Study show risk of cancer lower for cannabis users than non-users

NORML News, Winter 2004

Even heavy longterm smoking of cannabis is not associated cancer of the lung, upper airwaves, or esophagus, according to a case-control study by Dr. Donald Tashken presented to the annual conference of the International Cannabinoid Research Society.

Coming from Tashkin, this conclusion had extra significance. Over the years, Tashkinâ??s lab at UCLA has produced evidence of the damage that marijuana smoke wreaks on bronchial tissue. It is Tashkinâ??s research that drug warriors often cite in trying to link marijuana to lung cancer. Tashkin himself has long believed in a causal relationship. â??Our major hypothesis,â?� he told the ICRS, â??was that heavy, longterm use of marijuana will increase the risk of lung and upperairwaves cancers.â?�

The study included 1,209 residents of Los Angeles aged 18-59 with cancer (611 lung, 403 oral/pharyngeal, 90 laryngeal, and 108 esophageal), and 1040 cancer-free controls. Exposure to cannabis was measured in joint years (1 joint year = 365 joints).

Compared with subjects who had used less than one joint year, the risk for lung cancer was 0.78 for 1-10 joint years, 0.74 for 10-30 joint years, 0.85 for 30-60 joint years, and 0.81 for more than 60 joint years.

A risk below 1.0 means that the risk for cannabis users was slightly lower than for non-users.

Similar results were obtained for the other cancer sites. There was no dose-response relationship of cancer risk, which means that there was no increased risks for more intensive users.

After presenting the study, Dr Tashkin said â??I think that it would be difficult to extract from these data the conclusion that marijuana is protective against lung cancer. But that is not an unreasonable hypothesis.â?�

The data on tobacco use, as expected, revealed a very potent effect and a clear doseresponse relationship.

Source: Morgenstern H, et al. Marijuana use and cancers of the lung and upper aerodigestive tract: results of a case-control study. Presentation at the ICRS Conference on Cannabinoids, 24-27 June 2005, www.cannabis-med.org

http://www.norml.org.nz/article579.html

I only copy and pasted the title. I feel stupid when I read it.

Umm, probably, it's from a year and a half ago.

sounds good 2 me