Strains of Cannabis explained
Each cannabis plant has unique characteristics which effects its therapeutic benefit to patients
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Cannabis comes from a species of plant called Cannabis sativa. Wild-growing cannabis plants have different characteristics throughout the world, due to climate and geography. In addition, plants with specific strains have been selectively grown.
Flowering plants with active ingredients are favoured for medical use, while tall, fibrous plants are grown to make hemp textiles.
Over time, these factors resulted in groups of cannabis plants with unique characteristics. People call these groups “strains”, however, more accurate scientific terms are “subspecies”, “varieties” and “cultivars”.
How Do Cannabis Strains Differ?
Cannabis strains usually have distinct leaf shapes, branching patterns and heights. Scientists have identified over 500 natural chemicals in the cannabis plant, including cannabinoids, terpenes and flavonoids. Cannabis strains have different concentrations of these chemicals, which leads to varying effects in the human body.
Cannabinoids are the most common type of chemical in Cannabis sativa. They interact with the endocannabinoid system in the human body and are responsible for most of the medical and recreational effects of cannabis. The two most researched cannabinoids are Δ9-Tetrahydrocannabinol, THC, and Cannabidiol, also know as CBD.
THC is the most-researched cannabinoid, and is responsible for the pleasurable feeling or “high” from recreational cannabis. Research indicates that THC may be useful for pain relief and as a muscle relaxant, appetite stimulant and antispasmodic.
Unlike THC, CBD has no mind-altering effects. The medical community is interested in CBD as a potential anti-seizure, anti-nausea and pain relief medicine. CBD may also dampen some of the unwanted effects of THC when the two are taken together.
CBC is more common in young plants and decreases over time. CBC may have anti-inflammatory, antimicrobial, antidepressant and pain-relieving properties.
Cannabis plants usually have very low concentrations of CBG, however, growers have been able to breed strains with higher amounts. Research suggests that CBG may have muscle-relaxing, antidepressant, antifungal and pain-relieving properties, as well as possibly being useful for psoriasis.
THCV is mainly found in African cannabis plants. THCV may have anti-inflammatory and pain-relieving properties.
CBDV has a similar structure to CBD and is thought to have anti-seizure properties.
CBN is a by-product of THC, which is usually found in aged cannabis samples. CBN may have anti-seizure, anti-inflammatory and antimicrobial properties.
Cannabinoids: THCA and CBDA
Although THC and CBD are the best-known cannabinoids, living cannabis plants do not produce them in significant quantities. Rather, the plant makes acids called tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA), which turn into THC and CBD after harvesting.
Recent research has revealed that THCA and CBDA are more than just inactive precursors; in fact, they have properties of their own which may be useful in medical treatment.
As cannabis plant material dries out, a natural chemical reaction called decarboxylation converts THCA and CBDA into THC and CBD. This happens even faster when cannabis is heated, for example, by smoking or vaporizing.
People often refer to THC and THCA or CBD and CBDA as one and the same, because cannabis is typically dried or heated before use and almost all of the acid content will have converted to THC and CBD. However, if cannabis is not heated or dried during processing, high levels of THCA and CBDA will be present with very little THC and CBD.
Tetrahydrocannabinolic Acid (THCA)
Unlike THC, which is responsible for the “high” from cannabis, THCA does not have any mind-altering properties.
Research suggests that THCA may have anti-inflammatory and anti-nausea properties, as well as possibly protecting against neurodegenerative disease and inhibiting cancer cells.
Cannabidiolic Acid (CBDA)
Like CBD, CBDA does not have mind-altering properties. Research on CBDA is limited at present, however, some studies indicate that it may have antibacterial and anti-nausea properties as well as possibly inhibiting cancer cells.
Terpenes are essential oil compounds used by plants to repel insects and grazing animals. Terpenes give cannabis its characteristic smell and flavour. Some experts believe that terpenes can modify or enhance the effects of cannabinoids, however, research is still limited and no clinical trials have looked into this topic.
Research suggest that limonene may have anti-anxiety and antidepressant properties. Limonene is also present in lemon and other citrus fruits. Also thought to cause alertness.
Pinene is thought to aid memory and may reduce short-term memory problems caused by THC. As the name suggests, it is also found in pine trees. Also thought to cause alertness.
Myrcene is thought to have anti-inflammatory, anti-anxiety, and pain relief properties. It also occurs in thyme, parsley and hops and may help with sleep.
Linalool is thought to have anti-anxiety, anti-inflammatory, anti-seizure and pain-relieving properties; it may also help with sleep. Linalool is also found in lavender.
Caryophyllene is an anti-inflammatory substance, which is also found in black pepper.
Scientists have identified around 20 different flavonoid compounds in cannabis so far. Flavonoids protect plants from oxidative stress and may also be beneficial to human health. Some studies suggest that flavonoids have anti-inflammatory properties and reduce the risk of cancer, cardiovascular and neurodegenerative diseases in humans, however more research is needed to confirm this.
Sativa and Indica
Although botanists do not agree on the number of cannabis subspecies and varieties that exist, people often use the names “sativa” and “indica” to distinguish between strains of cannabis with opposite effects. Sativa is described as “uplifting and energetic”, while indica is “relaxing and calming”.
However, this naming system is not reliable as it does not provide any information about the chemical content of the plant. Cross-breeding is so widespread that it is not possible to guess the chemical content of a plant from its leaf shape or branching pattern. Furthermore, factors such as soil content and external environment can alter the potency of plants grown in different conditions.
The only way to truly predict the effects of a cannabis strain on the human body is to measure the cannabinoids, flavinoids and terpenes present.