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Thursday, January 31, 2008

All You Pot Smokers Are Going to DIE!!!!!

posted by on January 31 at 13:27 PM

Egads. Is this the green death?

Smoking a joint is equivalent to 20 cigarettes in terms of lung cancer risk, scientists in New Zealand have found, as they warned of an “epidemic” of lung cancers linked to cannabis.

The researchers interviewed 79 lung cancer patients and sought to identify the main risk factors for the disease, such as smoking, family history and occupation. The patients were questioned about alcohol and cannabis consumption.

In this high-exposure group, lung cancer risk rose by 5.7 times for patients who smoked more than a joint a day for 10 years, or two joints a day for 5 years, after adjusting for other variables, including cigarette smoking.

“In the near future we may see an ‘epidemic’ of lung cancers connected with this new carcinogen. And the future risk probably applies to many other countries, where increasing use of cannabis among young adults and adolescents is becoming a major public health problem.”

Scared you’ll be hit by a procession of Hearses carrying hemp caskets? Don’t be. You should be scared of articles like this one.

Of the 79 people with lung cancer studied in New Zealand, the story says, those who smoked more than one joint every day were 5.7 times more likely to have lung cancer than people who didn’t. Those findings are mostly true, for the group of heavy pot smokers.

But, looking at the study, how many people are in that group? Only 14. And how many control subjects are these 14 people compared to? Only four. Extrapolating every marijuana-related lung cancer case from those 14 people is insane. Even more is insane is extrapolating the world population of heavy pot smokers, as the control group, from only four people. You simply can’t draw the conclusion that pot smoking causes cancer at this rate from such a small sample—particularly because more credible studies say it doesn’t.

I’m not a scientist. But obviously, inhaling smoke, including pot smoke, is bad for you and may contribute to cancer. So let’s assume these findings are, in fact, based on credible samples. Is there an impending “epidemic,” as the researchers claim? Well, that would presume the rate of marijuana smoking is increasing. It isn’t; more people smoked pot in the late ‘70s.

If this tiny sample actually related to the entire human race and the pot-smoking-to-cancer relationship existed, millions of wizened hippies would already be laid up in cancer wards. Instead, we have cigarette smokers dying in cancer wards. Which takes us to another problem with the study’s methodology. Several of the pot smokers had also smoked cigarettes.

The scientists say they accounted for "confounding variables including cigarette smoking," but another report, from the same Dr. Beasley, states, “Since a significant number of marijuana smokers also smoke tobacco, future research needs to be directed at investigating the possibility of a synergistic relationship between the two substances.” So pot smokers in this sample who also sucked cigarettes, which are proven to kill people, had undetermined risk factors which may not have been accounted for, in addition heavy dope smoking. If researchers want to accurately gauge the cancer risk for pot, they need to study pot smokers who don’t smoke cigarettes. And, it bears mentioning, most daily pot smokers smoke less than a whole joint.

But here’s the number one reason this study is bullshit: More-credible research completely refutes it. A 2006 report by Dr. Donald Tashkin at UCLA found, “for the hypothesis that marijuana is a risk factor for respiratory tract cancers… there is no epidemiologic evidence for this association.” That study was based on a total of 600 lung-cancer cases (compared to 79) and 1,200 controls (compared to 324). More reports that show marijuana isn’t linked to cancer can be found here, here, and here.

Why doesn't this article mention the study’s flaws and refutations? And why the fuck am I spending 1000 words yammering on about it? Because articles like this one are written by reporters who don’t read the fucking studies, and then it gets spread far and wide. They read press releases about the dangers of drugs and credulously retype them. On the other hand, if the MSM were to get word of a study using only 18 people that shows medical marijuana helps cancer patients, they would shred it.

Here's the rub: lazy reporting turns turns into bad policy. Within the next year, I guarantee that government officials will trot out this article, stamped with the credibility of the mainstream press, as further justification for locking up pot smokers. For example, City Attorney Tom Carr and others used the cancer-from-pot threat as a reason to oppose I-75 in the voters’ guide when he wrote, “Cancer of the respiratory tract and lungs may also be promoted by marijuana smoke, which contains 50 to 70 percent more carcinogens than tobacco smoke.” Carr is right that pot does have more dangerous particulate than cigarettes, but, despite this study, the threat of cancer for the average pot smoker is unproven.

In the end, this study proves three things: 14 pot smokers, including some who smoked cigarettes, got lung cancer (sad, but not indicative of an epidemic). The MSM continues to go gaga over the idea that drugs present an emerging new threat, even when evidence says there isn’t. And, finally, if you’re concerned about the legitimate harms of pot smoke, buy the best pot you can afford and smoke less of it.

RSS icon Comments


This is why I recommend only organic fair-trade BC Bud.

It's the smooth smoke.

Posted by Will in Seattle | January 31, 2008 1:30 PM

That's right: Spin the truth babe spin it real good!!!

Posted by Spin Master | January 31, 2008 1:31 PM

Oh my. Good thing I don't care.

Posted by Mr. Poe | January 31, 2008 1:33 PM

the numbers are small but the risk is real as based on other studies. cannabis burns hotter than tobacco so it can still be equivilant to a couple or more cigarettes. if you smoke it, its still smoking and therefore raises your risk for cancer.

Posted by Jiberish | January 31, 2008 1:36 PM

Typical stoner logic.

Posted by elenchos | January 31, 2008 1:37 PM

Well something's gonna kill me. It might as well be something interesting.

Posted by monkey | January 31, 2008 1:38 PM

Yup, 100% of pot-smokers will die, along with everybody else. But who cares? Pot will remain an outlaw drug in my lifetime and probably a lot longer. Too many powerful forces are aligned to keep it so, even if, compared to alcohol, pot does a lot less damage.

What's really scary is how the same mind set is applied by the media in regards to the products of big pharma. Questionable positive results parroted by the MSM, bad results quashed. And once FDA approved, billions are spent to market products that may be very bad for your long term health.

Posted by Westside forever | January 31, 2008 1:42 PM

I don't smoke pot. I use a vapourizor. (
There's no smoke involved, so much less risk of smoking-related disease. Plus, your pot lasts much longer.

Posted by M | January 31, 2008 1:44 PM

right, inhaling any 'burned' material is not good for your lungs. no doubt. what this ABC article failed to mention (kudos to BBC for at least mentioning it here - is that often people smoke cannabis and tobacco together, making it hard to get useful results from studies like these.

Posted by bongo | January 31, 2008 1:46 PM

Oops. I mis-spelled "vaporizer". I guess there are other risks to smoking pot besides cancer.

Posted by M | January 31, 2008 1:46 PM

Am I the only one who thinks that smoking an entire joint a day isn't a great idea?

Posted by keshmeshi | January 31, 2008 1:47 PM

Make sense to me. My experience is that the weed in Seattle is almost always excellent (seemed about the same as the stuff in Amsterdam), and such a small amount gets the user stoned I just can't imagine it's so bad for you. A tiny fraction of the amount of smoke in one cigarette will get one fairly stoned. My experience is that most people use pipes or bongs rather that joints due to the strength of NW weed.

Posted by PJ | January 31, 2008 1:49 PM

basically all the research and epidemilogical reviews are saying we're not to sure what's going on...we see some possible increases for risk. what IS proven is that its an increased risk for chronic cough, phlegm, and inflamation which can be precursors to lung cancer. what i'm saying is that its no worse than what our current legal drugs but its still not risk free.

Posted by Jiberish | January 31, 2008 1:50 PM

Hmm, you also don't see a lot of cigarette smokers sucking each hit in as deep and hard as they can and holding it there until they crack.

Posted by Fnarf | January 31, 2008 1:54 PM

I agree with you, Jiberish--that smoking pot presents health risks. But the credible evidence shows that the cancer risk, if it exists at all, is a fraction of what this study reports. And there's certainly no impending epidemic.

Posted by Dominic Holden | January 31, 2008 1:56 PM

first: 79 cases, 324 controls. regardless of which categories these people fall into, each person is a unique set of data points, and they all contribute to the results of the analysis.

second: lung cancer has at least a 20-30+ year incubation period. so people smoking dope in the 70s should be getting cancer right about....... now.

third: by including cigarette smoking in the analysis, they control for it's effects on lung cancer. what the results say is that, regardless of cigarette smoking status, sex, income level, and whatever other variables they included, heavy pot smokers have 5.7 X greater risk of lung cancer.

fourth: they DO address the study's limitations. read the discussion: "There are a number of methodological considerations relevant to the interpretation of these findings..." i doubt it would have been published if they did not.

fifth: no single study has all the answers. don't take it too seriously, but don't disregard their findings either. just part of a much larger picture.

Posted by brandon | January 31, 2008 1:57 PM

But, Fnarf, you do see those cigarette smokers dying in the cancer wards...

Posted by Dominic Holden | January 31, 2008 1:58 PM

'Scuse me while I kiss the sky....

Posted by Fifty-Two-Eighty | January 31, 2008 1:58 PM

From the published article:

"...those with the highest tertile of use (>10.5 joint-yrs of exposure) had a significantly increased risk (RR 5.7 (95% CI 1.5–21.6)) after adjustment for age, sex, ethnicity, pack-yrs of cigarette smoking and a family history of lung cancer."

I won't take the time to critique the study but... As JSL notes this is a small sample. The 5.7 figure is a single point estimate and the confidence interval ranges from 1.5 to 21.6. That's pretty darned wide. That it doesn't include the value 1 means that the results are "statistically significant" but it wouldn't be a surprise that the relative risk is as low as 1.5 or as hight as 21.6. As always, the statistician sez you need more data.

Posted by umvue | January 31, 2008 2:01 PM

Hey, I smoke pot but not cigarettes. I'd be happy to sign up for a study, if it give me either free weed or money with which to buy weed...

Posted by Emily | January 31, 2008 2:03 PM

Thanks, Dominic. The link between lazy journalism and bad public policy is a sad story that seems impenetrable to logic. But it never hurts to try.

Posted by Matthew | January 31, 2008 2:04 PM

to be fair there are only 24 people in new zealand

Posted by Bellevue Ave | January 31, 2008 2:06 PM

Of course to really answer the questions about how pot smoking is related to disease we need to employ the gold standard - a randomized controlled clinical trial. Just get all the 12 to xy year olds and randomly assign 'em to treatment (pot smoking) or control. Then just wait and see who gets cancer. Simple.

Posted by umvue | January 31, 2008 2:10 PM

I saw this on the news today and said, duh, smoking anything is bad for you, why is this news? Everyone knows that there are health risks associated with smoking marijuana, it's just that, like with drinking, we accept a degree of risk in doing the things we like.

On a side note... I was having a conversation with some friends the other day about whether THC by itself (absent the smoking) has any long-term harmful effects. Dominic, do you know of any studies about this?

Posted by Julie | January 31, 2008 2:10 PM

In related studies, 100 percent of New Zealanders (or Kiwis as they call themselves) were found to "all gonna die".

The Grim Reaper will hold a press conference just as soon as he finishes inspecting the waterboarding facilities at the secret Homeland Insecurity torture facilities around the world.

Posted by Will in Seattle | January 31, 2008 2:11 PM

2 in the morning, 2 at night, 2 in the afternoon, 2 in times of peace, 2 in times of war, 2 before 2, then 2 more

Posted by w7ngman | January 31, 2008 2:23 PM

Who the Hell still smokes joints in this day-and-age?

And, um, have any of these "rocket scientists" thought of the probability that a lot of the carcinogenic agents found in a typical joint come from the friggin' paper?

Let's see them do a similar study involving pipe/bong/vaporizer/one-hitter usage, and correlate the results with their previous observations. I'll bet those researchers will be surprised by what they find.

Posted by COMTE | January 31, 2008 2:25 PM

My pot-smoking husband was diagnosed and later died of lung cancer, all in his 34th year. He never smoked cigarettes. In discussions with his oncologist regarding cause, we'd mention that he smoked pot - the doc actually shrugged it off. In fact, he still wrote a recommendation for medical mj - only specifying no inhalation of burned materials (so he could eat it, vape it, etc. Some days, it was the only thing that made him feel even slightly better.)

Was pot a factor? Perhaps. The truth of the matter is that ANY cell in the human body has the potential to turn cancerous at ANY time. In ANY of us.

I agree with Dom. The study simply isn't large enough to be representative, and control factors were not clearly defined. Yet the MSM will hype it and shout it from the rooftops - Drugs are bad, mkay?

Posted by Bee | January 31, 2008 2:28 PM

@27 just be careful how you use said pipe/bong...sharing has been shown to increase risk for bronchitis in a study in amsterdam.

Posted by Jiberish | January 31, 2008 2:31 PM

Posted by joan rivers | January 31, 2008 2:50 PM

This is the reason you should EAT pot. Nice long buzz without the nastiness for the lungs.

Posted by bbilly | January 31, 2008 3:00 PM

@11 - an entire joint of the shit I usually get would leave me comatose. Dominic's regular admonition to but Better Pot and smoke less is definitely the way to go, considering the potency of most of the pot I get here in the King/Snohomish County area.

Posted by Hernandez | January 31, 2008 3:53 PM

@31: Agreed. My dad just lost a lung (small cell lung cancer, from smoking 2 packs of cigarettes a day), and I suggested he make himself some pot treats to get his appetite back to normal. It really helped him, he wasn't even able to walk into a grocery store before he tried this.

Personally, eating pot just puts me to sleep, but he loves it. He equated it to a mild mushroom trip.

Posted by Lauren | January 31, 2008 3:55 PM

"I saw this on the news today and said, duh, smoking anything is bad for you, why is this news? Everyone knows that there are health risks associated with smoking marijuana[...]"

That seems to be a common attitude. It just seems intuitively obvious that smoking marijuana MUST lead to an increased risk of airway cancers. And many studies have been done to demonstrate this connection, but they've reported no dependable association between marijuana use and cancers. Looking at all of these studies collectively, it seems that either marijuana does not cause cancers at all or it does so extremely slightly, possibly undetectably so.

Posted by Bison | January 31, 2008 3:56 PM

I think the mercury in all the raw fish I eat will get me first. Oh but I completely forgot that I probably have a greater risk of getting hit in a Seattle crosswalk that'll kill me long before anything else does!

Posted by Anna Montana | January 31, 2008 4:05 PM

Hernandez: Can you hook me up? I'll seek you out at the next Slog mixer.

Posted by Matthew | January 31, 2008 4:16 PM

You sound like all those tobacco-paid scientists. "There's no proven link! Let's not rush to judgment."

Posted by Ed the Head | January 31, 2008 4:36 PM

Ed the Head, you sound silly. Hundreds of thousands of people die from smoking cigarettes. The numbers just aren't there for pot smokers. Sure, pot smoke may cause cancer, but this article claims a joint a day is on par with smoking a pack of cigarettes every day. Are you saying the sample size of this study is adequate or there will be a marijuana-related lung cancer epidemic?

Posted by Dominic Holden | January 31, 2008 5:27 PM

RR of respiratory tract cancer (95% CI)


1st tertile
0.40 (0.12-1.31)

2nd tertile
0.95 (0.38-2.40)

3rd tertile
3.47 (1.13-10.7)

*Adjusted for age, sex, ethnicity and family history and pack-years of tobacco use.

Their numbers are so unbelievably skimpy (it's all "5's and 9's") I don't think it has much power to be able to actually pick up the exposure effect they are looking for. Nine cases and 15 controls in the 2nd tertile, for example! Doesn't stop them from making claims that go far beyond their data. "While our study covers a relatively small group, it shows clearly that long-term cannabis smoking increases lung cancer risk," wrote Beaseley.
It's as if the first part of this sentence has no relation to the second part. Then, Beaseley goes even further and extrapolates to the entire New Zealand population from his 19:5 and 9:15 persons:persons ratios.

Other references to note are:
Cannabis and tobacco smoke are not equally carcinogenic.
Harm Reduction Journal 2005, 2:21

and Tashkin's latest study in Cancer Epidemiology Markers Review....(where they had several THOUSAND subjects--thanks for citing it Dominic!) failed to detect any stat. significant correlations or dose-dependent increase in risk. Then there's the mountain of evidence showing cannabinoids anti-cancer properties...Even a human study out there now! People can't just ignore this data.

I think this has way more to do with the politics around UK cannabis reclassification impending pronouncement by Moore administration than oncology.

Posted by Sunil Aggarwal | January 31, 2008 6:01 PM

A couple comparisons....

A pack of cigarettes has 20 grams of tobacco (approx.), equivalent to 3/4oz. I've never known anyone who who could smoke that much pot in one day, but I've known several three pack a day smokers.

On the other hand, cigs have filters, but also tons of chemical additives that turn into who knows what when burned.

They banned the wrong one.

Posted by drewl | January 31, 2008 7:05 PM

There'll now have to be another study or two to see if the results are reproducible. Remember, if you can't reproduce your results you haven't proven anything.

Posted by NaFun | January 31, 2008 7:15 PM

We remove comments that are off topic, threatening, or commercial in nature, and we do not allow sock-puppetry (impersonating someone else)—or any kind of puppetry, for that matter. We never censor comments based on ideology.

Posted by Mary Jane | January 31, 2008 9:26 PM

@34. Cancer isn't the only health risk to consider when smoking any substance.

Posted by Julie | February 1, 2008 7:42 AM

OMG!!! Smoking is bad for me??? I guess the people studied aren't getting decent weed. If I smoked a whole joint of the stuff I get I'd be curled up under the couch drooling on myself. 2 hits pretty much kicks my ass.

See, this is the benefit to having pot that's supposedly 50 time stronger (or whatever they're saying these days) than the pot of 20 years ago. You smoke less and don't have to worry about cancer as much.

If it was legalized of course Marlboro would start making it and filling it with chemical additives and nicotine.

Posted by Colin | February 1, 2008 12:01 PM

Just vaporize instead of smoke, definitely eases those health concerns

Posted by Farles | February 1, 2008 3:33 PM

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