The cannabis plant is native to almost all climate zones–from Siberia to southern Africa–and is now thought to exist in three varieties: cannabis sativa, cannabis indica and cannabis ruderalis. Each variety has distinct characteristics. Cannabis sativa can grow to be very tall and tree-like, while Cannabis indica is usually short and bushy. Ruderalis is generally spindly and short, and has largely been ignored in both practical use and as the object of scientific study, though with the increased interest in both medical and industrial uses of cannabis, this is changing.
Humans have used cannabis for thousands of years for a variety of purposes. Hemp fibers are thought to have been fashioned into rope, twine and cloth at least as long as 10,000 years ago and perhaps much longer, and were probably the source of the first paper made in China more than 2,000 years ago. Human interaction with cannabis is probably much older, however. Some scientists have even speculated that cannabis and humans as well as other animals have co-evolved, because all vertebrates, including mammals, birds, fish and reptiles, have receptors for and produce substances known as endocannabinoids that are similar to compounds found in the cannabis plant–hence their name. Discovered only in the late 1980s, the endocannabinoid system is one of a number of systems that help maintain balance, or homeostasis, in most body functions and systems. Because the endocannabinoid system is so vitally important, it has been the subject of thousands of research studies conducted around the world in recent years.
The endocannabinoid system’s role in human physiology is broad and multi-faceted. The central nervous system, the immune system, cardiovascular system, reproductive system, gastrointestinal and urinary tracts all contain cannabinoid receptors and are regulated by cannabinoids–with one important exception: the brainstem where, among other vital functions, respiration is controlled. This is why cannabis, unlike opiates, does not suppress breathing, even at high doses. Endocannabinoid production declines as people age, a process that may play an important role in the development of age-related and degenerative diseases such as atherosclerosis and cardiovascular disease, arthritis, osteoporosis and possibly a number of cancers as well as Alzheimer’s disease and Parkinson’s disease.
And so it would seem to be a natural conclusion that replacing declining endocannabinoid levels with outside sources of cannabinoids would be desirable. As it happens, the only source of cannabinoids outside the human body is the cannabis plant. It is little wonder then that cannabis has been used as a medicine for thousands of years or that, after decades of neglect and vilification, it is again assuming an important role in treating and possibly preventing a great many medical conditions. Stay tuned. The most exciting part of the story is yet to come.
Alan Shackelford, M.D., graduated from the University of Heidelberg School of Medicine and trained at major teaching hospitals of Harvard Medical School in internal medicine, nutritional medicine and hyperalimentation, and behavioral medicine. He is principle physician for Intermedical Consulting, LLC and Amarimed of Colorado, LLC and can be contacted at Amarimed.com.