One of the big claims of the prohibitionists has always been that cannabis causes cancer, indeed that smoking cannabis is worse than tobacco, it seems this isn’t quite true despite all the doom laden claims made over the years! For example back in 2002 the British Lung Foundation published a report called “A Smoking Gun” which suggested:
The British Lung Foundation recommends a public health education campaign aimed at young people to ensure that they are fully aware of the increased risk of pulmonary infections and respiratory cancers associated with cannabis smoking.
Worse
The increased potency of the cannabis smoked today compared to the cannabis smoked twenty-thirty years ago suggests that earlier studies may underestimate the effects of cannabis smoking.
And that
It has been calculated that smoking 3-4 cannabis cigarettes a day is associated with the same evidence of acute and chronic bronchitis and the same degree of damage to the bronchial mucosa as 20 or more tobacco cigarettes a day
Interestingly the reference given to that link is to one Prof Ashton – one of the “usual suspect” in the cannabis debate. If you follow the reference given in “A smoking gun”it takes you to Prof Ashton’s paper you will see she writes:
It has been estimated that smoking a cannabiscigarette results in approximately a five-fold greater increasein carboxyhaemoglobin concentration, a three-fold greater amountof tar inhaled and retention in the respiratory tract of one-thirdmore tar than smoking a tobacco cigarette
And so you can follow other references which quote other studies which claim to have estimated all sorts of things about the cancer causing nature of cannabis – all made worse of course by the increase in THC content in recent years (skunk…)
The average cannabis cigarette smoked in the 1960s contained about 10mg of tetrahydrocanabinol (THC), … compared to 150mg of THC today.
The claim being of course that THC was a cancer causing substance. Of course, this rubbish got a lot of non-critical publicity at the time, dire warnings to cannabis users and worried parents make good news stories apparently. The BBC ran a story headed ‘My lungs are damaged beyond repair’ in 2007 (here) which claimed
Dr Kon said he had several other young patients who smoke cannabis and have lung diseases normally seen only in older tobacco smokers.
So the idea that smoking cannabis causes cancer is a well established fact if you believe the British media – and that’s without mentioning the Daily Mail! The problem with this “well established fact” is, well, it isn’t. Actually it’s not only not a well established fact, it’s actually not true – with one big exception which is utterly avoidable.
A paper published recently entitled “Cannabis and tobacco smoke are not equally carcinogenic” by Robert Melamede of the University of Colorado in Colorado Springs, USA. The abstract is pithy and to the point:
More people are using the cannabis plant as modern basic and clinical science reaffirms and extends its medicinal uses. Concomitantly, concern and opposition to smoked medicine has occurred, in part due to the known carcinogenic consequences of smoking tobacco. Are these reactions justified? While chemically very similar, there are fundamental differences in the pharmacological properties between cannabis and tobacco smoke. Cannabis smoke contains cannabinoids whereas tobacco smoke contains nicotine. Available scientific data, that examines the carcinogenic properties of inhaling smoke and its biological consequences, suggests reasons why tobacco smoke, but not cannabis smoke, may result in lung cancer.
it notes
Tobacco has dramatic negative consequences for those who smoke it. In addition to its high addiction potential, tobacco is causally associated with over 400,000 deaths yearly in the United States, and has a significant negative effect on health in general. More specifically, over 140,000 lung-related deaths in 2001 were attributed to tobacco smoke. Comparable consequences would naturally be expected from cannabis smoking since the burning of plant material in the form of cigarettes generates a large variety of compounds that possess numerous biological activities.
While cannabis smoke has been implicated in respiratory dysfunction, including the conversion of respiratory cells to what appears to be a pre-cancerous state, it has not been causally linked with tobacco related cancers such as lung, colon or rectal cancers. Recently, Hashibe et al carried out an epidemiological analysis of marijuana smoking and cancer. A connection between marijuana smoking and lung or colorectal cancer was not observed. These conclusions are reinforced by the recent work of Tashkin and coworkers who were unable to demonstrate a cannabis smoke and lung cancer link, despite clearly demonstrating cannabis smoke-induced cellular damage.
This is quite clearly the “wrong” result for the prohibition lobby, yet another wrong result! There are many aspects to this of course, smoking anything involves breathing in irritants and goo which deposits in the lungs, but along with the apparent ability of THC to actually kill cancers it seems tobacco is actually a cause of the disease in its own right
The need to better understand the biological consequences of tobacco compared to cannabis smoke has been underscored by recent studies that demonstrate a unique role for nicotine in the pathogenesis of lung cancer
So far from cannabis smoking being four times worse than tobacco, the opposite is true – only not by just a factor of four!
In conclusion, while both tobacco and cannabis smoke have similar properties chemically, their pharmacological activities differ greatly. Components of cannabis smoke minimize some carcinogenic pathways whereas tobacco smoke enhances some.
So although smoking cannabis may possibly lead so serious lung damage over the long term due to the irritant nature of the smoke and other effects
… current knowledge does not suggest that cannabis smoke will have a carcinogenic potential comparable to that resulting from exposure to tobacco smoke.
The paper end with this potent thought:
It should be noted that with the development of vaporizers, that use the respiratory route for the delivery of carcinogen-free cannabis vapors, the carcinogenic potential of smoked cannabis has been largely eliminated.
So the cancer threat so heavily promoted by the prohibition supporting press is just hype then?
Well, yes but no. There is a huge, juicy fly in the ointment as far as UK tokers are concerned. It’s an issue this site bangs on about time and time again because it is so, so important. British cannabis users smoke tobacco filled joints. There really shouldn’t be any debate over the need for a safer use campaign aimed at cannabis users now. Unlike the hype pushed by the British Lung Foundation in 2002, this and other research has had precisely zero coverage in the media, but that’s to be expected. However the powers that be know the real situation even if the public are treated like mushrooms (kept in the dark and fed bulls**t). They know that tobacco is the biggest health risk faced by cannabis users, it’s time they did something about it.
We need Tokepure – or something like it urgently.
Even with Tobacco I wonder how much of the harm is caused by the chemicals and other nasty things added in the commercial production process rather than the plant itself.
Maybe we are touching on one of the real fears that big business has about cannabis. In short it has been shown that THC kills cancer cells – google this. I recall seeing a medical study that showed cannabis smoke (without tobacco) actually causes more pre-cancerous lesions in the lungs than tobacco smoke but these lesions do not tend to develop into tumours. Of course no one ever thinks to investigate this effect with relation to curing cancer – that is not scientific is it ? – so the conclusion was that cannabis smoke was more carcinogenic than tobacco smoke simply because of the higher number of lesions in the lungs !
I agree that it is reasonable to claim that ‘3 – 4 cannabis cigarettes’ a day is associated with the same health risks as 20 tobacco cigarettes because for most users (in the UK at least) a ‘cannabis cigarette’ is just that – a cigarette with some cannabis in it. As is said above cigarette tobacco is especially dangerous when smoked without the filter it is designed to work with and rolling tobacco is not much better. The publicity and hype never makes the distinction between cannabis, cannabis smoke and cannabis/tobacco mixtures. So one side claims that cannabis is relatively harmless (eg pure THC injected into mice under laboratory conditions) and the other side that it is very dangerous to health (smoking cannabis of uncertain quality in a tobacco mixture with no filter). They are both right but they are not talking about the same substance or means of ingestion.
Best not to smoke tobacco with cannabis even better not to smoke it at all – drink it , eat it , vaporise it. Once again ignorance and prohibition causes the harm not cannabis.
It is impossible to say whether the chemicals used in cannabis’ illegal production cause much harm. Most growers ‘flush’ crops (remove fertilizer build up by watering with just water in the last few weeks of flowering) if they don’t it tastes really bad. The only other possibility is if pesticides are used in late flowering (or worse still during drying) this could pass on residues. Without regulation we simply don’t know what is going on or what we are buying.
I have to say I smoke cannabis/tobacco mixtures, rolling tobacco, can’t stand fags crumbled into a spliff. The main reason is it just makes the green go further. Can’t afford to pay prohibition inflated prices and smoke pure blunts
Sam wrote
It’s amazing how often you hear tokers say that, but it’s simply not true Sam.
If you were to quit tobacco, I’ll bet you use less green, not more. The reason being you’re not smoking to satisfy a tobacco craving, which a hell of a lot of cannabis tokers do. Most if not all tokers I know who quit tobacco found they used getting on half the amount of cannabis as a result.
Quitting tobacco saves you money because you smoke less weed and you don’t have to buy the tobacco.
I could probably get 2 or 3 joints out an eighth if I didn’t use tobacco I think. I like how long it takes to smoke one, I like that it’s social and can be passed around, but I do understand where you’re coming from. It’s also handy when you’re out and about, having everything you need in one pocket.
But I digress, the main point is the paper showing that cannabis seems to inhibit cancerous growths rather than encourage them. The pile of evidence can only get higher…
but will it ever be high enough…..
Using a vaporizer actually reduces the amount of weed I use by about a third as against using a pipe. Why people smoke spliffs with tobacco is beyond me. Pass the cancer stick round will you puff puff pass…
Sam mentioned 2 or 3 joints out of an eighth– i.e. that means rolling almost a gram each time?? Gone in a few minutes?? Compare to a 25-mg. serving-size one-hitter, that’s 40 single tokes per gram. (And if you use a one-hitter you’ll just “forget” to mix in the tobackgo.)
The use-it-up-in-a-hurry psychosis is doubtless due to the law enforcement dilemma, fearing to having any herb left over for spies and narcs to catch you with, let alone a rational dosage-management utensil. THINK! Isn’t it mausetot obvious that this is a result of the tobackgo corporations manipulating the government through their monstrous tax “contributions”?
P.S. Excuse me, previous hour on safe anonymous library computer ran out.
1. John Moore: you are right, since about 1913 (introduction of “Camel” brand) they have been adding drugs to suppress the coughing reflex and make the smoke “feel” milder, fooling the users into thinking that giant $igarette-size overdoses aren’t dangerous.
2. Sam: the “social” element of passing a joint around is replaced by using a one-hitter with two (2) long flexible stems. Put in the same 25-mg. serving of sifted herb as for a single toke; each partner draws twice as slow, getting half the heat, so it’s more mild; to get the same amount of THC serve twice as many tokes. After each toke, a huge intimacy can be achieved though various kinds of “shot-gun” precedure which unfortunately some asshole deleted from the Wikipedia Cannabis Smoking article but you can guess what is meant. “Voi sapete, quel que fa.”
another study on the effects of THC on cancer cell growth but still no one wants to study this effect
http://blog.norml.org/2010/08/04/cannabis-once-again-shown-to-halt-cancer-growth-so-why-arent-we-studying-it-in-humans/
how long before the next blog entry?