Kevin Brown, a medical marijuana user, at the Apothecarium, a medical cannabis
dispensary in San Francisco.
Photo Credit: AP Images; December 2011
An article (“Marijuana: The High and the Low”; Feb 2014), by Jerome Groopman, in The New York Review of Books gives a balanced and nuanced view on the benefits and concerns raised about the use of marijuana, not only for medical use but also as a recreational drug.
In the summer of 2006, a young scientist from Israel joined my laboratory. He came to learn how viruses attack cells, a major focus of my research program. And I looked forward to drawing on his expertise in an emerging area of science that intrigued me: the biological effects of cannabinoids, the active chemical compounds in the marijuana plant. The Israeli researcher had trained at Jerusalem’s Hebrew University with Professor Raphael Mechoulam, a chemist credited with the discovery in 1964 of delta-9-tetrahydrocannabinol (THC), the primary psychoactive compound in marijuana. Mechoulam later characterized cannabidiol (CBD), a related substance plentiful in the plant, as distinct from THC in that it had no discernible effects on mood, perception, wakefulness, or appetite.1
The work of the young scientist proved productive. In short order, he tested the effects of several cannabinoids on a herpes virus that promotes the development of Kaposi’s sarcoma, a disfiguring and sometimes fatal tumor among people with impaired immunity, like those with AIDS. It turned out that CBD, the plentiful, nonpsychoactive compound, could switch off the malignant effects of the virus.2 Scientists in my department also found that cannabinoids could alter how white blood cells migrated in response to physiological stimuli, a key aspect of immune defense; other research teams found that THC inhibited the growth and spread of lung cancer and CBD of breast cancer in laboratory models.3 Clearly, chemicals in the plant could have diverse and potent effects on normal and malignant cells.
But what I found most fascinating was that we have a natural or “endogenous” cannabinoid system. In 1988, researchers identified a specific docking site, or receptor, on the surface of cells in the brain that bound THC. This first receptor was termed cannabinoid receptor 1, or CB1.4 Five years later, a second receptor for cannabinoids, CB2, was found.5 This latter docking protein was less plentiful in the central nervous system but richly present on white blood cells. Again, it was Raphael Mechoulam who discovered the first endogenous cannabinoid, a fatty acid in the brain, which he termed “anandamide.” (The name is derived from the Sanskrit word ananda, which means “bliss.”) When anandamide attached to CB1 it triggered a cascade of biochemical changes within our neurons.6What this article suggests, and I encourage you to read it in its entirety, is that marijuana has many positive and beneficial uses for humans, including acting as an effective pain reliever; there are also some concerns that it might contribute to schizophrenia or other psychoses if marijuana is initiated at too young an age. The problem is that government restrictions and controls have made it difficult to near-impossible study how marijuana affects humans; the discussion around marijuana use has become politicized and polarized with persons lining up on each side championing their views.
The article ends on a cautionary, and I would suggest, rational and thoughtful, note:
Perhaps as states legalize marijuana, this barrier to research will be lowered, as it was for stem cell research, once restricted by federal law. And as more studies are conducted on marijuana for medical or recreational uses, opponents and enthusiasts may both discover that they were neither entirely right nor entirely wrong.
Read the article at [NYRB]