Growing evidence of marijuana smoke's potential dangers

August 5, 2009,
Smoking marijuana causes more damage to cells and DNA than smoking tobacco, scientists say. Credit: Wikimedia Commons

In a finding that challenges the increasingly popular belief that smoking marijuana is less harmful to health than smoking tobacco, researchers in Canada are reporting that smoking marijuana, like smoking tobacco, has toxic effects on cells. Their study is scheduled for the Aug. 17 issue of ACS' Chemical Research in Toxicology.

Rebecca Maertens and colleagues note that people often view marijuana as a "natural" product and less harmful than tobacco. As public attitudes toward marijuana change and legal restrictions ease in some countries, use of marijuana is increasing. Scientists know that marijuana smoke has adverse effects on the lungs. However, there is little knowledge about marijuana's potential to cause lung cancer due to the difficulty in identifying and studying people who have smoked only marijuana.

The new study begins to address that question by comparing marijuana smoke vs. tobacco smoke in terms of toxicity to cells and to DNA. Scientists exposed cultured animal cells and bacteria to condensed smoke samples from both marijuana and tobacco. There were distinct differences in the degree and type of toxicity elicited by marijuana and . Marijuana smoke caused significantly more damage to cells and DNA than tobacco smoke, the researchers note. However, tobacco smoke caused chromosome damage while marijuana did not.

More information: "The Genotoxicity of Mainstream and Sidestream and Condensates", Chemical Research in Toxicology

Source: American Chemical Society (news : web)

Explore further: Marijuana smoke contains higher levels of certain toxins than tobacco smoke

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5 / 5 (7) Aug 05, 2009
smoking any plant material is harmful but but active chemical, THC, the main ingredient outlawed has shown almost negative side effects. You can ingest it, vape it, possibly inject it but no the government says no so we must subject our lungs to smoke. Legalize
5 / 5 (4) Aug 05, 2009
the government says no so we must subject our lungs to smoke

The legal status of reefer has nothing to do with you "having" to smoke it, like you said, you could just buy a vaporizer (convective not conductive), which have legal uses and are completely legal to sell and buy...

Or if you have any electrical engineering capabilities they're not super complicated to build, unless you want temp control...

But yea, we gotta overcome Big Pharmacy before pot will ever be legal.
5 / 5 (7) Aug 05, 2009
Research until the desired results are achieved!
5 / 5 (9) Aug 05, 2009
Another bullshit laboratory propaganda "study."

Try doing an Internet search on Donald Tashkin.

"We know that there are as many or more carcinogens and co-carcinogens in marijuana smoke as in cigarettes,%u201D researcher Donald Tashkin, MD, of UCLA's David Geffen School of Medicine tells WebMD. "But we did not find any evidence for an increase in cancer risk for even heavy marijuana smoking."

... In a review of the research published last fall, University of Colorado molecular biologist Robert Melamede, PhD, concluded that the THC in cannabis seems to lessen the tumor-promoting properties of marijuana smoke.

The nicotine in tobacco has been shown to inhibit the destruction of cancer-causing cells, Melamede tells WebMD. THC does not appear to do this and may even do the opposite.

While tens of millions of Americans smoke pot regularly, cannabis has never caused a known case of lung cancer as of December 1997, according to America's foremost lung expert, Dr. Donald Tashkin of UCLA.
Cannabis is a complex, highly evolved plant. There are some 400 compounds in its smoke. Of these, 60 are presently known to have therapeutic value.

Cannabis may also be eaten, entirely avoiding the irritating effects of smoke. However, four times more of the active ingredients of smoked cannabis are absorbed by the human body than when the same amount is eaten. And the prohibition inflated price of black market cannabis, combined with harsh penalties for cultivation, prevent most persons from being able to afford the luxury of a less efficient, though healthier, means of ingestion.

Lab Studies Fail to Reflect the Real World.

Studies have proven that many of the carcinogens in cannabis can be removed by using a water pipe system. Our government omitted this information and its significance when speaking to the press. At the same time politicians outlawed the sale of water pipes, labeling them "drug paraphernalia." ...

Donald Tashkin of the UCLA David Geffen School of Medicine, Division of Pulmonary and Critical Care Medicine, said: "[A]t this point, I'd be in favor of (marijuana) legalization. I wouldn't encourage anybody to smoke any substances. But I don't think it should be stigmatized as an illegal substance. Tobacco smoking causes far more harm. And in terms of an intoxicant, alcohol causes far more harm (than marijuana)."

Tashkin said that when he began his work thirty years ago, he "opposed ... legalization because [he] thought it would lead to increased use and that would lead to increased health effects." However, he now admits that his decades' worth of scientific research revealed an opposite conclusion.

I will repeat that, personally, I HATE smoking.

Smoking is the worst way to consume cannabis.

I like vapourizers, which are three times more efficient, & far, far more healthy than any smoking of marijuana.

I like to eat marijuana baking,
but that tends to be expensive.

People who chew tobacco still get cancer.

People who eat cannabis NEVER get cancer from that.

In my opinion the single worst thing about smoking anything is carbon monoxide poisoning, affecting the blood stream ...

However, the bottom line is that our whole civilization is controlled by huge lies, backed by lots of violence.

The mass media are major players in maintaining that.

Even IF marijuana was dangerous, criminalizing it more will actually only increase the real harms.

The purpose behind the pot prohibition
is to have a tool of persecution which
can be used as an excuse to build a
fascist police state to become bigger.

So-called "science" like this feed that.
1 / 5 (2) Aug 05, 2009
Oxidation of anything has always proven to be unhealthy, however i wonder about the nuclear oxidation of hydrogen.

Plz vaporize, eat, snort, topical tincture the ingestion of neurochemicals.
5 / 5 (3) Aug 06, 2009
There is a reason why they try to mimic THC as medical substance but don't allow the real thing.
You can't charge people money for medizin which grows in illigal and sell some more or less alike chemical substance.
Someone should take a look who funded this study :)
1 / 5 (4) Aug 06, 2009
I just saw a recent special on National Geographic entitled Drugs. They showed a native group that smoked marijuana very heavily and they had lung infections, breating problems, etc. The problems affected the group 10years AFTER they began to smoke.
3 / 5 (3) Aug 06, 2009
there is never middle ground argument in this...only its bad ..or its not...

...both very wrong....weed is better than smoking cigarettes, not necessarily raw tobacco.

Cigs have 100s of added chemicals ...weed doesnt...

A joint is mostly a mix of weed and tobacco from a cig...therefore if lung cancer appears, one group will say its the weed and other will say its the cigs.

Weed cant be taxed as efficiently as tobacco cus I ca grow it in a pot on my window... Tobacco require industrial size land....(i 93year old, 80 yr smokin grandad always smoked his own)
5 / 5 (6) Aug 06, 2009
All smoke is harmful the primary difference between marijuana and tobacco is that tobacco users expose themselves to much more smoke then marijuana users.

In general everything has potential dangers, even water, it all comes down to dose. Without such information this article is just a worthless piece of propaganda.
1 / 5 (5) Aug 06, 2009
simple logic:
weed grows everywhere, toxic smoke is given off when it is smoked, it has toxic effects when smoked. Weeds are a nuissance to house living and most people want to get rid of weeds, why make it legal to the public when every tom dick and harry will be growing it on everyone else's property?
not rated yet Aug 06, 2009
"However, there is little knowledge about marijuana's potential to cause lung cancer due to the difficulty in identifying and studying people who have smoked only marijuana."

They are neglecting to mention the fact that the body can break down the resin/tar that is put into our lungs by marijuana naturally over a not very long time period (cant remember exactly how long off the top of my head).

The predominance of harmful materials from mary would come from a joint, and that harmfulness comes from the paper used, not from the smoke itself.

it does make sense for some cell or dna damage to occur though, as we do not breathe smoke in our natural state...smoke leads to death by smoke inhalation at high it seems common sense to me that some damage would be caused by smoking anything....

I agree with whoever, and who all, above said this is just more propaganda, this time coming from a "partner" country of the US government (whom I'm sure our government gives hell all the time about being so relaxed on the weedies)...all this is, is that some US firm paid a freakin canadian firm to give the bullshit so its coming from some place new :)

if i understoiod you correctly, your argument is, well frankly, not very good...
First: that is not simple logic, if you look at Texas for instance, there are a large number of people whom prefer natural landscaping vs. a golf green for a yard. i will admit i myself am NOT one of those, and I think what's the point in having a fkn field for a yard, but, its alot of folks in this state...
Second: there is a big difference between dandelions and prickly patches and marijuana my friend.....also, very few people would grow outdoors in their yards when you can get faster and better results indoors....
5 / 5 (5) Aug 06, 2009
Has anyone noticed that you smoke far less material when you smoke marijuana vs tobacco? The amount consumed even by heavy smokers must be well under what would be a fourth of a pack of cigarettes.

In other words, this study is stupid.
5 / 5 (4) Aug 06, 2009
..and then again.. Even if a weed is dangerous and causes the cancer, which I think does not, the cigarettes on the other hand are causing the cancer, and that is a proven fact, but they are legal anyway. The main argument is, that a weed leads to the more addictive drugs, but I think it's only caused by weed's illegality status. You're forced to buy from shady dealers and one day they can simply try to offer you something 'better'. You already know that society lied to you about the weed being dangerous (addictive), so you figure, that society lied about those other ones too. You'll find out too late.
1 / 5 (1) Aug 06, 2009
Has anyone noticed that you smoke far less material when you smoke marijuana vs tobacco? The amount consumed even by heavy smokers must be well under what would be a fourth of a pack of cigarettes. I agree, and would say on average it is MUCH less than that. Many pot smokers choose the stronger versions anyway, requiring even less volume. FAR less volume. the 'average' cig smoker vs the 'average' pot smoker would, I would guess be like 1/50 the volume or less. I say that because the 'average' pot smoker is not even doing it daily. And the 'heaviest' regular pot smoker would not even be as much volume as the 'lightest' regular cig smoker. failing to account for that shows the 'study' is a bunch of crap.

In other words, this study is stupid.

1 / 5 (1) Aug 06, 2009
Here is the schedule for national geographic channel
taboo: drugs and Explorer:marijuana nation
1 / 5 (1) Aug 09, 2009
since this is top page once more I will make one last comment about; think about it when you decide to bring in a non-native plant into an area, you are acting like the wind; where is most of the severe weather in the world?
5 / 5 (1) Aug 09, 2009
I remember a study of LSD that said that it damaged mouse brains. Buried in the research paper was the fact the the mouse brains had been centrifuged.

No study of this type is reliable without carefully combing through the details. Was the -density- of the MJ smoke the same as the cig's? etc. etc. There's 4000 ways of constructing tribal lays when it comes to politicized results.
not rated yet Aug 10, 2009
Prior to any consideration of legalization, research needs to assign some value for a level of intoxication, and a new subset of laws. From Prem Shukla, MD in UpToDate: "Through its effects on coordination and cognition, marijuana intoxication contributes to injuries and accidental deaths in adolescents, particularly for motor vehicle crashes. The use of marijuana has been implicated in as many as 11-33% of fatal accidents among 15-30-year-olds.( 1,2)" 1. Brookoff, D, Cook, CS, Williams, C, Mann, CS. Testing reckless drivers for cocaine and marijuana. N Engl J Med 1994; 331:518.
2. Sutton, LR. The effects of alcohol, marihuana and their combination on driving ability. J Stud Alcohol 1983; 44:438.

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