Marijuana: A Healer Or A Killer?

For some, marijuana is, just like any other herbs, Nature’s gift to man. For others, marijuana is a toxic and addictive naturally occurring herb that should be avoided at all costs.

The debate over the health benefits of marijuana has been long standing, and up to today, opinions are still divided as to whether or not marijuana should be used routinely, just like any other herb. The point of this article is not to state whether or not or why or why not marijuana should or shouldn't be decriminalized. We are simply going to look at what marijuana is, chemically and medically speaking, and in that sense we will dissect its effects on human health, be it positive or negative.

What is Marijuana?

Also known as cannabis, marijuana is a psychoactive herb extracted from the plants Cannabis sativa, Cannabis indica, Cannabis ruderalis. It contains at least 483 compounds, out of which 83 are cannabinoids. Cannabinoids are chemical compounds which act on the cannabinoid receptors located in the human body (in the brain and in the immune system). The body itself releases a certain amount of cannabinoids, but those that are exogenous can be obtained from plants such as marijuana (phytocannabinoids).

How does Marijuana work?

The active component of marijuana is called Tetrahydrocannabinol (THC), and works similarly to our natural endogenous cannabinoids. 

The Endogenous Endocannabinoid system

The body possesses a wider variety of cannabinoids receptors thoroughly distributed in the central and peripheral nervous systems. The two main categories of cannabinoid receptors are CB1 and CB2. They are found in higher quantities in areas involved in pleasure, memory, thought process, concentration, movement and balance, sensorium and perception, food intake, general metabolism and energy processing. These body organs include the hypothalamus, the nucleus accumbens, the vagus nerve, the brainstem (pons and medulla oblongata), the digestive system, the liver and the adipose tissue.

With that said, when someone smokes marijuana, the THC that it contains is transported through the blood and binds to the cannabinoid receptors. Given that THC is released in high contents, the cannabinoid receptors are over-stimulated, which creates the “marijuana high” that marijuana consumers usually experience. Marijuana effects are experience faster when smoked compared to when ingested, because inhalation allows a quicker and faster diffusion of THC in the blood stream, compared to digestion (that takes several hours to be completed and reduce the bioavailability of the drug)

Effects on Body Systems

Memory

It is commonly conceived that people who use marijuana experience short term memory defects. However, studies performed on mice treated with THC revealed impaired long-term memory, due to the suppression of the hippocampus (part of the brain responsible of consolidating long-term memories). However, a recent study demonstrated that treatment of rats with high dose of THC could stimulate the growth of hippocampal neurons. With that said, the effects of THC on memory truly depends on the dose, and possibly the type of neurons (whether excitatory or inhibitory) affected.

See Also: Marijuana: Pros And Cons

Appetite

Endocannabinoids directly bind to CB1 receptors in hypothalamic nuclei to stimulate appetite. A study performed on mice revealed that mice whose CB1 receptor was knocked out were seen to be less hungry and considerably leaner compared to wild mice. Additionally, the endocannabinoid receptors affect taste perception by increasing the intensity of neuronal signaling in the taste cells. Lastly, by stimulating the receptors located in the nucleus accumbens, endocannabinoids triggers the reward and pleasure that we experience when eating food.

Cannabis Effects On Body Functions

Social Behavior And Anxiety

A study performed on mice showed that people with prolonged exposure to cannabinoids were found to have decreased social interactions and increased aggressive behavior. This can however depend on the type of cannabinoid receptors affected. For instance, cannabinoid receptors that respond to glutamine (excitatory neurotransmitter in the brain) are involved in increased social interaction and decreased aggressive behavior, and for the cannabinoid receptors that respond to GABA, (inhibitory neurotransmitter), it is quite the opposite.

Energy and general metabolism

The endocannabinoid system also regulates our overall body metabolism through its effects on peripheral organs such as the liver, adipose tissue, digestive system, pancreas and skeletal muscles. Henceforth, it may play a role in metabolic diseases such As diabetes, obesity and atherosclerosis.

Pain Regulation

The cannabinoid system is also thought to regulate pain perception and transmission. This is mostly done at the level of the spinal cord. By stimulating the cannabinoid receptors on the sensory limb of the spinal cord (called the dorsal horn) the endocannabinoids increase the release of noradrenaline, which in turn prevents the transmission and processing of pain impulses in the dorsal root ganglion. This is one of the reasons why cannabinoids are sold in pharmacy as potent analgesics, or as part of herbal supplements formulas.

Sleep

Ensdocannabinoids induce and promote sleep. They increase our brain levels of adenosine, which is a chemical that has been shown to decrease arousal and increase sleep. Cannabinoids also increase the episodes of REM sleep. In studies made of rats, it was shown that their brain levels of endocannabinoids were higher in the day (which is when rats are the least active, since they are nocturnal).

Reproduction

Studies have demonstrated that exogenous cannabinoids can either increase or decrease the likelihood of implantation in females. For instance, if one’s levels of endogenous cannabinoids are already low, then taking exogenous cannabinoids can improve the chances of implantation. However, if the endogenous cannabinoids are high, exogenous cannabinoids would decrease the chances of implantation. The link between cannabinoids and implantation is justified by the fact that during embryogenesis, the embryo develops cannabinoid receptors to facilitate recognition by endogenous cannabinoids.

Immune function

See Also: Marijuana and the Immune System

They also favor the movement of lymphocytes into their functional zone, as well as the increase of immunoglobulin levels (particularly IgM which is the immunoglobulin released first in acute inflammation).

With all that is said and done, the body would not produce something that we wouldn't need to function. Cannabinoids have their role and part to play in several body functions, the most important being the maintenance of adequate metabolism, regulation of digestive functions and efficacy of the immune system. However, some effects of cannabinoids (more negative than positive) are dose dependent, and those are surely the unwanted effects that we are being warned about these days.