Breathe easy, tokers.
Conclusion/findings from “Marijuana Use and the Risk of Upper Aerodigestive Tract Cancers: Results of a Population-Based Case-Control” by Prof. Donald Tashkin, University of California at Los Angeles
You’d think it would have been very big news in June 2005 when UCLA medical school professor Donald Tashkin reported that components of marijuana smoke — although they damage cells in respiratory tissue — somehow prevent them from becoming malignant.
In other words, something in marijuana exerts an anti-cancer effect!
The National Institute on Drug Abuse (NIDA), which supported Tashkin’s marijuana-related research over the decades, readily gave him a grant in 2002 to conduct a large, population-based, case-controlled study that would prove definitively that heavy, long-term marijuana use increases the risk of lung and upper-airways cancers.
What Tashkin and his colleagues unexpectedly found, however, disproved their hypothesis.
Tashkin’s team interviewed 1,212 cancer patients from the Los Angeles County Cancer Surveillance program, matched for age, gender, and neighborhood with 1,040 cancer-free controls. Marijuana use was measured in “joint years” (number of years smoked times number of joints per day).
It turned out that increased marijuana use did not result in higher rates of lung and pharyngeal cancer, whereas tobacco smokers were at greater risk the more they smoked. Tobacco smokers who also smoked marijuana were at slightly lower risk of getting lung cancer than tobacco-only smokers.