A new study from UCLA finds no link between marijuana smoking and lung cancer. Some details from a Reuters report:
The study, which compared the lifestyles of 611 Los Angeles County lung cancer patients and 601 patients with head and neck cancers with those of 1,040 people without cancer, found no elevated cancer risk for even the heaviest pot smokers. It did find a 20-fold increased risk of lung cancer in people who smoked two or more packs of cigarettes a day……
Previous studies showed marijuana tar contained about 50 percent more of the chemicals linked to lung cancer, compared with tobacco tar….In addition, smoking a marijuana joint deposits four times more tar in the lungs than smoking an equivalent amount of tobacco.
[Dr. Donald Tashkin] theorized that tetrahydrocannabinol, or THC, a chemical in marijuana smoke that produces its psychotropic effect, may encourage aging, damaged cells to die off before they become cancerous.
In an earlier discussion of his research on pot and cancer, Dr. Tashkin even offered that, given his data, it is not an unreasonable hypothesis to further explore that marijuana just might have some protective effect against lung cancer.