Study: Smoking Pot Does NOT Cause Lung Cancer!

Libby beat me to this one, too. I’d really like to see this in some other media sources, but this is very exciting news. In fact, it should be front page.
From Fred Gardner at CounterPunch, comes this:

Marijuana smoking -“even heavy longterm use”- does not cause cancer of the lung, upper airwaves, 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, prospectively designed, 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-airwaves cancers.”

So here was a study going in with the notion that they would find a causal relationship between marijuana smoking and lung cancer. What did they find?
Absolutely no increase in odds of marijuana smokers getting cancer, regardless of amount of use.
In fact, in all categories of pot smokers, the odds of getting lung cancer were actually less than in the control group!