More Evidence on Marijuana and Cancer

The evidence continues to mount that cannabinoids -- the unique, active components in marijuana -- fight cancer. The latest such study , just published in the Journal of Clinical Investigation, shows that THC can kill glioma cells through a process known as autophagy. Gioma is a particularly deadly form of brain cancer that afflicts, among others, Sen. Edward M. Kennedy (D-Mass.).

The good news is that this study got a decent amount of media attention. The bad news is that much of the coverage lacked context or presented information in a confusing or misleading way. Case in point: the April 1 story from the Reuters wire service.

Reuters reporter Michael Kahn presents the finding as if it were something brand new, failing to note the extensive evidence accumulated since the 1970s that cannabinoids fight various types of tumors. It reports that "studies have suggested" that marijuana may cause cancer, omitting the fact that the largest, most well-controlled studies have found precisely the opposite.

And finally, in a warning of possible risks of cannabinoid drugs, the article hopelessly jumbles cannabinoids -- drugs like THC and its plant and synthetic cousins -- with drugs designed to block the CB1 receptor through which these substances operate, mistakenly referring to these CB1-blocking drugs as cannabinoids. In fact, they're more like anti-cannabinoids, and if anything the harmful effects of these CB1 blockers (increased rates of depression and anxiety, for example) reaffirm that cannabinoids often have good and helpful effects.