All Smoke Is Not Created Equal

pot_shopLong-term exposure to tobacco smoke is demonstrably harmful to health. According to the United States Center for Disease Control, tobacco smoking is the leading cause of preventable death in the United States, and chronic exposure to tobacco smoke is linked to increased incidences of cancer as well as vascular disease. Inhaling tobacco smoke is also associated with a variety of adverse pulmonary effects, such as COPD (chronic obstructive pulmonary disease).

Does smoking cannabis pose similar dangers to lung health? According to a number of recent scientific findings, marijuana smoke and tobacco smoke vary considerably in their health effects. So then why are lawmakers in various states, such a Minnesota and New York, imposing new restrictions explicitly prohibiting the inhalation of herbal preparations of cannabis?

Marijuana Smoke vs. Tobacco Smoke

Writing in the Harm Reduction Journal in 2005, noted cannabis researcher Robert Melamede explained that although tobacco smoke and marijuana smoke have some similar chemical properties, the two substances possess different pharmacological activities and are not equally carcinogenic. Specifically, he affirmed that marijuana smoke contains multiple cannabinoids – many of which possess anti-cancer activity – and therefore likely exerts “a protective effect against pro-carcinogens that require activation.” Melamede concluded, “Components of cannabis smoke minimize some carcinogenic pathways whereas tobacco smoke enhances some.”

Marijuana Smoke and Cancer

Consequently, studies have so far failed to identify an association between cannabis smoke exposure and elevated risks of smoking-related cancers, such as cancers of the lung and neck. In fact, the largest case-controlled study ever to investigate the respiratory effects of marijuana smoking reported that cannabis use was not associated with lung-related cancers, even among subjects who reported smoking more than 22,000 joints over their lifetime. Summarizing the study’s findings in The Washington Post, pulmonologist Dr. Donald Tashkin, Professor Emeritus at the David Geffen School of Medicine at UCLA, concluded: “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.”

A meta-analysis of additional case-control studies, published in the International Journal of Cancer in 2014, similarly reported, “Results from our pooled analyses provide little evidence for an increased risk of lung cancer among habitual or long-term cannabis smokers,” while a 2009 Brown University study determined that those who had a history of marijuana smoking possessed a significantly decreased risk of head and neck cancers as compared to those subjects who did not.

Marijuana Smoke and Pulmonary Function

According to a 2015 study conducted at Emory University in Atlanta, the inhalation of cannabis smoke, even over extended periods of time, is not associated with detrimental effects on pulmonary function, such as forced expiratory volume (FEV1) and forced vital capacity (FCV). Assessing marijuana smoke exposure and lung health in a large representative sample of U.S. adults, age 18 to 59, they maintained, “The pattern of marijuana’s effects seems to be distinctly different when compared to that of tobacco use.” Subjects had inhaled the equivalent of one marijuana cigarette per day for 20 years, yet did not experience FEV1 decline or deleterious change in spirometric values of small airways disease.

Marijuana Smoke and COPD

While tobacco smoking is recognized as a major risk factor for the development of COPD – a chronic inflammation of the airways that may ultimately result in premature death – marijuana smoke exposure (absent concurrent tobacco smoke exposure) appears to present little COPD risk. In 2013, McGill University professor and physician Mark Ware wrote in the journal Annals of the American Thoracic Society: “Cannabis smoking does not seem to increase risk of chronic obstructive pulmonary disease or airway cancers… 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.”

Mitigating Marijuana Smoke Exposure

The use of a water-pipe filtration system primarily cools cannabis smoke, which may reduce throat irritation and cough. However, this technology is not particularly efficient at eliminating the potentially toxic byproducts of combustion or other potential lung irritants.

By contrast, vaporization heats herbal cannabis to a point where cannabinoid vapors form, but below the point of combustion – thereby reducing the intake of combustive smoke or other pollutants, such as carbon monoxide and tar. Observational studies show that vaporization allows consumers to experience the rapid onset of effect while avoiding many of the associated respiratory hazards associated with smoking – such as coughing, wheezing, or chronic bronchitis. Clinical trials also report that vaporization results in the delivery of higher plasma concentrations of THC (and likely other cannabinoids) compared to smoked cannabis. As a result, the authors affiliated with the University of California Center for Medicinal Cannabis Research and elsewhere now acknowledge that vaporizers provide a “safe and effective” way to for consumers to inhale herbal cannabis.

The Bottom Line

Based on this scientific record, it makes little sense for lawmakers to impose legislative bans on herbal cannabis products, such as those that presently exist for patients in Minnesota and New York and which are now being proposed in several other states (e.g., Georgia and Pennsylvania). Oral cannabis preparations, such as capsules and edibles, possess delayed onset compared to inhaled herbal cannabis, making these options less suitable for patients desiring rapid symptomatic relief. Further, oral administration of cannabis-infused products is associated with significantly greater bioavailability than is inhalation – resulting in more pronounced variation in drug effect from dose to dose (even in cases where the dose is standardized). These restrictions unnecessarily limit patients’ choices and deny them the ability to obtain rapid relief from whole-plant cannabis in a manner that has long proven to be relatively safe and effective.

23 thoughts

  1. “Cannabis smoking does not seem to increase risk of chronic obstructive pulmonary disease or airway cancers… 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.”

    I think we all lucked out with this result, fellow herbal enthusiasts.

  2. I’d like to know the tally of Democrats and Republicans voting for and against these laws against inhalation of medicine.

  3. I don’t know how many times I’ve heard the phrase “smoke is smoke”, used as an argument to suggest that cannabis is just as bad for one’s health as tobacco, simply because it is a smoked product. Wrong! Now the science is coming in, but a little critical thinking and common sense will tell you that is failed logic. Obviously, what you’re burning matters: you could roll a joint out of old shredded car tires, but it would surely make you sick to smoke it! It matters. Likewise, it’s primarily the tobacco in the cigarette that causes cancer: chewing tobacco isn’t smoked, but it too give you lip cancer.
    Smoke is not Smoke; or, as you say, “Not All Smoke is Created Equal.”

    1. Yes Mark, “Smoke is smoke”, and none of it is equal.

      Are all people created equal? yes and no….depends on if you fear god or love god.

      The example is simple….people are as diverse as cannabis is complex. That’s our main problem, cannabis can’t be understood by looking at it, one has to indulge.

      You and I obviously indulge. Our lifestyles and medical options are controlled by people who are clueless. Should you and I dumb-down or should they smarten-up?

      How can they smarten-up when their lives are ruled by fear of god? The pope says marijuana is evil. duh, ok, I do too, just in case.

      Our struggle remains the same; ignorant bigotry orders law enforcement to harm cannabis believers. I know it sounds too simple-minded but, give it a hard think.

      When we can empower law enforcement to realize that cannabis isn’t the problem that god-fearing dumb-dumbs’ say it is, we’ll all feel better.

      1. Which is more important: Truth, or Faith? If you say “Truth” then I agree with you. If there is a God, and if God also hates lies and loves Truth, then believers should have no trouble separating God’s Truth from Man’s Laws. Cannabis is good; true enough for believers and pagans alike! …if you choose Truth over Faith. (In other words, just because you believe it, doesn’t make it true.)

      2. No doubt…..truth leads and faith follows.

        Why else would we in conflict with prohibitionists?

        I recently made some research on the repeal of alcohol prohibition which required a constitutional amendment. Turns out…faith lost the vote and truth prevailed. Truth is… people like alcohol.

        We have a similar nut-to-crack with our cannabis. Faith votes and truth feels it’s not necessary. Truth isn’t outnumbered the polls reveal. No, it’s that faith follows leaders’ instructions. I call faith, fear, the lack of courage, an excuse to not think, just do what you’re told.

        Our difficulty is educating our fellow humans as to the truth of cannabis despite their faith. Not hardly possible when we study the business of religion and it’s caring for the faithful.

        I hate to say it this way but the war against cannabis continues to be a relic from the early holy wars, the Vatican sees to it.

  4. Marijuana Cuts Lung Cancer Tumor Growth In Half, Study Shows

    Cannabis Kills Cancer

    Dr. Christina Sanchez, a molecular biologist at Compultense University in Madrid, Spain explains how THC kills cancer cells.

    Why CBD Is Not Enough: The Entourage Effect

    Over 100 Scientific Studies Agree: Cannabis Annihilates Cancer

  5. Is this “per year” a typo that should have been ‘per day’? If not, one marijuana cigarette a YEAR for 20 years sounds like a ridiculous criteria to use to evaluate lung damage.

    The article said:
    “Subjects had inhaled the equivalent of one marijuana cigarette per year for 20 years, yet did not experience FEV1 decline or deleterious change in spirometric values of small airways disease. – See more at:

    [Paul Armentano responds: Yes, it is a typo. It should say ‘per day.’ The correction has been made.]

  6. What an amazing plant. When I think of all the lies we’ve been told by our government for so many years it makes my blood boil. And we still have idiots trying to spin their deceitful webs. Like Kevin Sabet and that Kennedy jerk. What’s it to them if people safely consume cannabis in their own home?

    1. They represent the antique Puritan mindset that shudders at the thought that someone somewhere is enjoying themself.

      1. Kevin Sabet has indicated he considers the Big Tobacco thing to have been a disaster, and o.k. he fears a similar thing with a Big Marijuana. His idea will make sense once we agree that

        (a) a 700-mg HBOM Combustion $igarette is Big Tobackgo, and

        (b) a 500-mg Joint or nicotinfested Blunt is Big Marijuana, and

        (c) in order to guarantee that only a Little Marijuana will be permitted, instigate the sudden mass manufacture of billions of $1.29 DIY fdt-1-hitters (dosage-regulating 25-mg-$erving-$ize $ingle Vape Toke Uten$il), so that

        d. Instructive cartoon posters (such as “More Marley Less Monoxide” showing Bob demonstrating a fdt1h) will teach Easy-Learn VAPE-not-Burn Toke-Technique. $igarettes will vanish from the planet, 6-million “smoking” deaths/year figure will shrink to zero in a decade, NORML will win Know-it-well Prize $1.5mil, and tobackgo farmers will be re-educated into providing future forestry with several years/billions of acres of cannabis crops (Cannabis is premier precursor crop for TREES/”truth”; each Finger is one FIFTH/”faith” of a Hand (human organ cannabis was named after).

        e. The old billion dollar $igarette rolling machines will instead roll “brownspliff”– cheap biodegradable brown hemp paper with POTting soil inside, plus one or more SEEDS, to be planted in dibblestickholes, high sprout and root potential.

  7. Thank you America for leading the way in drug policy based on science instead of fear! God bless America! USA! USA! USA!

    1. America is hardly leading the way in terms of reasonable and long-needed drug policy. We’re actually behind some. For example, a Canadian news segment had smugly pointed out after Colorado’s legal recreational started: “Even though the Netherlands has been enjoying pot lounges for decades now, Colorado has now legalized recreational!” That’s a paraphrase of the news report as it was awhile ago that I heard it, but the point still stands. And the Netherlands isn’t the only enlightened one to have changed their tune already, unlike here in America, where people can still be jailed or have their children taken away or remain in jail for marijuana offenses in even legal/medical states.

  8. These facts, and other pro-legalization arguments, are the things that need the drumbeat. They’re the kinds of things the New York Times, CNN, MSNBC, and other major news organizations need to keep the drumbeat going on about. What the hell happened to the NYT’s drumbeat on this? MSNBC and CNN just give up? It seems whenever there is something about pot legalization on my local news it’s nearly always dead last to keep viewers on that tv channel, you know, so they don’t switch channels. They keep the viewer number$ they’re $elling to their advertiser$.

    Let’s go NYT, CNN, MSNBC and everybody else! Keep up that drumbeat!

  9. I live in Minnesota. I am disabled by severe Fibromyalgia, Myofacial disorder, and degenerative arthritis. The primary method of buying cannabis in this small town is through people much younger than myself.
    As I don’t get out much, and don’t socialize with teenagers- So, I don’t have access. I live in an apartment, so it’s not like I can grow it myself.
    So, I approached my Dr. Big mistake! He insists that Dr’s that prescribe cannabis will eventually lose their license to practice…
    Then, he had me sign a foolish form. It basically states that, in order to continue receiving prescription pain meds , that I will not use illegal/’street drugs’. At this point, I am stuck taking Rx pain meds just to function.
    That, in itself is a challenge, as they make me so groggy.
    Can anyone help me find access to safe, and reasonably priced, cannabis for pain treatment?

  10. “Long-term exposure to tobacco smoke is demonstrably harmful to health. CDC: tobacco smoking is the leading cause of preventable death in the United States.”

    NORML here chooses a good time to start the aftermath of pretty likely 2016 victory– after legalization, proceed with reform!

    Acronym WORKVIU on cartoon posters everywhere showing Marley demonstrating the drawtubeonehitter: Worldwide Organization for the Reform of Kannabis Inhalation Utensils.

    The three legs of reform:

    1. Replace tobacco with 1/16″-sifted cannabis bud, or other non-tobacco herb including alfalfa, basil, buchu, chamomile, catnip, damiana, dandelion, eucalyptus, fennel, fo-ti-tieng, ginseng leaf, hops flower etc. See Wikiversity “Smoking Cessation: Herbal Alternatives”.

    2. Substitute 25-mg serving size for 700-mg $igarette, 500-mg Joint, it’s Cheaper Than You Think with a flex draw tube vape toke pipe made from a pre-shaped #40screen and $1.29 worth of parts lying around in your garage, see wikiHow: “12 Easy Ways to Make a Flex Draw Tube Vape Toke Pipe”. Or if you have the $$ money buy the Volcano.

    3. Substitute VAPE for $moke with this easy-learn vape-toke technique: hold 25-mg-i.d. screened craterhead far enough from your eyes to see what you’re doing, suck slow steady through the flexhose, hold cheapo Chinese half-inch lighter flame tip an inch below the opening, so optimally air will enter at 385F/197C vaping temperature. If a tiny bit of herb catches on fire, hold lighter 10% further away. If herb darkens, good. After nutrient is vaped out you might want to Taste the cellulose aglow. Move maintenance pin around gently between lightings, suck and taste all ashes, good otherwise missed minerals.

    “Hold light low,
    Suck slow,
    Don’t Glow
    Till after 19
    Seconds or So.”

  11. If we can tell the difference
    Between grape juice and wine
    Why is it so hard
    To tell tobacco smoke from mine?

    I thought the smell was obvious
    Tobaccos toxic; weed is not
    This aint Europe, we don’t mix’em
    So stop takin what I got

    Vaporizers are all good
    And friendly for weed’s indoor use
    But smokin it like our ancestors
    Don’t seem like drug abuse

    It seems like smokey definitions
    Keep cannabis from regulation
    When the entire scheduling system
    Is an unjust violation

    Tobacco kills half a million
    Americans each year
    N’weed? the CDC has yet to find
    A single death to fear

    So how is it mari-huana
    Is Still on schedule 1?
    When tobacco aint even on the list
    And it’s killin everyone?

    NIDA stopped the science
    The DEA pulled most the hemp
    Decades of tax reliance
    And they still aren’t truth-exempt

    They jailed us and they killed us
    In the name of the drug war
    They separated families
    Makin profit off the poor

    When Jesus was imprisoned
    Wrongfully as fear loathes
    His followers had asked him
    “When did we bring you clothes?

    Or food when you were sick?”
    And the Lord said unto thee
    “Even the least of which you did
    For them, you did for me”

    So here I sit and ponder
    As a NORML consumer will
    How many legal buds must sell
    To stop the blood we spill?

    And the answer flows within me
    Our endocannabinoids
    Are all rooted together
    In a place where greed avoids

    Where the herb and human history
    First had coevolved
    Lies the truth and mystery
    That love and justice solved

    Tell your neighbor
    Tell your Congressman
    Upon the highest mountain
    For peace and education
    Cannabis provides the fountain
    For shelter, food and medicine
    For fuel, for clothes and song
    If scheduled drugs aint right
    Than descheduling them aint wrong
    Then let the states legalize
    And regulate their rules
    And lets stop building prisons
    And turn the profit into schools

  12. It was either that or;

    “Up in smoke
    That’s where my tax money goes
    Prohibiiiiition puts a criminal
    In cops clothes

    And smoke’s Leeeeegal defintion
    Nobody knows
    So I take a toke
    But I aint broke
    Just up in smoke…”

  13. Now a day, smoking has much effect on your body. Many long time use tobacco is very dangerous. No doubt the tobacco is used in every smoking and fuddle. You can also compare with Marijuana. So please stop the smoking in your life.

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