The health consequences of cannabis use in developing countries are largely unknown beacuse of limited and non-systematic research, but there is no reason a priori to expect that biological effects on individuals in these populations would be substantially different to what has been observed in developed countries. However, other consequences might be different given the cultural and social differences between countries.
Hemp crops are tall, have thick foliage, and can be planted densely, and thus can be grown as a smother crop to kill tough weeds.[45] Using hemp this way can help farmers avoid the use of herbicides, gain organic certification, and gain the benefits of crop rotation. However, due to the plant's rapid and dense growth characteristics, some jurisdictions consider hemp a prohibited and noxious weed, much like Scotch Broom.[citation needed]
One of the reasons hemp fiber has been valued is because of its length. The primary bast fibers in the bark are 5–40 mm long, and are amalgamated in fiber bundles which can be 1–5 m long (secondary bast fibers are about 2 mm long). The woody core fibers are short—about 0.55 mm—and like hardwood fibers are cemented together with considerable lignin. The core fibers are generally considered too short for high grade paper applications (a length of 3 mm is considered ideal), and too much lignin is present. While the long bast fibers have been used to make paper almost for 2 millennia, the woody core fibers have rarely been so used. Nevertheless it has been suggested that the core fibers could be used for paper making, providing appropriate technology was developed (de Groot et al. 1998). In any event, the core fibers, have found a variety of uses, as detailed below. The long, lignin-poor bast fibers also have considerable potential to be used in many non-paper, non-textile applications, as noted below.
The main psychoactive constituent of Cannabis was identified as delta-9-tetrahydrocannabinol (THC). In 1986, an isomer of synthetic delta-9-THC in sesame oil was licensed and approved for the treatment of chemotherapy -associated nausea and vomiting under the generic name dronabinol. Clinical trials determined that dronabinol was as effective as or better than other antiemetic agents available at the time.[8] Dronabinol was also studied for its ability to stimulate weight gain in patients with AIDS in the late 1980s. Thus, the indications were expanded to include treatment of anorexia associated with human immunodeficiency virus infection in 1992. Clinical trial results showed no statistically significant weight gain, although patients reported an improvement in appetite.[9,10] Another important cannabinoid found in Cannabis is CBD.[11] This is a nonpsychoactive cannabinoid, which is an analog of THC.

Quality is a particular concern, because cannabis plants easily soak up heavy metals from pesticides and other contaminants, Marcu says. If you are buying online, look for a company that documents how it tests its products. (If the website doesn’t indicate this, call and ask.) “Buying from a reputable manufacturer is crucial, because it matters how the plant is cultivated and processed,” Dr. Maroon says. One clue that a company is cutting corners: too low a cost. Good CBD is pricey—a bottle of high-quality capsules is sold in Cohen’s office for $140. But for many, it’s worth the money. Roth spent $60 on her tiny bottle. But when her energy returned the day she started taking CBD, she decided that was a small price to pay.


In the 1970s, the taxonomic classification of Cannabis took on added significance in North America. Laws prohibiting Cannabis in the United States and Canada specifically named products of C. sativa as prohibited materials. Enterprising attorneys for the defense in a few drug busts argued that the seized Cannabis material may not have been C. sativa, and was therefore not prohibited by law. Attorneys on both sides recruited botanists to provide expert testimony. Among those testifying for the prosecution was Dr. Ernest Small, while Dr. Richard E. Schultes and others testified for the defense. The botanists engaged in heated debate (outside of court), and both camps impugned the other's integrity.[56][57] The defense attorneys were not often successful in winning their case, because the intent of the law was clear.[64]

A 2012 review found that the THC content in marijuana had increased worldwide from 1970 to 2009.[150] It is unclear, however, whether the increase in THC content has caused people to consume more THC or if users adjust based on the potency of the cannabis. It is likely that the higher THC content allows people to ingest less tar. At the same time, CBD levels in seized samples have lowered, in part because of the desire to produce higher THC levels and because more illegal growers cultivate indoors using artificial lights. This helps avoid detection but reduces the CBD production of the plant.[151]


Cannabis has long had an image problem, because of the extremely widespread use of “narcotic” cultivars as illegal intoxicants. The US Drug Enforcement Administration has the mandate of eliminating illicit and wild marijuana, which it does very well (Fig. 54–56). Those interested in establishing and developing legitimate industries based on fiber and oilseed applications have had to struggle against considerable opposition from many in the political and law enforcement arenas. The United States National Institute on Drug Abuse (NIDA) information web site on marijuana, which reflects a negative view of cannabis, is at www.nida.nih.gov/DrugPages/Marijuana.html, and reflects several basic fears: (1) growing Cannabis plants makes law enforcement more difficult, because of the need to ensure that all plants cultivated are legitimate; (2) utilization of legitimate Cannabis products makes it much more difficult to maintain the image of the illegitimate products as dangerous; (3) many in the movements backing development of hemp are doing so as a subterfuge to promote legalization of recreational use of marijuana; and (4) THC (and perhaps other constituents) in Cannabis are so harmful that their presence in any amount in any material (food, medicine or even fiber product) represents a health hazard that is best dealt with by a total proscription.

Finding cultivars suited to local conditions is a key to success. Hemp prefers warm growing conditions, and the best European fiber strains are photoperiodically adapted to flowering in southern Europe, which provides seasons of at least 4 months for fiber, and 5.5 months for seed production. Asian land races are similarly adapted to long seasons. In Canada, many of the available cultivars flower too late in the season for fiber production, and the same may be predicted for the northern US. Fiber production should also be governed by availability of moisture throughout the season, and the need for high humidity in the late summer and fall for retting, so that large areas of the interior and west of North America are not adapted to growing fiber hemp. The US Corn Belt has traditionally been considered to be best for fiber hemp. There are very few cultivars dedicated to oilseed production (such as ‘Finola’ and ‘Anka’) or that at least are known to produce good oilseed crops (such as ‘Fasamo’ and ‘Uniko-B’). Oilseed production was a specialty of the USSR, and there is some likelihood that northern regions of North America may find short-season, short-stature oilseed cultivars ideal.
From 1982 to 2002 the EU provided the equivalent of about 50 million dollars to develop new flax and hemp harvesting and fiber processing technologies (Karus et al. 2000). Because of the similarities of flax and hemp, the technologies developed for one usually are adaptable to the other. In addition, various European nations and private firms contributed to the development of hemp technologies. Accordingly, Europe is far more advanced in hemp development with respect to all fiber-based applications than other parts of the world. The EU currently dedicates about 30,000 ha to hemp production. France is the leading country in hemp cultivation in the EU, and 95% of the non-seed production is used for “specialty pulp” as described below. Harvesting and processing machinery for fiber hemp is highly advanced in Europe, and some has been imported into Canada. However, there is insufficient fiber processing capacity to handle hemp produced in Canada.
It’s a truism to state that pain is an inevitable part of life. And it’s true that we all, from time to time, experience pain that is short-lived and treatable. But those who deal with chronic pain know the debilitating, life-sucking reality of this condition. And traditional medications often come with long lists of side effects which can be as debilitating as the pain itself.

CBD may also enhance uptake of cytotoxic drugs into malignant cells. Activation of the transient receptor potential vanilloid type 2 (TRPV2) has been shown to inhibit proliferation of human glioblastoma multiforme cells and overcome resistance to the chemotherapy agent carmustine. [31] One study showed that coadministration of THC and CBD over single-agent usage had greater antiproliferative activity in an in vitro study with multiple human glioblastoma multiforme cell lines.[32] In an in vitro model, CBD increased TRPV2 activation and increased uptake of cytotoxic drugs, leading to apoptosis of glioma cells without affecting normal human astrocytes. This suggests that coadministration of CBD with cytotoxic agents may increase drug uptake and potentiate cell death in human glioma cells. Also, CBD together with THC may enhance the antitumor activity of classic chemotherapeutic drugs such as temozolomide in some mouse models of cancer.[13,33] A meta-analysis of 34 in vitro and in vivo studies of cannabinoids in glioma reported that all but one study confirmed that cannabinoids selectively kill tumor cells.[34]


Medical cannabis (or medical marijuana) refers to the use of cannabis and its constituent cannabinoids, to treat disease or improve symptoms. Cannabis is used to reduce nausea and vomiting during chemotherapy, to improve appetite in people with HIV/AIDS, and to treat chronic pain and muscle spasms.[102][103] Cannabinoids are under preliminary research for their potential to affect stroke.[104]
According to the United Nations Office on Drugs and Crime (UNODC), "the amount of THC present in a cannabis sample is generally used as a measure of cannabis potency."[149] The three main forms of cannabis products are the flower, resin (hashish), and oil (hash oil). The UNODC states that cannabis often contains 5% THC content, resin "can contain up to 20% THC content", and that "Cannabis oil may contain more than 60% THC content."[149]
Reference citations in some PDQ cancer information summaries may include links to external websites that are operated by individuals or organizations for the purpose of marketing or advocating the use of specific treatments or products. These reference citations are included for informational purposes only. Their inclusion should not be viewed as an endorsement of the content of the websites, or of any treatment or product, by the PDQ Integrative, Alternative, and Complementary Therapies Editorial Board or the National Cancer Institute.
The gateway effect may appear due to social factors involved in using any illegal drug. Because of the illegal status of cannabis, its consumers are likely to find themselves in situations allowing them to acquaint with individuals using or selling other illegal drugs.[256][257] Utilizing this argument some studies have shown that alcohol and tobacco may additionally be regarded as gateway drugs;[258] however, a more parsimonious explanation could be that cannabis is simply more readily available (and at an earlier age) than illegal hard drugs. In turn alcohol and tobacco are easier to obtain at an earlier point than is cannabis (though the reverse may be true in some areas), thus leading to the "gateway sequence" in those individuals since they are most likely to experiment with any drug offered.[249]
Under federal law, cannabis (from which both CBD and marijuana are derived) is illegal everywhere, although the laws against it aren’t generally enforced in states that have legalized marijuana. Some manufacturers claim that CBD culled from legally imported industrial hemp, which has little to no THC, is fine to ship across the U.S., but many experts disagree, noting that because hemp comes from the same species as marijuana, cannabis sativa, all CBD falls under the DEA’s Schedule 1 designation. “This creative interpretation of the law runs afoul of reality,” says the Brookings Institution, a Washington, DC, think tank.

In an in vivo model using severe combined immunodeficient mice, subcutaneous tumors were generated by inoculating the animals with cells from human non-small cell lung carcinoma cell lines.[23] Tumor growth was inhibited by 60% in THC-treated mice compared with vehicle-treated control mice. Tumor specimens revealed that THC had antiangiogenic and antiproliferative effects. However, research with immunocompetent murine tumor models has demonstrated immunosuppression and enhanced tumor growth in mice treated with THC.[24,25]

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. Many countries regulate limits for psychoactive compound (THC) concentrations in products labeled as hemp.
CBD’s potential usefulness in treating certain conditions is yet another argument in favor of legalizing the entire cannabis plant. Removing cannabis from the federal list of Schedule I narcotics that are illegal under the Controlled Substances Act would allow scientists to research its full medical potential and pharmaceutical companies in the United States to develop marijuana-based drugs and submit them for FDA approval. Government-regulated labs could test products like CBD oil to ensure safety and quality. Doctors could prescribe marijuana- based medicines with full knowledge of potential side effects and drug interactions, and without fear of losing their medical licenses or being thrown in jail.
The vegetable oils have been classified by “iodine value” as drying (120–200), semi-drying (100–120), and non-drying (80–100), which is determined by the degree of saturation of the fatty acids present (Raie et al. 1995). Good coating materials prepared from vegetable oil depend on the nature and number of double bonds present in the fatty acids. Linseed oil, a drying oil, has a very high percentage of linolenic acid. Hempseed oil has been classified as a semi-drying oil, like soybean oil, and is therefore more suited to edible than industrial oil purposes. Nevertheless hemp oil has found applications in the past in paints, varnishes, sealants, lubricants for machinery, and printing inks. However, such industrial end uses are not presently feasible as the oil is considered too expensive (de Guzman 2001). Larger production volumes and lower prices may be possible, in which case hemp oil may find industrial uses similar to those of linseed (flax), soybean, and sunflower oils, which are presently used in paints, inks, solvents, binders, and in polymer plastics. Hemp shows a remarkable range of variation in oil constituents, and selection for oilseed cultivars with high content of valued industrial constituents is in progress.
Cannabis can be prepared into various foods generally called ‘edibles’. It takes between 1-3 hours to feel the effects after eating cannabis.2 Impatient or naïve users may believe they have not taken enough to feel the effects, and if they consume more they may find later that the psychoactive effects are unpleasantly strong. When edible products have inconsistent levels of THC even experienced users may find it difficult to regulate the amount consumed.
Fig. 6. ‘Finola,’ the first cultivar of Cannabis sativa bred exclusively for grain. (Courtesy of the breeder, J.C. Callaway, Univ. Kuopio, Finland.) Fig. 7. ‘Anka,’ the first registered North American bred cultivar of Cannabis sativa. This variety is best suited for grain production. (Courtesy of the breeder, P. Dragla, and of the Industrial Hemp Seed Development Company, Chatham, Ontario.)
Understanding the mechanism of cannabinoid-induced analgesia has been increased through the study of cannabinoid receptors, endocannabinoids, and synthetic agonists and antagonists. Cannabinoids produce analgesia through supraspinal, spinal, and peripheral modes of action, acting on both ascending and descending pain pathways.[41] The CB1 receptor is found in both the central nervous system (CNS) and in peripheral nerve terminals. Similar to opioid receptors, increased levels of the CB1 receptor are found in regions of the brain that regulate nociceptive processing.[42] CB2 receptors, located predominantly in peripheral tissue, exist at very low levels in the CNS. With the development of receptor-specific antagonists, additional information about the roles of the receptors and endogenous cannabinoids in the modulation of pain has been obtained.[43,44]
In addition to providing useful fibers, hemp seed also has high nutritional value. and the plant can be used to make biodegradable plastics, some fuels, and a variety of other things. Hemp foods including but not limited to hemp energy bars, hemp salad dressing,hemp milk, hemp protein shakes, hemp oil gel caps and hemp protein powder are among some of the health products being produced today. Visit the Hemp Education pages to learn more!

The plant is also known as hemp, although this term is often used to refer only to varieties of Cannabis cultivated for non-drug use. Cannabis has long been used for hemp fibre, for hemp oils, for medicinal purposes, and as a recreational drug. Industrial hemp products are made from cannabis plants selected to produce an abundance of fiber. To satisfy the UN Narcotics Convention, some cannabis strains have been bred to produce minimal levels of tetrahydrocannabinol (THC), the principal psychoactive constituent. Some strains have been selectively bred to produce a maximum of THC (a cannabinoid), the strength of which is enhanced by curing the flowers. Various compounds, including hashish and hash oil, are extracted from the plant.[7]
One of the most curious uses of hemp is as a fence to prevent pollen transfer in commercial production of seeds. Isolation distances for ensuring that seeds produced are pure are considerable for many plants, and often impractical. At one point in the 1980s, the only permitted use of hemp in Germany was as a fence or hedge to prevent plots of beets being used for seed production from being contaminated by pollen from ruderal beets. The high and rather inpenetrable hedge that hemp can produce was considered unsurpassed by any other species for the purpose. As well, the sticky leaves of hemp were thought to trap pollen. However, Saeglitz et al. (2000) demonstrated that the spread of beet pollen is not effectively prevented by hemp hedges. Fiber (i.e. tall) cultivars of hemp were also once used in Europe as wind-breaks, protecting vulnerable crops against wind damage. Although hemp plants can lodge, on the whole very tall hemp is remarkably resistant against wind.

Hemp is used to make a variety of commercial and industrial products including rope, textiles, clothing, shoes, food, paper, bioplastics, insulation, and biofuel.[5] The bast fibers can be used to make textiles that are 100% hemp, but they are commonly blended with other fibers, such as flax, cotton or silk, as well as virgin and recycled polyester, to make woven fabrics for apparel and furnishings. The inner two fibers of the plant are more woody and typically have industrial applications, such as mulch, animal bedding and litter. When oxidized (often erroneously referred to as "drying"), hemp oil from the seeds becomes solid and can be used in the manufacture of oil-based paints, in creams as a moisturizing agent, for cooking, and in plastics. Hemp seeds have been used in bird feed mix as well.[13] A survey in 2003 showed that more than 95% of hemp seed sold in the European Union was used in animal and bird feed.[14]
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