Cannabis May Prevent Lung Cancer.

One of the surprising research results from the last decade has been the finding that smoking cannabis does not increase the risk of developing lung cancer or (COPD) among people who do not smoke tobacco, and may indeed confer a mildly protective effect. Beginning in 2001, multiple research teams began to report results showing that smoking cannabis does not, by itself, increase the risk of lung cancer, and this result is now well-established. Many studies did report a strongly synergistic effect, however, between tobacco use and smoking cannabis such that tobacco smokers who also smoked cannabis dramatically increased their already very high risk of developing lung cancer or chronic obstructive pulmonary disease by as much as 300%.