Cannabis and Crohn's

In ancient medicine, the herb, Cannabis sativa L., was widely used to cure disturbances and inflammation of the bowel. Research published in the journal Pharmacology and by the United States (US) National Institute of Health has found that cannabis is effective in treating Crohn’s Disease, which is a form of inflammatory bowel disease (IBD). IBD's such as Ulcerative Colitis and Crohn’s Disease affect over a million people in the US. Many IBD victims suffer from extreme pain, diarrhoea and poor ability to digest food. Up to half of IBD cases are so severe that they ultimately require surgery to remove the affected bowel segment.

In a 2007 study in Australia, The Economic Costs of Crohn’s Disease and Ulcerative Colitis, commissioned by Crohn’s and Colitis Australia (CCA) it was revealed that the (then) annual cost of Crohn’s Disease and Ulcerative Colitis was AU$2.7 billion. In 2013, CCA commissioned another report, Improving Inflammatory Bowel Disease Care Across Australia, which stated: "IBD is becoming more prevalent, more complex, and more severe ... IBD is a chronic and largely hidden disease affecting approximately 1 in 250 people aged 5 – 49 nationally. Australia has one of the highest rates of prevalence and incidence in the world and each year more and more young people are being diagnosed. Over 74,955 Australians are burdened with a constant and often hidden struggle that affects a sufferer’s personal, social and work life". The report went on to estimate that national total hospital costs for IBD are in the order of AU$100 million per annum. Productivity losses attributable to IBD in 2012 were estimated at over AU$380 million. An additional AU$2.7 billion of financial and economic costs have been associated with the management of IBD, Australia-wide.

The past decade has seen a constant rise in publications dealing with the anti-inflammatory effects of cannabinoids and the potential underlying mechanisms. Preclinical data on the ameliorating effect of synthetic and natural cannabinoids in animal models mimicking features of IBD have been rapidly evolving. The reasonable idea that cannabinoids would also be beneficial in IBD patients was mainly based on results from experiments in cannabinoid receptor knock-out mice and on data using cannabinoid receptor agonists and antagonists.

In 2011, a retrospective, observational study examining disease activity, use of medication, need for surgery and hospitalisation before and after cannabis use in 30 patients (26 males) with Crohn's Disease and a questionnaire performed by a different group of patients with Ulcerative Colitis (100) and Crohn's Disease (191), both revealed symptom relief and improvement after use of cannabis. 21 out of 30 of the study individuals reported significant improvement, with patients requiring steroid treatment reduced from 26 to 4. 

A prospective trial in Israel showed complete remission in five of eleven patients suffering Crohn's Disease who were given cannabis twice daily. Authors of the study said it had been reported for years that cannabis lessened the painful symptoms of the inflammatory bowel disease, but the findings had not been proven in a controlled trial. The study, published in Clinical Gastroenterology and Hepatology in 2013, compared 21 patients who did not respond to conventional treatment. Half were given cannabis cigarettes and the other half were given a placebo; cannabis cigarettes with the tetrahydrocannabinol (THC) removed. The results showed improvement in the group treated with the THC-intact cannabis. Those subjects also reported improved sleep and appetite.

The 8-week treatment with THC-rich cannabis caused a decrease in the Crohn's Disease activity index in 90% of patients without producing significant side effects. The mechanisms involved most likely include peripheral actions on cannabinoid receptors 1 and 2 (CB1 and CB2) and may also include central actions. The authors rightfully concluded that a larger patient group is warranted for future studies.

The discovery of cannabinoid receptors and endogenous molecules activating these receptors led to the description of a coordinated network that is inherent to the mammalian organism, the Endocannabinoid System (ECS). This system consists of the canonical cannabinoid receptors (CB1, CB2), their endogenous ligands, anandamide and 2-arachidonoyl glycerol (2-AG), also called endocannabinoids and their synthesising and degrading enzymes. What capsaicin, the pungent ingredient of chilli, is for vanilloid receptors and morphine for opioid receptors, THC is for cannabinoid receptors; the predominant herbal ligand. Thus, THC mimics the actions of anandamide and 2-AG.

The wall of the gastrointestinal tract houses all components of the ECS. Data from 2011 showed that these components are differentially expressed in human IBD indicating a regulatory role in the disease progression. While anandamide and its synthesising enzyme display lower levels in Ulcerative Colitis, expression of CB2 receptors and enzymes responsible for synthesis and degradation of 2-AG were increased (from data in 2009). The findings indicate that the CB2 receptor plays a key role in the ameliorating effect of cannabinoids in IBD. The precise mechanism as to how cannabinoids contribute to the improvement of IBD, however, is not clear but by use of experimental models of intestinal inflammation we are able to define a picture on how and at which targets cannabinoids cause improvement of inflammation.

The primary mechanisms through which cannabis exhibits healing properties in Crohn's Disease are its immuno-modulatory and anti-inflammatory properties:

"Cannabinoids have a profound anti-inflammatory effect, mainly through the CB2 receptor ... Studying the functional
roles of the Endocannabinoid System in immune modulation reveals that it is involved in almost all major immune events
... cannabinoids may be used to treat various inflammatory conditions" (Source)

CB1 and CB2 receptors are located at the colonic epithelium, and a protective effect of THC via epithelial permeability is conceivable (Figure 1). Therefore, cannabinoids could enhance epithelial wound closure in the colon, as examined in a study in 2005. The researchers came to the conclusion that CB1 receptors expressed in normal human colon and colonic epithelium are responsive biochemically and functionally to cannabinoids. Increased epithelial CB2-receptor expression in human inflammatory bowel disease tissue implies an immuno-modulatory role that may impact on mucosal immunity. 

Figure 1 - Potential Targets and Mechanisms of Cannabinoids Involved in the Improvement of IBD

Natural and synthetic cannabinoids act via intestinal CB1 and CB2 receptors to regulate epithelial permeability, motility, secretion via the Enteric

Nervous System (ENS), as well as leukocyte migration, recruitment and apoptosis. As the site with the highest CB1 expression (but also some

CB2 expression), the brain may modulate motility, the sensation of pain and unpleasantness, thus positively influencing the inflammatory process.

In 2010, researchers at the University of Naples (Italy), released a study, Cannabinoids and the gut: new developments and emerging concepts, in which it was noted that cannabis was used to treat gastrointestinal conditions that ranged from enteric infections and inflammatory conditions to disorders of motility, emesis and abdominal pain. Anatomical, physiological and pharmacological studies have shown that the ECS is widely distributed throughout the gut, with regional variation and organ-specific actions. It is involved in the regulation of food intake, nausea and emesis, gastric secretion and gastro-protection, gastrointestinal motility, ion transport, visceral sensation, intestinal inflammation and cell proliferation in the gut. Cellular targets have been defined that include the Enteric Nervous System (ENS), epithelial and immune cells.

Figure 2 - The Organisation of the ENS of Human and Medium-Large Mammals

CB1 receptors present in the ENS represent a break that protects it from hyper-stimulation, a situation easily caused by over-expression of inflammatory mediators that activate the ENS during IBD. Therefore, activation of cannabinoid receptors by THC may reduce hyper-motility associated with the inflammation of the gut, researchers reported in a 2012 study, The endocannabinoid system in inflammatory bowel diseases: from pathophysiology to therapeutic opportunity. The reduction of hyper-motility may consequently alleviate diarrhoea producing beneficial effects for the patient.

It should be emphasised that the brain is the major site of CB1 expression and that the presence of CB2 has also been detected in the brain-stem. The use of cannabis in improving inflammation could therefore well include central effects, such as a reduction in pain sensation and relief of nausea and feeling of unpleasantness.

We should consider that other cannabinoids such as cannabidiol (CBD), cannabigerol (CBG) and tetrahydrocannabivarin (THCV), all of them non-psychotropic components of cannabis, have proven anti-inflammatory effects in experimental intestinal inflammation. Their actions should be regarded as additive beneficial effects of cannabis in the improvement of colitis in addition to THC-mediated effects.

There appears to be an established role for cannabis within gastroenterology for the following conditions: abdominal pain, anorexia, colitis, Crohn's Disease, diabetic gastroparesis (delayed gastric emptying), diarrhoea, emesis (vomiting), gastroenteritis and intestinal inflammation at the very least. The ancient use of cannabis in intestinal disturbances and over a decade of animal research, along with the above-mentioned human trials proves cannabis can treat and reduce the symptoms of patients with Crohn's Disease and a multitude of other gastrointestinal problems. Larger trials reiterating these results would go a long way to finally achieving broader acceptance of cannabis as a harmless and most efficacious medicine, and further trials to establish more about the involved mechanisms should reveal promising directions for future treatments.

Adapted from Cannabis Finds Its Way into Treatment of Crohn’s Disease

with Crohns Disease An Infographic 
Treatment of Crohn's disease with cannabis: an observational study

The Endocannabinoid System in Inflammatory Bowel Diseases

Nature Reviews Gastroenterology & Hepatology
Cannabis Patients Guide to Crohn's Disease

Hemp - Food of Life

Hemp, Cannabis sativa L.

Hemp, Cannabis sativa L. is an angiosperm belonging to the cannabaceae family and cannabis genus. Probably one of the first plants to have been cultivated and used by humans throughout history and right around the world. Hemp has been an important plant used for medicine, as fibre for textiles and for the food and nutrition provided by its seed (the fruit of hemp is not a true seed, but an 'achene', a tiny nut covered by a hard shell). Hemp seed oil is particularly nutritious and valued for the numerous health benefits associated with it. Although its fatty acid composition is most often noted, with oil content ranging from around 25-35%, whole hemp seed is additionally comprised of approximately 20-25% protein, 20-30% carbohydrates and 10-15% fibre, along with an array of trace minerals. With a complete source of all essential amino and fatty acids, hemp seed and oil are a complete nutritional source, truly one of nature’s super-foods. In addition, constituents exist within the oil that have been shown to exhibit pharmacological activity.

Hemp seed oil contains linoleic acid (LA) and α-linolenic acid (LNA or ALA) as its major Omega-6 and Omega-3 polyunsaturated fatty acids (PUFA), respectively. These fatty acids comprise the most desirable contents of the oil, especially due to the ratios in which they exist. The 3:1 ratio of LA to LNA is optimal for nutrition. The additional presence of gamma-linolenic acid (GLA) in hemp seed oil ultimately makes its nutritional value superior to all other comparable seed oils.

The myriad of benefits attributable to Omega-3 PUFA include, but are not limited to; anti-cancer, anti-inflammatory, anti-thrombotic, anti-arrhythmic and hypo-lipidaemic (used to treat very high LDL [Low-Density Lipoprotein] or 'bad cholesterol' levels). In addition, a general increase in metabolism (promoting the burning of fat) and lowering of overall blood cholesterol levels has also been observed.

The results of fatty acid analysis are shown in Table 1 and further iterate that the relative ratios and composition of hemp seed oil fatty acids are ideal for human nutrition. As shown, LA concentrations ranged from 52-62% of total fatty acid composition while LNA concentrations ranged from 12-23%. The range of concentrations of fatty acids results from natural variations and factors, including processing and storage methods, as well as age of the samples being tested, could contribute to variability of the fatty acid profile.

As shown in Table 1, hemp seed oil is comprised primarily of linoleic acid (LA) and α-linolenic acid (LNA or ALA) in a 3:1 ratio. Other beneficial natural products such as β-sitosterol, which contributes hypo-cholesterolemic properties (cholesterol lowering) and the tocopherols (a generic term for vitamin E and compounds chemically related to it) which have both anti-oxidant and anti-cancer activities, are present in sufficient efficacious quantities. In addition, measurable amounts of terpenes, including β-caryophyllene and myrcene, cannabinoids such as cannabidiol (CBD) and phenolics were detected, including methyl salicylate (Oil of Wintergreen, a counter-irritant in ointments or liniments for muscle pain, also a flavouring agent) which itself has many health benefits enjoyed by people for centuries. Today aspirin or acetylsalicylic acid, a close relative of methyl salicylate, is one of the most widely used drugs in the world because of its antipyretic (prevents or reduces fever), anti-inflammatory and analgesic properties. Pharmacological effects of methyl salicylate are similar to those of aspirin and it is a beneficial component of hemp seed oil, even if present in trace quantities.

Another component of hemp seed oil with several reported activities is β-sitosterol. Although studies have primarily demonstrated the efficacy of β-sitosterol in reducing hypercholesterolaemia (the presence of high levels of cholesterol in the blood), additional anti-viral, anti-fungal and anti-inflammatory properties have been studied and observed. Within the intestine, phytosterols reduce cholesterol solubility by excluding it from micelles, thereby preventing its absorption. In addition, competition exists between the sterols and cholesterol for uptake into the intestinal mucosa. A quantitative representation of this can be seen in human studies. Patients given 500 mg of cholesterol daily in their diets in addition to 1 g of β-sitosterol showed decreased cholesterol absorption. Mean reduction levels were 42%, demonstrating the efficacy of β-sitosterol even at low concentrations. As shown in Table 1, sterol concentrations based on β-sitosterol were measured in sufficient quantities at 100-148 g/L.

Although β-sitosterol was the predominant sterol, other minor sterols may have contributed to this measurement. At these levels, many of β-sitosterol’s beneficial qualities will be obtainable. β-Sitosterol seems to be particularly effective in cholesterol uptake inhibition, especially when delivered through dietary fats. No appreciable decreases in efficacy were observed, even with long-term administration. In addition, lack of toxicity and little, or no side effects have been attributed to β-sitosterol, making it an attractive option for long-term cholesterol reducing therapy. Although not studied as extensively as its hypocholesterolemic properties, relevant anti-viral and anti-inflammatory activities of β-sitosterol have been shown.

The presence of several terpenes were confirmed in hemp seed oil, the most abundant of which were β-caryophyllene and myrcene, found at 740 mg/L and 160 mg/L, respectively (Table 1). Terpene compounds, in general, are primarily found in the essential oil of cannabis rather than in the hemp seed oil as a result of their production in the glandular structures (trichomes) on the aerial portions of the plant. These compounds are a component of the characteristic aroma of cannabis and may impart some of these properties to the hemp seed oil. Additional benefits may be provided to the oil as well. Some previously noted pharmacological properties of β-caryophyllene would include anti-inflammatory and cytoprotective (protects cells against harmful agents) activities which may too be active in the hemp seed oil. In addition, it has been reported that myrcene exhibits anti-oxidant properties. The presence of β-caryophyllene and myrcene, even if only present as contamination components, add beneficial value to an already nutritionally important food product.

Glandular structures (trichomes)

The production and storage of both CBD and THC occur in the glandular structures of the plant and the concentrations of CBD are typically much higher than THC in most fibre and oil varieties of hemp.
Cannabidiol (CBD) has been shown to possess several desirable pharmacological properties. Although the levels of CBD detected in the oil were low at 10 mg/kg, its presence is significant because it has documented anti-convulsant, anti-epileptic and anti-microbial properties. CBD has been reported to reduce tremors in dystonic movement disorders with minimal side effects. Patients receiving doses of CBD ranging from 100-600 mg/day had tremor reductions of 20-50%. Analgesic and anti-inflammatory potential has been reported with CBD as well as anti-microbial activity, specifically, inhibiting growth in gram-positive bacteria such as Streptomyces griseus and Staphylococcus aureus. These organisms are particularly sensitive to extracts of cannabis in slightly acidic culture medium even at dilutions as low as 5 ppm. Terpenoid compounds have been identified as present in hemp seed oil. Health benefits may be gained from their presence even at concentrations similar to that of CBD. The major terpenes identified have been cited as having anti-inflammatory, anti-allergenic, and cytoprotective pharmacological properties.

As a result of the change in dietary habits with the intake of trans fatty acids increasing dramatically, studies have shown conclusively that trans fatty acids increase total cholesterol levels and diminish the levels of high density lipoprotein (HDL, 'good' cholesterol). By supplementing the diet with high levels of unsaturated cis* fatty acids (increasing the levels of HDL in the body while decreasing bad cholesterol) some of the negative effects can be reversed. With respect to modern diets, the amount of LA consumed compared to the amount of LNA consumed has increased exceptionally in the past 100-150 years.
*cis fatty acids - the bend in the carbon chain is much more pronounced in the cis isomer compared to the trans isomer. For this reason, cis fatty acids do not solidify as readily as trans fatty acids. Due to the larger bend, the cis isomers cannot line up next to one another in as ordered a fashion as the trans isomers. While trans fatty acids are uncommon in natural fatty acids, they form readily when polyunsaturated fatty acids from plants are 'partially hydrogenated' chemically (done commercially to make plant fatty acids more solid and improve shelf-life). Epidemiological studies correlate consumption of trans fatty acids with increased risk of heart disease.

This disparity has disrupted the proper balance of dietary essential fatty acids that is considered nutritionally optimal. In addition to the lack of these essential fatty acids in the diet, factors such as stress and disease weaken the enzymatic activity that promotes the conversion of LA to GLA. Therefore, a supplementation of LA can be helpful to alleviate this potential deficiency. In an ideal diet, the daily consumption of fats should not exceed 15-20% of total caloric intake. Approximately one-third of these fats should be the essential fatty acids in their proper ratio. For a 2500 calorie/day diet, LA intake should be 9-18 grams/day, and LNA intake should be 6-7 g/day. This goal can easily be accomplished through the daily consumption of 3 to 5 tablespoons of hemp seed oil.

World Health Organisation Dietary Recommendations

Although these are the ideal amounts to maintain a healthy, balanced diet, certain stresses to the body warrant increased consumption of essential fatty acids, particularly the Omega-3 PUFA such as LNA. Omega-3 PUFA have been reported to have an inhibitory effect on cancer and tumour growth. Increased consumption of Omega-3 PUFA have not been shown to exhibit any negative side effects, but their beneficial qualities have been repeatedly confirmed. In addition to their anti-cancer properties, Omega-3 PUFA have been shown to lower blood pressure and blood cholesterol levels, help normalise fat metabolism and decrease insulin dependence in diabetics, increase overall metabolic rate and membrane fluidity and exhibit anti-inflammatory properties, specifically with regard to relieving arthritis. The benefits of Omega-3 PUFA are not only present when taken in large quantities but the regular intake of recommended levels (2-2.5% of caloric intake/day) can be sufficient to provide many of its nutritional qualities.

In addition to all of these positive health benefits there seems to be a complete lack of negative effects from its consumption. To date, there has been no reported cases of toxicity from the ingestion of hemp seed oil. Toxicity has also not been observed with any of the other constituents that were found as 'contaminants', which are primarily the cannabinoids. One reason for the lack of negative side effects from excessive ingestion of hemp seed oil is specifically related to the ratio of LA:LNA. Because most oils do not contain the optimum ratio of Omega-6 and Omega-3 PUFA, they tend to promote the accumulation of metabolic intermediates that in turn hinder fatty acid metabolism. The properly balanced hemp seed oil does not promote an over-accumulation of certain metabolic products and all of the fatty acid metabolic pathways have the necessary intermediates to work efficiently regardless of the quantities consumed.

Resources:

Journal of Nutraceuticals, Functional & Medical Foods
Fatty Acids and Triacylglycerols
The Composition of Hemp Seed Oil and Its Potential as an Important Source of Nutrition
Hemp ... Seed Oil: Analytical and Phytochemical Characterization of the Unsaponifiable Fraction
American Chemical Society
Hemp seed oil: A source of valuable essential fatty acids
Study of Thiosemicarbazone Derivative of Essential Fatty Acid
Occurrence of "omega-3" stearidonic acid ... in hemp (Cannabis sativa L.) seed
International Hemp Association

Hempcrete

Hemp mortar was discovered in bridge abutments (Merovingian bridges) in France built in the 6th century (the Merovingians ruled the Franks in much of the territory then known as Gaul). Since its rediscovery, and redevelopment in France in the 1980's, it has seen growing use as 'hempcrete' (hemp lime composite) across Europe, where hemp cultivation was never criminalised. France is Europe's biggest producer of hemp, but only about 5% of hurds are used in the building sector. In 2010/2011 the total area cultivated with hemp in the EU was about 11,000 ha, a slight decline from the previous year. Given it has already survived so many centuries, people expect hempcrete buildings to have a long life and across Europe and the United Kingdom (UK), hundreds of buildings now use hempcrete, including a seven-story office tower in France and a Marks and Spencer department store in the UK.

The host of the UK television series 'Grand Designs' waxed lyrical about hempcrete for the documentary 'Bringing it Home' (2011) during construction of over 40 hempcrete homes at The Triangle, Swindon, Kevin McCloud said; "I look at the range of materials out there ... I cannot find one to match hemp ... such a low environmental impact, that can be grown locally and harvested with minimum input in a matter of just a few months, it's an incredibly expedient building method" he said. "This field of hemp is absorbing all this CO₂ and dirt and we are going to build houses with it ... the project manager here on site said to me he loved the material ... instead of pouring out heavy, wet, toxic, caustic concrete, it would instead pour out this sort of fluffy, lightweight stuff that was like sawdust; it didn't require any power tools ... so all we had was buckets and barrows and blokes and because there were no power tools there were no cables everywhere, and it actually makes for a very, very healthy, very safe building site. Hemp, it's a very, very builder-friendly material. I mean, you know, it's a no-brainer." Yes, building with hemp seems a complete no-brainer in the current world climate.

In 2014 the Hemp Industries Association (HIA) in the United States (US) estimated the total retail value of all hemp products sold in the US at $620 million (a 22% increase). Sadly for the US hemp industry, all the raw hemp materials were imported from other countries. Over 30 countries grow hemp, including Spain, Austria, Canada, China, UK, France, Russia and Australia. 

Though it lacks the structural stability its name might suggest, hempcrete does provide natural insulation and is virtually fireproof. In 2015, according to The New York Times, hemp-based building materials could usher in a new era of 'green' building in the US. While hemp has had a long history as a fibre used in ropes, sails and paper products - US Presidents Washington and Jefferson both grew it - a small number of US entrepreneurs have turned to hempcrete. 

Hempcrete is a bio-composite made of the inner woody core ('shiv', a short length, stalk by-product) of the hemp plant (bast and hurd fibres) mixed with a lime-based binder. The shiv has a high silica content which allows it to bind well with lime, a property unique to hemp among all natural fibres. Lime protects the shiv from biological decay, mainly through its ability to wick water away, its high alkalinity, as well as providing essential fire resistance.

Hempcrete is environmentally sustainable due to:

a) Being a carbon-sequestering building material from the growth of the hemp crop to the carbonation of lime in the walls for the life of the building. The breakdown of the carbon sequestration is as follows:
In one (1) cubic metre of hempcrete, emitted CO₂ is;

110kg of hemp hurd =  -202 kg (CO₂ absorbed)

220 kg of lime binder = +94 kg (CO₂ released)

Total sequestration = -108 kg/m³ of wall built

b) Reducing energy consumption due to excellent insulation and airtightness. There is little heating or cooling loss from a hempcrete building which means constant energy output to cool or warm the building is not required. Hempcrete has low effusivity and high thermal inertia, it does not take as long to heat and once heated will slowly release heat when the temperature drops, at night, so a heater is rarely needed.

c) Being fully recyclable; any waste on-site can be re-used in the next mix. If a building is being demolished, the hempcrete can be easily broken down and re-used in a new build. As landfill, being a natural product, it will break down over the course of time and add lime and organic matter to the soil.

CaCo₃ (limestone) goes the full circle from being broken down to carbonation when hempcrete is formed. 

As the hempcrete hardens from carbonation, it will eventually petrify the hemp and form limestone.

A lightweight, cementitious insulating material weighing around an eighth of comparable concrete (fully cured hempcrete blocks float in water) it is not used as a structural element, only as insulating infill of walls, roof and under-floor as part of a timber-framed building with all loads carried by internal wood stud framing. Hempcrete is ideally suited to low-rise construction and offers good thermal and acoustic performance with the ability to regulate internal relative humidity through hygroscopic material behaviour, contributing to healthier building spaces and providing effective thermal mass.

Hempcrete is mixed in a concrete or mortar mixer for 1-2 minutes and 'hand delivered' into the wall cavities. Walls are formed with temporary wooden or plastic 'shuttering' for the inner/outer surfaces. Hempcrete is lightweight and can be moved easily about in buckets and passed 'bucket-brigade' fashion to workers filling the cavities. Site clean-up is easy too, simply till it into the soil! Hempcrete is finished with an exterior hard render coating about 20 mm thick and further protected with a final coloured topcoat; the end result is stucco-like. The interior can be left natural or finished with lime plaster for a more traditional look. Hempcrete is toxin-free, airtight yet breathable, unaffected by mould and pests and practically fireproof. Best of all, hempcrete is a sustainable building material because hemp can be grown and replenished relatively quickly.

Hempcrete restoration work in the UK

So why haven't we seen it adopted in the US and Australia just like in Europe? Prohibition! While hemp is legal to use and import, the US has been prohibited from growing it for nearly 70 years, purely because it resembles its psycho-active cousin 'marijuana'. President Obama signed the Agricultural Act of 2014 which removed federal restrictions on growing industrial hemp, good news for US growers, although it will take time to cultivate the plant. Until then the US must rely on hundreds of millions of dollars worth of hemp imports (mostly from Canada and China) to meet its growing need for hemp. Hemp grown legally in Europe, the UK and Canada through a system of licensed growers produces seed certified low in THC. Currently, added shipping reduces the carbon-negative feature of hempcrete in North America and adds to production costs. In 2015, Hemp, Inc. released a video update on the progress of its decortication plant in Spring Hope, North Carolina. According to the footage, Hemp, Inc.’s decortication line is about 60% complete. To date, there are only five decorticators of this magnitude in the world. "Once in operation, the American hemp farmers will have access to the largest natural fibre manufacturing and processing facility in North America for their crops", said Bruce Perlowin, CEO of Hemp, Inc. 

WHERE IS HEMP GROWING IN THE US IN 2015?

The number of acres of hemp planted by US farmers has increased over 1,000% in 2015, as compared to the number of acres planted in 2014, the first year of legal hemp growing in the United States. The green squares in the map below represents hemp farmers who have registered with their state.







It’s been legal to grow hemp in Canada since 1998, though farmers still need to apply for a license and authorisation from Health Canada. In 2009, 9,725 ha of hemp were planted and it is expected that hemp will continue to contribute more than $100 million to Canada's economy annually. Several Canadian companies have advanced plans to start developing the fibre side of hemp but the $30 million cost to build a processing plant has been a barrier. Alberta Innovates has a small processing plant where they are testing production and manufacturing options. “We are just at the verge of seeing hempcrete buildings across the province and beyond”. Canadian entrepreneurs will have to act soon, though, if they don’t want to deal with American competition. Several US states have already started to relax regulations, and earlier this year a bill was introduced in the US Senate that seeks to end the federal ban on cultivation entirely. The bill is currently in committee.

Australia's prohibition on growing industrial hemp was lifted in the late 1990's, but farmers are restricted to growing fibre and construction materials and politics has prevented them from gaining access to booming hemp food markets. In 2014 Australian hemp producer Ecofibre said of the industry: "What we are producing presently is just low-level, low-value market material such as pet bedding, horse bedding, erosion control mediums, oil spill containment products, garden mulch - you know, basic things like that ... there's lots of products we could get to eventually, but ... the industry isn't at that stage yet. It's hampered". 

Growing industrial hemp under license is already legal in Queensland, New South Wales, Victoria, Tasmania and Western Australia. However, the industry is very restricted because of archaic law/s not allowing hemp for human consumption (only two countries ban it, Australia and New Zealand) based on missguided concerns by law enforcement that hemp consumption could somehow affect roadside saliva drug testing or would 'send the wrong message' about Cannabis consumption. 

Hemp is Cannabis sativa, a member of the Cannabaceae family. Cannabis is the plant genus, sativa (Latin for 'cultivated') is the species. A high-resin crop, Cannabis is generally planted about 1.2-1.5m (four to five feet) apart and mostly used for its medicinal/therapeutic leaves and buds. Hemp, however, is a low-resin crop, generally planted about 10 cm (four inches) apart, mostly used for its versatile stalk and seed. Different types of Cannabis are classified as strains and different kinds of hemp are classified as varieties and cultivars.

Tasmanian hempcrete house under construction

In New South Wales (NSW) the introduction of a licensing scheme under the Hemp Industry Act 2008 was designed to allow farmers to grow low THC hemp crops for fibre and oil production while limiting the risk to law enforcement. It is an offence under the Drug Misuse and Trafficking Act 1985 to possess hemp unless it's cultivated or supplied under authority. Those wishing to grow should be aware that an environmental assessment and approval process applies in addition to NSW Department of Primary Industry’ licensing requirements. Low THC hemp plant material cannot be fed to livestock.

Queensland has allowed industrial production under license since 2002, with issuance controlled under the Drugs Misuse Act 1986. If you intend to grow or research industrial hemp, you must have a license. All activities carried out under a license are subject to monitoring at the licensee’s expense by inspectors who, among other things, sample plants before harvest to test for THC content.

In Western Australia (WA),  The Department of Agriculture and Food acts as the Registrar for the Industrial Hemp Act 2004. This legislation enables licensees to cultivate, harvest and process industrial hemp on a commercial scale. AGWEST Plant Laboratories handles the compliance side of the licensing process including inspection and sampling of crops and reporting to the Registrar. The Industrial Hemp Act 2004 allows a person wishing to participate in the industry to apply for a license, usually valid for three years, and be heavily scrutinised to ensure suitablity and eligibility to participate in the industry.

In Tasmania, industrial hemp industry regulations include five year licenses. In January 2015 the Tasmanian Government announced reforms to simplify the regulation and support growth in the industry. Under the new laws, the allowable THC content will rise from 0.35% to 1.0%, bringing it in line with New South Wales, Queensland and the Australian Capital Territory. Tasmanian research data from the Forthside Research Station showed that up to 15 t/ha of dry stem can be produced from one planting. It is also possible to grow two crops in the same season if an early (September) and a late (December) sowing are carried out on the same site. 

In 1998, Victoria became the first Australian State to pass legislation permitting growers, under license, to grow industrial hemp. However, since then, the industry has not progressed. Hemp is defined under the Drugs, Poisons and Controlled Substances Act 1981 as a narcotic plant. Persons wishing to grow industrial hemp must obtain authorisation from the Department of Environment and Primary Industries (DEPI) to do so.

Ruth Trigg, IHA SA and Greens
MP Tammy Franks 

The South Australia Controlled Substances Act lumps all types of Cannabis together too, but still prohibits all of them, effectively preventing any form of industrial hemp cultivation. A special license was given in 1995 and trial crops were planted in South Australia (SA). In 2015, in South Australia, hemp is still not legally grown. Legalising hemp to make clothes, building materials and beauty products could be part of the solution to South Australia’s looming post-Holden manufacturing crisis said the newly formed Industrial Hemp Association (IHA) of SA and Greens MLC Tammy Franks. “It can revolutionise the building industry using the qualities of hempcrete; fire retardant, insulation, acoustics, absorbing CO2 for the rest of its life, and for ease of use as a pourable slurry.” The Manufacturing and Innovation Minister revealed in State Parliament that he was planning to meet with the Industrial Hemp Association of SA to discuss its proposal to legalise hemp production in the state.

Hemp itself is a beneficial crop requiring no fertiliser, weed killer, pesticide or fungicide. It grows so thickly that weeds cannot grow. Farmers grow it in rotation with other crops such as barley or rye. The crop following hemp requires no weed killer because hemp drives the weeds out.

It is encouraging to see a trend in some developed countries of accepting the use of energy and resources to fuel a wasteful and profligate construction industry is way beyond the ability of the planet to continue to support. Mass materials like cement and concrete cause significant pollution, use a lot of energy and non-renewable resources. Many of the materials such as insulation and finishes contain toxic chemicals like brominated fire retardants which can seriously damage our health as well as the ecosystem. It has long been recognised that buildings and their use contribute significantly to CO₂ emissions however it seems there are two main approaches to creating a lower impact on the environment. There are those focussed on getting mainstream construction to be more energy efficient, even though they still rely on high-embodied energy products such as cement, bricks, concrete and steel. This focus is based on retaining the same style of construction using the same materials with more insulation (petrochemical-based) and solar technology to reduce the impact. It would seem the intent is to appease the environmental conscience without pain. In the UK, the construction and use of buildings accounts for over 50% of the carbon dioxide produced. Studies have shown that up to 200kg of CO₂ is emitted in the production of each square metre of walling for houses alone, equating to 40 tonnes for the walls of a typical house using double brick. The other approach has been to look at low impact alternatives that also are healthier and less polluting in both manufacture and construction technique.

Hemp Cottage, County Down, Northern Ireland

Although the US still has a long way to go towards ending Cannabis prohibition, it's both encouraging and inspiring to see how far they've come in a relatively short amount of time. Four states and Washington DC have legalised Cannabis, two dozen states offer legal medical 'marijuana' and hemp production could be a game-changer across numerous industries while helping to keep the planet healthy. As government policy becomes increasingly concerned with reducing carbon emissions and finding more efficient ways of meeting carbon reduction targets, it seems possible that hempcrete can make a major contribution to this, offering a genuinely zero-neutral solution to sustainable construction. As for Australia? The people are still preparing for the revolution to start, the hemp revolution, that is.


Resources included; Hempcrete Could Be Putting the Green in Green Building, What is Hempcrete,  National Hemp Association, Hempcrete, Politics of Pot, Hempcrete Sustainability, Hempcrete Best Concrete, Hemp Now Seen As Growth Industry, DPI NSW Summer Crops/Fibres, Qld Industry Agriculture Niche Hemp, Industrial Hemp Queensland, Industrial Hemp Western Australia, DPIW Tasmania, New Laws Aim to Streamline Tasmanias Industrial Hemp Industry, Hemp Victoria, DPI Victoria, Australian Hemp