties funded by drug cartels.

        *The ATF/DOJ has given thousands of guns to drug cartels.

        I have this stupid thing I do called THINKING, and clearly I can see that marijuana prohibition can never work! America should have learned this simple lesson from alcohol prohibition!

        • Sigourney Lorriane

          If it’s legal, it will go into the hands of our government and they will be able to properly regulate it. Then, young people can get weed the same way they get alcohol and smokes. Problem solved.

      • Larry Hinze

        Yes darling. Now get off your lazy stoney rectum and take out the trash. You have been so unmotivated keep eating our Gir Scout Cookies.

      • Carl Meuel

        Well its all on how you consume it. To me, eating it is the best way. When I smoke through a bowl or joint my lungs get jacked pretty quickly. I’ve never tried vape tho. 4 times the tar than cigarette smoke is pretty bad and I’ve seen full color 3d images of lungs from long time use of marijuana and it’s not pretty. Your parents were going off what they heard before and as a parent I wouldn’t want my kids smoking it but if they want to use, they could eat it. Most parents are trying to be jerks, their trying to protect someone they love more than their own lives.

        • stefany scolos

          It’s a very sad situation indeed to hear Patients in need of their Meds
          cry for help and you hesitate to act, so it good to link them to the
          right source. I hate physical contacts with dealers because i don’t
          know who there are,i prefer ordering online and having it discretely
          overnight delivered to my desired address. Fortunately and glad

          fully for me i found this man Called Dr Mark Donald from where i have
          been ordering now for the past 2 years and he have never failed me in
          any terms of his quality and timely delivery . So i vouch on everyone on
          here to go for him, Contact him via email: /
          Phone number (313) 923-7690

        • jennyjones

          Vapor is only healthy on low Temps and those Temps don’t allow me to get high

    • minusobama

      What about bronchitis?

    • john doe

      It is unhealthy for your asthma you fucking idiot hahaha. Smoking is un healthy period. hahaha damn you fuckers are stupid. how the fuck is inhaling a collection of airborne solid and liquid particulates and gases good for your lungs?

      • dont worry about it

        And do you think living with that negativity Is good for you?
        Really…just rude. Thats no way to talk to a young lady thats just trying to figure it out. Helpful advice rather then insults work just fine thank you.

        • mr smokes

          Dont pay no attention to stupid people like john doe hes just a lost human being that has no life and wants to be heard i respect anyone that does good research on things they want to know.

      • dontbelieve777

        Yeah John can I call you Dick? do the research Dick you’ll find marijuana is excellent for asthma Vap it as well Dick
        have a nice day

      • Bildoe

        You might want to do a little research before you speak. It’s actually been shown to help help asthma in many cases as well as fight/combat lung cancer and tumors. It helps many different cancer patient with nausea as well as curve the appetite for people bodies who reject food during treatments. But thanks for your comment!

      • Joesamoron

        You’re a fucking retard joe

      • xlxTrinityxlx

        you’re a dumbass for assuming you’re correct. There are methods to get high safely, so please stfu.

        • crazyhorse

          exactly xixtrinityxix…polititions have divided this country so badly,,the venomous toxic talk bleeds over into every level of discourse,,,,what a shame people cant just be decent anymore…look we should just ignore the trolls i know its hard sometimes,,but u just dont go anywhere but down with the toxic folks out there….

      • crazyhorse

        typical coward troll,,john doe…right,,if u arent brave enough to leave your name,,then maybe u should go tweet with the donald,,,calling people names,,,pretty imature

      • dontcarewhatothersthink

        Like another just said…MIND YOUR OWN BUSINESS because your language itself shows your ignorance….just sayin…John Doe, you need to smoke a bowl or joint and chill…

      • rook

        John Doe and his followers:)
        let’s start with great comment john doe you are absolutely correct, but incredibly poor delivery.
        i am a 28 yr vet of smoking weed and tobacco
        At age 30ish I started requiring puffers after every flu/cold because my lungs always took longer to recover from illness
        At 35 i quit smoking first weed then two weeks later tobacco because my lungs would struggle to function under the weight of my 110 pound girlfriend at the time (when i needed lungs the most lol)
        after 7 yrs of no smoking my lungs recooprated to only occasional need of puffers
        i have returned to smoking cannabis in the last two months and my lungs have gone to shit :( They struggle at the gym to support muscles with oxygen.) after restarting i have neeedd puffers daily
        last week i bought an expensive vape thumbs crossed this helps or else i have to quit again(:

        • Racist Flying Cop

          Excuse my silly name but your comment has snapped me out of wanting pot.

          • Mark Donald

            Am Mark Donald very grateful for medical marijuana association
            for voting and alleging me as the best helpful Doctor , so for any
            inquiries or help of getting any of your Medical license ,Medicine,weeds
            , seeds, thc/cbd oil , medical marijuana Cards and so on do fast
            to get to me via email address ( ) and contact number (313) 923-7690

          • stefany scolos

            It’s a very sad situation indeed to hear Patients in need of their Meds
            cry for help and you hesitate to act, so it good to link them to the
            right source. I hate physical contacts with dealers because i don’t
            know who there are,i prefer ordering online and having it discretely
            overnight delivered to my desired address. Fortunately and glad

            fully for me i found this man Called Dr Mark Donald from where i have
            been ordering now for the past 2 years and he have never failed me in
            any terms of his quality and timely delivery . So i vouch on everyone on
            here to go for him, Contact him via email: /
            Phone number (313) 923-7690

          • Royal Canadianhotel

            I have been using Dr mark Donald THC/CBD cannabis oil in treating my
            sister’s rare form of left hand side breast cancer with a lot of
            improvement since 3 weeks and the oil is working in a miraculous way
            beyond our expectations. The medication is working with super proof
            though she is always euphoric with THC potency, but the medication is working miraculously. She is a Mother of 3 wonderful kids. i only text
            Dr Mark on his number (313) 923-7690 OR Email address (

    • I was at the Alamo

      You’re not really throwing your life away.

      But you’re still inhaling nasty things when you smoke, regardless of what you burn. You’re still inhaling a lot of products, such as Carbon Monoxide, that won’t really do your lungs any good, even if carcinogens don’t matter.

      And if you do by any chance, get bronchitis, you’re gunna have the most fucking fun in your life with your asthma.

      Also if you’re early 20′s and below, I recommend you to not smoke and have weed at all, it’s not good for your growing body.

      Man if you really want to have weed, you shouldn’t smoke it, I dunno man, vape or drink it in tea, especially with your asthma.

      • crazyhorse

        hey alamo,,,very valid,,,i know from my own experience that smoking pot to early can really impede your growth,,,i started at first in the 8th grade,,,next i lost interest in sports and school in general…i stopped and didnt pick it back up till much later like twenties…so no ones yelling boogie man…but if your planning on college or sports maybe just consider waiting till later,,,

    • mads

      i just did the same thing haha

    • hammerdog

      You’re still a pot head.
      Beware the evil weed – it will rot your brains out!

    • Tina

      I have copd…stage 4. I have smoked marijuana for 40 odd years. I am not able to smoke any longer and would really like to get some good recipes that don’t require a lot of marijuana to make.

      • reptilicus

        Did you get COPD from marijuana or cigarettes?

    • annoyed rabbit

      um they said it’s good for cancer not asthma. Bronchitis seems like it would exacerbate asthma symptoms.

  • Afshin Nejat

    Ah, a negative correlation… either the anti-carcinogenic effects of Cannabis are causally related to this, or else we must assume the average “pot head” simply lives a healthier lifestyle in general, so much so that they are generally less likely to get cancer than the average person who smokes nothing at all. So… when was the last time you saw Joe Joint Puffer living a “healthy lifestyle” per se? The odds are, Cannabis is so anti-carcinogenic that it is not only useful to combat existing cancers in a patient when used in concentrated and frequent dosing regimens, but in fact just regular smokers generally benefit from it!

    Can your cigarette industry lobby make a similar argument for their product? No, but look how legal THAT is. Look at all the DEATH cigarettes and alcohol are directly and indirectly implicated in causing! Yet what do they demonize for decades and decades, even after studies prove that all their lies and rhetoric are just that? They demonize something that people enjoy and which doesn’t make them any money, and in fact cuts INTO their profits with regard to the pseudo-medical farce over which the demonic AMA acts as the ringleader and cheerleader, the liaison between death, dehumanization, illness, and control of people through governmental corruption which answers to oligarchic influence. Cannabis simply cramps their style on all fronts! Especially in that it is beneficial for many, grown out of the ground, and useful for so many things you could BASE AN ECONOMY UPON IT.

    Well, I’d rather admit facts and face reality than be one of the many morons who just need a pat on the back from the Mayor of Pleasantville to feel good about shooting themselves in their heads. They may claim that knowing the truth of matters is silly, crazy, loony, etc, but let’s just remember the kettle and pot, don our imaginary tinfoil hats, and send out a general “FU” to the lemmings who have no respect for reality, but speak of the question of others’ sanity.

    • Pee

      Very well stated!

  • corijean

    I just started smoking Marijuana for pain control. I have never smoked before. I am 44. I have developed a deep cough. I was using a one hitter. Today I tried a hooka. It was a lot more mild. Will this help or cause the cough to get worse.

    • Naynay

      If you’re able to get a vaporizer that will do best I’ve never used Marijuana with a hooka so I’m not sure but the deep cough is just from not letting the smoke cool down before it reaches your throat. If you could use a water piece that helps too!

      That goes away after a while too!

    • hammerdog

      Get the best vaporizer you can afford and dump the one hitter, bongs, and water pipes. The German’s Volcano Vaporizer is still the gold standard I believe.

      • crazyhorse

        i agree with hammerdog,,,i am 54..and smoked in every position and out of every device known to man and the vaporizers are really good…good info hammerdog..

    • jennyjones

      Switch to eating it .it will damage your lungs!

  • gott mit uns

    i smoked cannabis for nearly 17 years after having an x-ray the hospital would not allow me to leave as i had a collapsed lung from the smoking now i had to go have emergency open surgery after having 4 drains inserted with no success but if this does not bother you by all means keep smoking and the surgeons will see you soon enough

    • kooyla

      It sounds like you may have had some other health concerns…this is not normal for a weed smoker.

    • kooyla

      for example, did you smoke cigarettes prior to that, or did you work in dangerous conditions?

    • boblinton

      lol get real man. no one has ever died or had to be rushed into emergency surgery for cannabis use. I don’t even use pot and I know that. If your telling the truth about your lung issues then its not related to or caused by pot there is absolutely no evidence anywhere to support your statements

      • Bildoe

        Actually this is a thing that is associated with smoking pot. You should look into thing before you speak like an ignorant person.

      • jennyjones

        My uncle died from lung cancer from smoking weed. You don’t hear about it because it has been illegal and there are no statistics on it. People will not admit to using it in other words. I am a heavy pot user but I can attest that it certainly causes lung cancer!!!

  • worried for check up

    Hey guys could anyone plz tell me that…can it b known from a xray that if one smokes weed or not?? Or in a chest xray is any spot or any defect seen?i am a regular smoker but i do lots of exercise early in the morning when not high..

  • john doe

    lmao. You have to be fucking retarded to not thing inhaling any kind SMOKE is not bad for you. The safest way to use cannabis is to ingest it. Smokign marijuana is fucjign terrible for your lungs are you people really that stupid? haha

    • Kanishk Varma

      Do you have any medical expertise and experience ?

      • Frank Troici

        He prob is either a 30 year that lives with his parents, a 12-15 year old kid, or someone with no hobby and too much time on his hands. Do research before you type away like a childish troll.

        • Frank Troici

          That was directed toward John Doe

          • crazyhorse

            hey frank,, crazy horse here …your right but we need to ignore feeding trolls the more u say the more he’s gonna irritate us. god bless…hope u have a good day….

    • ripper

      Cannabis is a bronchial dilator you fucking retard meaning it opens up your lungs allowing you to draw in more oxygen making it good for asthma. It has also been proven to increase blood flow through the body.

      • xX420BlazeItGetNoScop’dFagXx

        It’s been proven to give people chronic bronchitis…

      • jennyjones

        My uncle got lung cancer from smoking weed and nothing else. I love weed just as much as the next person but it DOES cause lung cancer as well as lung infections and copd. That being said he smoked it all day everyday. I am sure if you have a joint a day you would be fine.

    • crazyhorse

      hey mister doe for brains any chance u could be a little more respectful,,,calling folks dumb f’s is pretty ignorant really…i have been an outlaw my entire life,,spent an enormous amount of time in max prisons …finally with a personal relationship with god i finally got back on track,,owned 2 houses and 3 successful dog grooming businesses a reformed person…and i promise u if u were to speak to people i know the way u are presenting your comments today…u would get your little teeth knocked out of the back of your head,,,maybe u should scoot on over to rushes twitter and i think you’ll find like minded folks there… i ulick and support should u decide to sed to be an angry person..guess what doe boy…the anger ruined my life and all my friendships …take my advice …start trying to figure out what inside u is so unbearable that u are just stuck on angry..its hard to do,,,dealing with emotional issues seperates the mice from men…god bless u..i wish u good

  • smokem

    I…(cough,cough) can’t… (cough,cough) stop coughing! It’s so good (cough,cough)! Puff,puff to all the haterz, see ya laterz;)

  • LymeKid

    im 16, and i have Lyme disease and severe neurogenic pain disorder. I cannot take pills like endocet, tylenol, oxycodone, because i have a “Non metabolism syndrome that stops the absorption of these pills. ( That means alcohol has no effect on me so i could beat all you guys at a drinking game XD) But anyway, I have to result to the last pain reliever on the planet. Medicinal mariujana. It has changed my life significantly. i can now walk around the block again, and see my grandparents up the street. This article is a fantastic tool to convince skeptics of marijuana consumption. I think Everyone should be pushing for legalization of both Medicinal, Recreational/Religous consumption of mariujana. WE NEED TO FIGHT FOR THIS RIGHT!


    Smoking weed 30 years, I still run marathons… Don’t believe the BS fed to you…

    • jennyjones

      But it depends on how often you smoke. People who smoke many times a day are x a using damage.

  • els2911

    I heard that frequent Marijuana use caused people to have a limited vocabulary and tend to overuse profanity when posting comments on this website. A clear indication of low education and intelligence.

  • stephen dickens

    Addiction does not want to know the truth. And neither do you if your addicted. If you don’t know this, then you have never been addicted, and maybe there is still time to quit before the damage is done.

  • Carmel Maalouf

    how is one joint a day comparable to most tobacco smokers that inhale 1-2 packs a day anyway, you would have to go non filtered cigs to joints on a one to one over time, I don’t see a study that is close to that. smoking is bad news.

  • Todd Hasson

    Well, quit interesting this information. Just wondering when online pharmacies in Europe will sell this like medicines and as an common treatment.

  • Joshua Gavel

    The vaporizor takes about 1/2 an hour to enjoy the equivalent of smoking one joint. A person needs a lot of free time to enjoy it. Rolling one seems like a quick solution. If only vaporizers did their work more quickly… those bags take forever to fill!

  • Jerome Plotnick, Ph.D.

    Marijuana smoking the paper its rolled in contains chemicals and it in a smoke form I believe is hazardous to anyone’s health. The lungs were not made to inhale any smoke or chemicals. But I recommend that if you use it that you can eat it, put it in your salads, etc. Or use the essential oil made from it. Some medical marijuana users vaporize it like a steam. I would have to study that method to make a comment. But again using your lungs for anything other than breathing pure 02 air is not suggested.

  • John Harson

    High Grade Medical Marijuana Sativa and Indica strains, Hash, (RSO),
    BHO, HEMP OILS,THC OILS, Cannabis Oil and Edibles FOR SALE. Text
    (410) 260-0786 Or Email:

  • Mark Donald

    Am Mark Donald very grateful for medical marijuana association authorities
    for voting and alleging me as the best helpful Doctor , so for any
    inquiries or help of getting any of your Medical license ,Medicine,weeds
    , seeds, thc/cbd oil , medical marijuana Cards and so on do fast
    to get to me via email address ( ) and contact number (313) 923-7690

  • jennyjones

    My uncle died from lung cancer he only smoked weed for 40 years. I love weed but it gave him lung cancer