Question: Does Smoking Marijuana Cause Lung Cancer?
The link between smoking tobacco and lung cancer is undeniable, but does smoking marijuana cause lung cancer, too? The short answer -- maybe.
In 2006, many of us in medicine were shocked when a review of research to date did not show an increase in lung cancer related to marijuana use. There was even a suggestion that marijuana had a protective effect against lung cancer. More recent studies, in contrast, do appear to link smoking marijuana with lung cancer, although the results are mixed
One study demonstrated a doubling in lung cancer for male marijuana smokers who also used tobacco (i.e. for men who smoked the same amount, the risk of lung cancer was twice as high for men who also used marijuana.) Another study found that long-term use of marijuana increased the risk of lung cancer in young adults (55 and under), with the risk increasing in proportion to the amount of marijuana smoked.
Efffects of Marijuana on the Lungs
Researchers have found that regular use of marijuana causes injury to the airway that can be seen visibly as well as under the microscope. That said, regular smoking of marijuana does not seem to cause any significant changes in lung function, nor does it appear to increase the risk of COPD.
Why the Controversy about Cancer Risk?
Since marijuana is illegal, it is hard to do the controlled studies that have been done with tobacco. Because of this, it helps to look at what we do know about marijuana:
- Many of the carcinogens and co-carcinogens present in tobacco smoke are also present in smoke from marijuana.
- Marijuana smoking does cause inflammation and cell damage, and it has been associated with pre-cancerous changes in lung tissue.
- Marijuana has been shown to cause immune system dysfunction, possibly predisposing individuals to cancer.
Bottom line: Though marijuana most likely pales in cancer risk when compared to cigarette smoking, it's better to play it safe. There are reasons in addition to lung cancer risk (and the fact that it is illegal in most states) to avoid marijuana. Marijuana likely increases the risk of testicular cancer, prostate cancer, cervical cancer, a type of brain tumor, and the risk of leukemia in the offspring of women who use it during pregnancy.
- The Health Effects of Mariquana
- Mariquana Use Linked to Testicular Cancer
- Basic Facts About Mariquana
This article talks about the recreational use of marijuana, but what about medical marijuana?
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