THC is the main psychoactive component in cannabis. It interacts with the body’s endocannabinoid system to produce many psychological and physical effects, some of which are beneficial and others that are undesirable.
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Research continues into how exactly cannabis consumption affects the body via this system, with many studies exploring how this system can be exploited for its beneficial effects.
The discovery of the endocannabinoid system
Decades of research into how cannabis impacts the body has resulted in scientists gaining a firm understanding of the components of cannabis, and how they impact the brain and body via the newly discovered endocannabinoid system.
The endocannabinoid (EC) system was named due to its interaction with the active ingredient of the cannabis plant, delta-9-tetrahydrocannabinol (THC).
The system, which is triggered by the consumption of cannabis products, governs a number of essential bodily functions and processes such as sleep, appetite, mood, memory, reproduction and fertility, energy balance and metabolism, analgesia, stress response, thermoregulation, and potentially many more.
The body produces natural chemicals known as cannabinoids that interact with THC in cannabis. The THC molecules impact the system’s receptors and moderate the functions associated with the system.
This alteration of the EC system can lead to the characteristic effects of cannabis consumption, such as increased appetite and memory deficits, and it is also important for understanding how cannabis use can make someone more at risk of accidents, and also explain how addiction can occur.
Below we discuss how the endocannabinoid system works, and how cannabis use interacts with the system to influence various functions and processes of the body.
How does the endocannabinoid system work?
The EC system encompasses endocannabinoids, receptors, and enzymes. All three work together to regulate a number of essential bodily functions.
Research has uncovered the existence of two types of cannabinoids, known as endocannabinoids because they are produced by the body, called anandamide (AEA) and 2-arachidonoylglyerol (2-AG).
Usually, the body produces its required level of endocannabinoids which then bind to the EC’s receptors throughout the body in order to trigger certain actions of the EC system.
The EC system has two main types of receptors, the CB1 receptors of the central nervous system (CNS), and the CB2 receptors of the peripheral nervous system.
The effects of the endocannabinoids binding to these receptors are dependent on which endocannabinoid binds to the receptor and the location of the receptor.
The system’s enzymes play a vital role in downgrading the endocannabinoids once their function has been carried out.
Like the body’s naturally produced endocannabinoids, THC interacts with the EC system by binging with the CB1 and CB2 receptors.
This allows it to induce a myriad of effects on both the body and mind. For this reason, cannabis has been the subject of much research investigating its potential therapeutic effects. So far, cannabis has been seen to be useful in reducing pain and stimulating the appetite, which is valuable in the treatment of some illnesses, however, it has also been shown to initiate undesirable responses such as increased paranoia and anxiety.
Below we discuss how THC impacts various key bodily processes via the EC system, although, this is not an exhaustive list.
For decades THC has been known to impact sleep patterns, with studies back in the 1970s elucidating how it reduced eye movement during and shortened the time spent in REM (rapid eye movement) sleep.
Research into exactly how cannabis use alters sleep patterns via the EC system is still in its early days. However, it is known that the EC system is heavily involved in sleep regulation, with increased endocannabinoid signaling in the CNS initiating sleep.
Cannabis use has long been associated with an increased appetite. Recently, studies have uncovered why this is one of the most notable effects of cannabis use. THC activates CB1 receptors which are implicated in many mechanisms.
To begin with, activation of CB1 can reduce the body’s levels of peptide tyrosine (PYY), which has the effect of increasing ghrelin, which increases the appetite. In addition, CB1 activation also turns on the mTOR (mammalian target of rapamycin) pathway, which also increases ghrelin levels, thus increasing the appetite.
Finally, CB1 activation also triggers the proopiomelanocortin neurons (POMCs) which are known to increase appetite via the secondary pathway which is activated by THC.
Through activation of the CB2 receptors on immune, THC reduces the body’s pain-inducing reaction to injury. This is known as an anti-inflammatory response, and it is often triggered by bacteria, trauma, toxins, heat, and chemicals, which is why it is important in the treatment of illness and injury.
New research is coming to light revealing the long-term effect that cannabis use has on the stress response.
Studies have shown that long-term users in comparison with non-users have a reduced stress response. While usually, the body releases cortisol in response to stressful situations, long-term cannabis users do no show this response.
As too much cortisol can be harmful to the body, this effect of THC on the body is important in considering new therapeutic approaches to those under chronic stress. However, the underlying mechanisms producing this effect are still under investigation.
Research into THC’s effects on the EC system continues, and we can expect studies to continue to uncover the mechanisms of how THC impacts certain bodily processes. This research is likely to prove invaluable in developing the use of cannabis and THC in therapeutic approaches.
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