Posted on 08/23/2005 5:14:08 AM PDT by Wolfie
Study: Smoking Marijuana Does Not Cause Lung Cancer
Protective Effect "Not Unreasonable"
Marijuana smoking -"even heavy longterm use"- does not cause cancer of the lung, upper airways, or esophagus, Donald Tashkin reported at this year's meeting of the International Cannabinoid Research Society. Coming from Tashkin, this conclusion had extra significance for the assembled drug-company and university-based scientists ( most of whom get funding from the U.S. National Institute on Drug Abuse ). Over the years, Tashkin's lab at UCLA has produced irrefutable evidence of the damage that marijuana smoke wreaks on bronchial tissue. With NIDA's support, Tashkin and colleagues have identified the potent carcinogens in marijuana smoke, biopsied and made photomicrographs of pre-malignant cells, and studied the molecular changes occurring within them. It is Tashkin's research that the Drug Czar's office cites in ads linking marijuana to lung cancer. Tashkin himself has long believed in a causal relationship, despite a study in which Stephen Sidney examined the files of 64,000 Kaiser patients and found that marijuana users didn't develop lung cancer at a higher rate or die earlier than non-users. Of five smaller studies on the question, only two - -involving a total of about 300 patients-concluded that marijuana smoking causes lung cancer. Tashkin decided to settle the question by conducting a large, population-based, case-controlled study. "Our major hypothesis," he told the ICRS, "was that heavy, longterm use of marijuana will increase the risk of lung and upper-airways cancers."
The Los Angeles County Cancer Surveillance program provided Tashkin's team with the names of 1,209 L.A. residents aged 59 or younger with cancer ( 611 lung, 403 oral/pharyngeal, 90 laryngeal, 108 esophageal ). Interviewers collected extensive lifetime histories of marijuana, tobacco, alcohol and other drug use, and data on diet, occupational exposures, family history of cancer, and various "socio-demographic factors." Exposure to marijuana was measured in joint years ( joints per day x years that number smoked ). Controls were found based on age, gender and neighborhood. Among them, 46% had never used marijuana, 31% had used for less than one joint year, 12% had used for 1-10 j-yrs, 5% had used 10-30 j-yrs, 2% had used for 30-60 j-yrs, and 3% had used for more than 60 j-yrs.
Tashkin controlled for tobacco use and calculated the relative risk of marijuana use resulting in lung and upper airways cancers. A relative risk ratio of .72 means that for every 100 non-users who get lung cancer, only 72 people who smoke get lung cancer. All the odds ratios in Tashkin's study turned out to be less than one! Compared with subjects who had used less than one joint year, the estimated odds ratios for lung cancer were .78 for 1-10 j-yrs [according to the abstract book and .66 according to notes from the talk] .74 for 10-30 j-yrs; .85 for 30-60 j-yrs; and 0.81 for more than 60 j-yrs. The estimated odds ratios for oral/pharyngeal cancers were 0.92 for 1-10 j-yrs; 0.89 for 10-30 j-yrs; 0.81 for 30-60 j-yrs; and 1.0 for more than 60 j-yrs. "Similar, though less precise results were obtained for the other cancer sites," Tashkin reported. "We found absolutely no suggestion of a dose response."
The data on tobacco use, as expected, revealed "a very potent effect and a clear dose-response relationship -a 21-fold greater risk of developing lung cancer if you smoke more than two packs a day." Similarly high odds obtained for oral/pharyngeal cancer, laryngeal cancer and esophageal cancer. "So, in summary" Tashkin concluded, "we failed to observe a positive association of marijuana use and other potential confounders."
There was time for only one question, said the moderator, and San Francisco oncologist Donald Abrams, M.D., was already at the microphone: "You don't see any positive correlation, but in at least one category, it almost looked like there was a negative correlation, i.e., a protective effect. Could you comment on that?" [Abrams was referring to Tashkin's lung-cancer data for marijuana-only smokers, 1-10 j-yrs.]
"Yes," said Tashkin. "The odds ratios are less than one almost consistently, and in one category that relationship was significant, but I think that it would be difficult to extract from these data the conclusion that marijuana is protective against lung cancer. But that is not an unreasonable hypothesis."
Only if those people are already argumentative, self absorbed and grumpy.
Just a note ... it is the sugars in the processed tobbaco that does the harm.
natural cured products do much less damage.... if any any
Are you sure they're smoking pot and not drinking? Pot smokers are normally very laid back (or that's what I hear).
uhhhh.........yeah..........okay..........uhhhhh..........what were we talking about?............
I guess that means cigarette smoking doesn't cause lung cancer either, since it contains the same pollutants as pot except it has nicotine.
Dope smoking still makes you dopey and act goofy, plus makes you a fat lazy useless unemployable member of society.
Well, what are we waiting for?
Tobacco companies should extact the nicotene from tobacco.
Then extract the THC from pot.
Then put the nicotene in pot.
And finally--a safe cigarette, and I can take up smoking again!!!!
Well then.
I suppose there is something in the lungs of smokers that purifies tobbaco smoke,--
Such that their exhaled smoke is rendered harmless.
Acapulco gold is..... One bad @ss weed!
I remember that one too!
Yea, and tell that to Bob Marley's family.
For example, it took Wolfie almost 2 months after this was published to get this posted :P
Cancer from his head to his toes, IIRC.
Sugars in processed tobacco? never heard of that one.
Tobbacco is picked, the cured in temperature/humidity controlled barns. The better control during the curing process the better the tobacco. Then it is bid on by tobacco buyers. You CAN buy tobacco leaves and grind it up yourself if you like, It doesn't taste or smoke any different than store bought tobacco, unless you get a green leaf. I used to grow and cure my own stuff, but it's a time consuming hobby.
The only additives you might find in comercial tobacco is traces of herbicides and insecticides, which may or may not have cancer causing effects.
Sugar? No way. different varities of tobacco plants is what
gives you different tobacco tastes.
I wonder what the incidence of lung cancer was in our ancestors who each night sat around the campfire for warmth and breathed smoke when the wind swirled? Oh, I forgot; they died of starvation, bear bites, bacterial/viral disease, etc. Never made it to old age.
"Onward through the fog"...Oat Willie
Grow hemp then extract the nicotine from those nicotine patches and spray it on.
But, since you've quit it's better not to take up the habit again. I've been smoke free for 7 months now, and still get the cravings once in a while, but I feel alot better, and don't have that stale smoke smell on my clothes anymore. Strange how you don't notice that when you are a smoker.
Pot causes malignant melanoma?
ping
Do you think Bob Marley just smoked pot? I'll bet he found all sorts of ways to abuse himself...which, if that is typical of the longterm heavy user, is why I'm skeptical about the findings of this study.
marijuana doesn't have tar tho.
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