Cannabis (/ˈkænəbɪs/) is a genus of flowering plants that includes a single species, Cannabis sativa, which is sometimes divided into two additional species, Cannabis indica, and Cannabis ruderalis. Cannabis is indigenous to Central Asia and South Asia. Cannabis has long been used for fibre (hemp), for seed and seed oils, for medicinal purposes, and as a recreational drug.
Cannabis plants produce a unique family of terpeno-phenolic compounds called cannabinoids, which produce the “high” one experiences from consuming marijuana. There are 483 identifiable chemical constituents known to exist in the cannabis plant, and at least 85 different cannabinoids have been isolated from the plant. The most psychoactive cannabinoid found in the cannabis plant is tetrahydrocannabinol (or delta-9-tetrahydrocannabinol, commonly known as THC). Other cannabinoids include delta-8-tetrahydrocannabinol, cannabidiol (CBD), cannabinol (CBN),cannabicyclol (CBL), cannabichromene (CBC) and cannabigerol (CBG); they have less psychotropic effects than THC, but may play a role in the overall effect of cannabis. The most studied are THC, CBD and CBN.
Since the early 1970s, Cannabis plants have been categorized by their chemical phenotype or “chemotype,” based on the overall amount of THC produced, and on the ratio of THC to CBD. Although overall cannabinoid production is influenced by environmental factors, the THC/CBD ratio is genetically determined and remains fixed throughout the life of a plant.
The Cannabis plant has a history of medicinal use dating back thousands of years across many cultures. Medical cannabis has several potential beneficial effects. Modern research suggests that cannabis is a valuable aid in the treatment of a wide range of clinical applications. These include pain relief — particularly of neuropathic pain (pain from nerve damage) — nausea, spasticity, glaucoma, and movement disorders. Cannabis is also a powerful appetite stimulant, specifically for patients suffering from HIV, the AIDS wasting syndrome, or dementia. Emerging research suggests that cannabis’ medicinal properties may protect the body against some types of malignant tumors and are neuroprotective.
Currently, more than 60 U.S. and international health organizations – including the American Public Health Association, Health Canada and the Federation of American Scientists – support granting patients immediate legal access to medicinal cannabis under a physician’s supervision. Several others, including the American Cancer Society and the American Medical Association support the facilitation of wide-scale, clinical research trials so that physicians may better assess cannabis’ medical potential. In addition, a 1991 Harvard study found that 44 percent of oncologists had previously advised marijuana therapy to their patients. Fifty percent responded they would do so if marijuana was legal. A more recent national survey performed by researchers at Providence Rhode Island Hospital found that nearly half of physicians with opinions supported legalizing medical marijuana.
Synthetic cannabinoids are available as prescription drugs in some countries; examples include: dronabinol (available in the United States and Canada) and nabilone (available in Canada, Mexico, the United Kingdom, and the United States).
Currently 21 U.S. states (including California) and the District of Columbia have approved the use of cannabis for medical purposes.
After conducting a nearly two-year review of the medical literature, investigators at the National Academy of Sciences, Institute of Medicine affirmed:
“Scientific data indicate the potential therapeutic value of cannabinoid drugs … for pain relief, control of nausea and vomiting, and appetite stimulation. … Except for the harms associated with smoking, the adverse effects of marijuana use are within the range tolerated for other medications.”
Cannabis is a popular recreational drug around the world, only behind alcohol, caffeine and tobacco. In the United States alone, it is believed that over 100 million Americans have tried Cannabis, with 25 million Americans having used it within the past year.
The psychoactive effects of Cannabis are known to have a biphasic nature. Primary psychoactive effects include a state of relaxation, and to a lesser degree, euphoria from its main psychoactive compound, tetrahydrocannabinol. Secondary psychoactive effects, such as a facility for philosophical thinking, introspection and metacognition have been reported amongst cases of anxiety and paranoia. Finally, the tertiary psychoactive effects of the drug cannabis, can include an increase in heart rate and hunger, believed to be caused by 11-OH-THC, a psychoactive metabolite of THC produced in the liver.
The plant Cannabis sativa is known to cause more of a “high” by stimulating hunger and by producing a rather more comedic, or energetic feeling. Conversely, the Cannabis indica plant is known to cause more of a “stoned” or meditative feeling, possibly because of a higher CBD to THC ratio.
Cannabidiol (CBD), which has no psychotropic effects by itself (although sometimes showing a small stimulant effect, similar to caffeine), attenuates, or reduces the higher anxiety levels caused by THC alone.
According to Delphic analysis by British researchers in 2007, Cannabis has a lower risk factor for dependence compared to both nicotine and alcohol. However, everyday use of Cannabis can in some cases be correlated with psychological withdrawal symptoms such as irritability and insomnia, and evidence could suggest that if a user experiences stress, the likeliness of getting a panic attack increases because of an increase of THC metabolites. However, Cannabis withdrawal symptoms are typically mild and are not life-threatening.
The term Hemp is used to name the durable soft fiber from the Cannabis Plant stem (stalk).Cannabis sativa cultivars are used for fibers due to their long stems; Sativa varieties may grow more than six metres tall. However, hemp can refer to any industrial or foodstuff product that is not intended for use as a drug.
Hemp is valuable in tens of thousands of commercial products, especially as fibre ranging from paper, cordage, construction material and textiles in general, to clothing. Hemp is stronger and longer-lasting than cotton. It also is a useful source of foodstuffs (hemp milk, hemp seed, hemp oil) and biofuels. Hemp has been used by many civilizations, from China to Europe (and later North America) during the last 12,000 years.
Approximately 44% of the weight of hempseed is edible oils, containing about 80% essential fatty acids (EFAs); e.g., linoleic acid, omega-6 (LA, 55%), alpha-linolenic acid, omega-3 (ALA, 22%), in addition to gamma-linolenic acid, omega-6 (GLA, 1–4%) and stearidonic acid, omega-3 (SDA, 0–2%). Proteins (including edestin) are the other major component (33%). Hempseed’s amino acid profile is “complete” when compared to more common sources of proteins such as meat, milk, eggs and soy.Hemp protein contains all nutritionally significant amino acids, including the 9 essential ones adult bodies cannot produce. Proteins are considered complete when they contain all the essential amino acids in sufficient quantities and ratios to meet the body’s needs. The proportions of linoleic acid and alpha-linolenic acid in one tablespoon (15 ml) per day of hemp oil easily provides human daily requirements for EFAs.
This article is intended for informational purposes only and is not a substitute for medical advice. For additional information, please see the Wikipedia entry for Cannabis. The text above is adapted under Wikipedia’s Creative Commons Attribution-ShareAlike License.