Marijuana in the Body
People have been consuming marijuana for medical, religious, and recreational purposes for millennia. Today, some people use marijuana to treat chronic pain, anxiety, insomnia, epilepsy, glaucoma, and an variety of other health concerns, while others use it recreationally to induce a state of euphoria, help with creativity, and generally make life more interesting.
While over half of all Americans have experienced the effects of marijuana first-hand, few are aware of exactly how it works. Most of the common misconceptions about marijuana, including those that drove the FDA to label it a Schedule I drug back in the 1970s, stem from ignorance of its generally benign physiological effects. This article will offer an in-depth introduction to marijuana’s effects on the mind and body, offering some insight into how this popular yet often misunderstood plant produces both its physical and psychotropic effects.
The Endocannabinoid System
It’s general knowledge that consuming marijuana produces a range of physical and psychological effects, but the exact biochemical mechanisms to thank for those effects have only been recently researched and understood. Before the discovery of the endocannabinoid system, most researchers believed that marijuana produced non-specific biochemical effects in the brain, similar to those produced by drugs like barbiturates. This misconception helped to fuel unwarranted fears of marijuana’s potential health risks in the 20th century.
Now, researchers know that the cannabinoids found in marijuana bind only to the receptors in the body’s endocannabinoid system. That’s what produces the unique physiological effects associated with getting high. It’s also what makes marijuana such a panacea for medical researchers.
But how, exactly, does the endocannabinoid system work? Why do different strains of marijuana produce different effects? And why aren’t people just walking around high all the time off the endocannabinoids produced by their own bodies? The answers are complicated, so let’s start from the beginning.
A Quick Lesson in Neuroscience
The brain is made up of billions of long cells called neurons that are clustered together with small spaces between them known as synapses. To bridge these synapses and allow communication between the neurons, the brain uses what is known as neurotransmitters.
Neurotransmitters are chemicals that travel between neurons, carrying information and instructions. They attach to the neurons via receptor sites. Endocannabinoid receptors are just one type of receptor, and they’re not just found in the brain. They’re spread throughout the entire human body.
The endocannabinoid system refers not just to the relevant receptors but also the chemicals (endocannabinoids) themselves and the enzymes that help break them down. When people smoke, eat, or otherwise consume marijuana or products containing marijuana-derived cannabinoids, the plant’s naturally occurring phytocannabinoids bind to the brain and body’s endocannabinoid receptors, because their molecular structure is nearly identical to the endocannabinoids naturally produced by the body.
Research into the endocannabinoid system is ongoing, but so far, scientists have identified two types of receptors. They are known as CB1 receptors and CB2 receptors, and the THC found in marijuana can bind to both.
CB1 receptors are found primarily in the brain. They’re concentrated most heavily in the hippocampus, basal ganglia, cerebral cortex, and amygdala, the parts of the brain associated with memory, reward, learning, pain, anxiety, and movement control. CB1 receptors can also be found throughout the body, but in lower concentrations.
Although CB2 receptors are also found in small concentrations in the brain, they’re generally thought of as peripheral receptors, meaning they are found in higher concentrations throughout the body, away from the brain. They’re primarily found in immune tissues, such as lymph nodes and the spleen, and the peripheral nervous system. Scientists now believe that CB2 receptors play an important role in immune responses such as inflammation.
Scientists have identified two naturally occurring endogenous cannabinoids (endocannabinoids). They are known as anandamide (AEA), a term derived from the Sanskrit word for “bliss,” and the less colorfully named 2-arachidonylglycerol (2-AG).
The Role of the Endocannabinoid System
Modern researchers believe the primary purpose of these receptors is to maintain homeostasis, or internal stability. For example, injuries and illnesses can cause pain, which throws off the body’s homeostasis. The endocannabinoid system releases chemicals to ease the pain and return the body to a state of ease.
Being careful with the amount of phytocannabinoids (like THC and CBD) in the endocannabinoid system at any given time is an important part of being a responsible cannabis consumer.
To offer an idea of how important it is, here are just a few of the biological processes thought to be linked to the endocannabinoid system:
- Motor control
- Sleep cycles
- Cardiovascular function
- Muscle and bone formation
- Reproductive system function
- Liver function
- Nerve function
The above list contains only some of the bodily functions linked to the endocannabinoid system. Research into this fascinating field is still in its infancy, so most marijuana researchers assume that additional endogenous cannabinoids and receptors will be discovered with time.
Key Differences Between Endocannabinoids and Phytocannabinoids
Endocannabinoids break down faster than phytocannabinoids like THC, which means they produce longer-lasting effects. Smoking or otherwise ingesting the cannabinoids found in marijuana also introduces more of them to the body at once. The effects of individual phytocannabinoids are also more complex, due to a phenomenon known as the entourage effect.
An Interesting Aside
Recently, scientific studies have suggested that the endocannabinoid system works a little differently from other systems of neurotransmission. While all neurotransmitters send chemical messages between neurons to regulate thoughts, emotions, and actions, they typically move in the same direction. In other words, the neurotransmitter leaves the presynaptic neuron and reaches a new, postsynaptic neuron, and that triggers a predetermined set of events. Cannabinoids work the other way around.
When a postsynaptic neuron in the endocannabinoid system is activated, the brain synthesizes cannabinoids on-demand using the fat cells already found in the neuron. They then travel backward to the presynaptic neuron to attach to the receptor.
Researchers believe that cannabinoids function like a dimmer switch for other neurotransmitters. Since they perform their actions on presynaptic neurons, they can control how much of other chemicals are released in the brain, which also alters how messages are processed by the neurons. The overall effect is to regulate the production of other neurotransmitters, keeping everything in balance.
THC and the Endocannabinoid System
THC can bind to both CB1 and CB2 receptors. This produces a wide range of physical and psychotropic effects. The number of bodily and mental functions associated with the endocannabinoid system, coupled with THC’s ability to bind to both types of receptors, helps to explain the wide variety of effects produced by smoking marijuana.
Not only do consumers respond to THC in different ways, but different strains of marijuana are known to produce varying effects. This is partly due to what is known as the entourage effect. Each strain of marijuana has different concentrations of not just cannabinoids, but also terpenes and other compounds and they all work together to produce a specific effect on the body or mind.
While THC is the only cannabinoid that has been definitively determined to produce intoxicating effects, the concentration of other cannabinoids influences how it interacts with CB1 receptors. Since these are the receptors that create mood-altering and perception-altering effects, strains of marijuana with higher concentrations of cannabinoids like CBD and THCV are typically considered less potent. Unfortunately, while THC and CBD have been receiving a lot of attention, the lesser-known cannabinoids aren’t as heavily studied.
CBD and the Endocannabinoid System
Some say CBD does not directly bind to either CB1 or CB2. Yet, the fact that it produces measurable effects on the body is one of the factors contributing to scientists’ ongoing discussions about other possible cannabinoid receptors in the brain.
Some researchers believe that there are more, unidentified, endocannabinoid receptors that can accept CBD, while others have noted that CBD may decrease the speed at which the body breaks down anandamide and other natural endocannabinoids. It may also bind to other, non-cannabinoid receptors in the brain, including 5hT, a serotonin receptor, and TRPV1, responsible for pain and inflammation control.
What is currently known is that CBD decreases the uptake of THC by CB1 receptors. As a result, high-CBD strains of marijuana are great for treating CBD-responsive health conditions, but they’re not great for recreational users who want to get high.
What About Terpenes?
Like lesser-known cannabinoids, terpenes have not been heavily studied yet. However, there is some evidence that they may play an important role in determining what effects a particular strain of marijuana might have on the body and mind. There are two main theories regarding why different terpenes seem to produce different effects: the pharmacological hypothesis and the psychological hypothesis.
From a pharmacological point of view, terpenes may impact mood, physiology, and even behavior due to empirically observable interactions with the nervous system and the endocrine system. The evidence for this hypothesis comes from studies of linalool and limonene, both found in varying concentrations in many strains of marijuana. Linalool has been shown to create a sedative effect through its complex interactions with the sympathetic and parasympathetic nervous systems, while limonene increases serotonin, dopamine, and norepinephrine activity to produce antidepressant effects.
From a psychological point of view, terpenes, which are highly aromatic compounds, produce different effects on mood depending on people’s state prior to smelling the scent. This helps to explain why people’s responses to the smell of marijuana are so different. It doesn’t negate the biochemical actions of terpenes in the brain, but it does hint toward the variety of possible responses from individuals.
Prolonged heavy use of marijuana can cause consumers to develop a tolerance to its effects. The reason some people develop a higher tolerance to THC and other cannabinoids is that constant exposure to them causes the brain to decrease how many receptor sites are available. When heavy users cut back on smoking, they find that the number of active endocannabinoid receptors in their brains quickly returns to normal.
Is Marijuana Addictive?
It’s important not to equate developing a tolerance for marijuana with addiction. Unlike most drugs, marijuana is not physically addictive. In fact, coffee drinkers are more likely to develop a physical dependence on their drug of choice than marijuana smokers. Some people do develop what’s known as a psychological addiction, meaning that they have a strong desire to smoke marijuana, but they will not experience serious withdrawal symptoms upon cutting back or quitting. That’s good news for medical and recreational users alike.
How Long Does it Take for Marijuana to Work?
It only takes a few minutes to feel the effects of marijuana after smoking. The effects peak after around 30 to 60 minutes, but they can linger for several hours. Edibles take much longer to kick in, as the THC must be absorbed through the digestive system and metabolized by the liver before it becomes available to the body. Edibles can take anywhere from 20 minutes to three hours to produce noticeable effects, which may persist for nine hours or more.
How Long Does It Stay in the Body?
The half-life of THC is around 19 hours, but the metabolites produced as it breaks down have a half-life of 50 hours. THC is also highly lipid-soluble, so it can remain stored in the body’s fat cells for some time. That’s why marijuana enthusiasts who must pass drug tests need to abstain from smoking for at least two to three weeks. Some experts recommend longer periods of abstinence of up to 35 days.
The Bottom Line
While the science of marijuana may be fascinating to certain consumers, all the information in the world about how it affects the body and mind doesn’t change how it makes people feel. Knowing that CBD can help to balance the effects of THC by altering how it binds to cannabinoid receptors can point consumers in the right direction, but the best way to find a strain of marijuana that produces desirable effects is to experiment. Online cannabis seed distributors often list typical effects in their strain profiles. Have a look at i49.net for a full catalogue complete with strain profiles. Look for a well-balanced strain, then start with small doses and increase them slowly to avoid potential pitfalls like paranoia and anxiety and remember that everyone responds to the various components of marijuana a little differently.