More and more places in the world are moving towards the legalization of cannabis and the growing popularity of this plant is undeniable. Its benefits are more and more recognized, but this does not prevent debates and stigmatization from still occurring all over the world. Some will argue that cannabis is not good for your health, while others will put forward its numerous medicinal properties.
Canada legalized cannabis in 2018 and to date, while federal legalization in the United States has yet to occur, more and more U.S. states are passing laws opening the door to medical and/or recreational cannabis. Mexico has temporarily decriminalized weed in its territory until the Mexican government legislates on the matter. This wave of legalization certainly opens the door to interesting discussions across North America.
If the trend persists, cannabis will be legalized in more and more territories around the globe over the years and that's why it is very important to understand its effects on human health. Many scientific studies will be conducted in the coming years to help us get a clearer picture of the role and impact of cannabis on our health, as well as the potential it has, especially at a medical level.
If you're reading this article, you've probably already wondered whether cannabis is good or bad for your health. To demystify this question, it is first important to understand what exactly this plant is and how it produces its effects on the body. The different studies cited in this article presenting the negative and positive effects of cannabis will also certainly help you clarify the situation.
What is cannabis?
Cannabis is a plant originating from Asia that is now cultivated in more than 185 countries. It contains chemicals called cannabinoids, which produce effects on the brain and the human body through cellular receptors found in the human body's endocannabinoid system. The various cannabinoids are found in the trichomes, the tiny transparent hairs found on cannabis flowers and leaves.
THC (delta-9-tetrahydrocannabinol) is the first of the main cannabinoids found in cannabis. This psychoactive compound is responsible for most of the plant's known effects on the body and the brain (notably the famous "high").
CBD (cannabidiol) is the second main cannabinoid found in cannabis. Unlike THC, CBD does not produce a psychoactive effect and therefore does not cause the feeling of being "high". This cannabinoid is currently the subject of several studies regarding its numerous therapeutic capacities. It could even modulate the psychoactive effects of THC, especially when the cannabis strain has a CBD concentration equal to or higher than that of THC.
Dozens of other cannabinoids are also present in cannabis, such as CBG, THCV, CBC and CBN (1).
A growing amount of scientific research is also pointing to the wide range of effects that terpenes can have on the body. Terpenes are the strong aromatic molecules that give cannabis its wide range of scents and flavors (2).
How does cannabis produce its effects on the body?
Cannabis acts on the body through what is called the endocannabinoid system. This system, discovered by scientists in the early 1990's, serves to maintain the body's internal balance (3). When a person consumes cannabis, the cannabinoids contained in the plant come into contact with the endocannabinoid receptors present throughout the body to produce its various effects. The two main receptors, CB1 and CB2, have been detected in the central nervous system, digestive system, liver, pancreas, cardiovascular system, lungs, muscles and more.
Cannabinoids are not only found in cannabis: the human body also naturally produces cannabinoid substances (4). One could say that the body is made to receive cannabinoids since it produces some by itself! ;)
Health effects of cannabis
Now that you know in more detail how cannabis affects our bodies, the same question remains: is cannabis good or bad for our health?
It is very difficult to paint an exact picture of the issue but to help you make up your mind on the subject, the following lines will present the main arguments from both sides. First, we will present you the different studies that tend to show that cannabis is bad for your health, and then we will present the studies that support the positive and therapeutic effects that cannabis can have.
Possible negative effects of cannabis
Cannabis can of course have adverse effects on some of its users and is not a totally safe product (as is the case with almost everything in life).
The risks associated with it depend very much on the frequency of use and the characteristics of the user himself. They are more likely to affect users who ingest high doses on a daily basis (5), teenagers, pregnant women, and people who are particularly at risk for mental health problems (6).
Smoke inhalation
Although studies have struggled to establish a true cause-and-effect relationship between cannabis inhalation and lung damage (7), there is no doubt that the act of smoking itself poses some risk to the lungs. Of course, this risk is eliminated if you choose to consume the plant in other forms (edible products, oils, etc.).
A 2014 study found that short-term exposure to cannabis smoke is associated with an increased risk of bronchodilation (8) and chronic cough, but it has not been clearly associated with lung function impairment, lung disease, or asthma (9).
On the other hand, it must be said that certain actions taken by stoners can contribute to lung injuries, although these cases remain rare. Habits such as smoking in an uncleaned bong or performing "smoke tricks" by holding the smoke with one' s breath for as long as possible, just to name a few, can contribute to lung injuries among its adepts (10).
Memory
Memory problems associated with cannabis use occur mostly in cases of heavy cannabis intoxication and rarely have long-term consequences.
However, for chronic users, this side effect may persist even after intoxication (11). In fact, people who consume more than 3 times a week are considered to be at greater risk of developing persistent memory problems (12).
The risk of addiction
Cannabis users are not without risk of developing an addiction, this risk is particularly high among heavy users and adolescents (13).
Like tobacco and alcohol, cannabis is a substance that acts on the brain and its excessive use can, in some cases, make it difficult to stop (14). Specifically, according to the Diagnostic and Statistical Manual of Mental Disorders, approximately 9% of people who have used cannabis will become dependent (15).
Withdrawal symptoms may occur if a tolerant and addicted person suddenly stops using cannabis (16). These symptoms, which include anxiety, depressive symptoms, irritability, strange dreams and decreased appetite, usually last about a week, but in some cases can last up to a month after quitting (17).
Many users, even daily users, will have no real struggle to stop or cut down on their use, while others may feel unable to stop. People who use the plant to help them cope with their problems are the most likely to become addicted, but a host of other variables may also come into play.
Even so, unlike addiction to alcohol and other hard drugs which can lead to serious physical health consequences (even death in some cases), cannabis addiction has not been shown to cause serious physical illness. However, quitting cannabis can be as difficult as quitting alcohol and/or other drugs (18).
Is it true to say that cannabis use can lead to other drugs?
A study conducted by Ontario Public Health (19) states that there is no evidence of a causal link between cannabis use and other substance use. However, among adolescents and early adopters who use cannabis frequently, there is a greater likelihood of subsequent use of other drugs (20).
Reduced ability to perform certain tasks
Driving
Cannabis use significantly impairs key executive functions essential for driving, including cognition, attention, memory, decision-making, and psychomotor functioning. Not surprisingly, a 2017 study conducted by the National Academies of Sciences showed an increased risk of motor vehicle crashes when cannabis was consumed by the driver (21). However, these data are arguable, given that cannabis remains in the bloodstream for a long time and that drivers involved in collisions may often have more than one drug in their system (22).
Although the degree of impairment may vary depending on consumption patterns, the THC concentration of the consumed cannabis, tolerance, metabolism and many other factors, it is safest to avoid driving while using cannabis (23). Indeed, it can decrease attention, concentration, coordination and can slow down reaction time (24).
Other tasks requiring a high degree of specialization and attention
Some other tasks can also be dangerous to perform while high. For example, since cannabis impairs attention and concentration, it is best to avoid working in environments with equipment that poses a safety risk to others and/or yourself. Tasks requiring a high degree of concentration and cognitive skills should also be avoided to optimize performance.
On the other hand, it is interesting to note that some people, because of their high consumption, have a very high tolerance to cannabis and the plant may not significantly alter their functions (25).
Cannabis & Teenagers
The dangers of cannabis are certainly more pronounced for adolescents who use it. The human brain remains in an active developmental phase until the age of 21, and during this time it is far more vulnerable than a mature brain to the long-term harmful effects of exposure to THC, the main active ingredient in cannabis (26).
Among the problems observed among young users, especially those who use frequently and for long periods, are difficulties in learning, memory, concentration, literacy and numeracy. In the long-term, this can lead to major difficulties in school and a higher dropout rate (27).
A 2017 study published by the American Public Health Association also found that frequent and too early use of cannabis can have adverse effects on brain development. For example, alterations in white and gray brain matter as well as cortical thickness, decreased functional connectivity, IQ and cognitive functioning can occur which can, in some cases, result in greater behavioral impulsivity (28).
Finally, as mentioned, the earlier in life cannabis use begins, the higher the risk of developing an addiction (29).
cannabis & Pregnant women
As the social acceptance of cannabis grows in today's society, it is pertinent to look at the risks associated with cannabis use by pregnant women.
Various studies have shown that maternal cannabis use may result in decreased birth weight of the baby, which could in some cases present an increased risk of the need for neonatal intensive care unit or intensive care unit placement, compared with infants whose mothers did not use cannabis during pregnancy (30). Other studies suggest that a child whose mother used cannabis during pregnancy is at risk for behavioral problems during development (31).
Anemia, confusion and memory problems may occur in pregnant women using the plant, but more studies are needed to prove a definite link (32).
However, the link between cannabis use during pregnancy and problems in both babies and mothers remains unclear, as other substances such as alcohol or tobacco may be involved in the studies conducted. Further research is needed to clarify the consequences of cannabis use by pregnant women (33).
Cannabinoid Hyperemesis Syndrome (CHS)
A very small number of cannabis users may experience a rare syndrome called Cannabis Hyperemesis (for which there is little research or literature). These include stomachache and severe nausea. The only remedy in these rare cases is to stop using cannabis completely (34).
Cannabis & mental health
It is not impossible that regular cannabis use may lead to an increased risk of anxiety and depression, although studies have failed to establish a direct causal link. There are many other variables involved in mental health, such as family history and predisposition to mental health problems (35). As mentioned above, the risk is also higher for those who started using in their teenage years (36).
Cannabis may also increase the risk of developing psychosis, which in rare cases may even lead to schizophrenia (especially in people who have a personal and/or family history of these disorders or who are otherwise predisposed to them) (37).
In conclusion, much more research and study are needed to establish causal links between cannabis and the negative effects described above.
However, here are some tips to reduce these risks (38):
Choose a cannabis strain lower in THC and higher in CBD;
Choose a consumption method other than smoking (e.g., ingestion of cannabis);
Decrease the frequency and amount of cannabis used.
benefits of cannabis
There are also many benefits associated with the use of cannabis and the medical potential of this plant is simply exponential.
The various cannabinoids and terpenes present in the plant each have significant medicinal properties when they come into contact with the body's endocannabinoid system, including playing an important role in regulating functions such as sleep, mood, energy, and pain (39).
Cannabis is one of the least toxic drugs
Many are those who doubt the medicinal capacity of cannabis because they are concerned about the risk of drug use.
An analysis conducted by Drug Science compared the harmful effects of 20 different drugs in the United Kingdom. It concluded that cannabis was less harmful to society than several other legal drugs such as alcohol and tobacco, which have a much higher risk of serious health damage and sometimes even of death (40). The study showed that cannabis is one of the least toxic drugs. In particular, it has not been reported to date any case of death caused by its consumption (41).
Cannabis has important medicinal properties
Chronic pain
Chronic pain is one of the leading causes of disability worldwide, and studies in this area confirm that cannabis has great potential to provide relief to patients suffering from it.
This is nowadays the most common reason why people turn to medical cannabis. Products rich in THC and CBD can greatly help people suffering from these ailments (42) and many people are replacing their conventional pain medications (for example, opioids) with cannabis. The results of a study conducted in Michigan in 2016 showed a 64% decrease in opioid use with cannabis (43).
Insomnia, anxiety and depression
Other popular reasons for therapeutic cannabis use are of course insomnia, anxiety and even depression. The plant could also help relieve symptoms of post-traumatic stress (44).
However, some people may feel anxious when they use it. One of the reasons for this is that high doses of THC can create feelings of anxiety and panic in some people, while small doses can relieve these ailments (45).
Epilepsy
CBD has shown particular effectiveness in treating Dravet syndrome and Lennox-Gastaut syndrome (LGS), both of which are childhood epilepsy syndromes that are generally resistant to anticonvulsant medications. Numerous studies have shown that CBD can decrease the number of seizures and sometimes even stop them completely.
In fact, medication with CBD to treat these two rare types of epilepsy is the first cannabis-derived medicine to have received FDA (Food and Drug Administration) approval in the United States (46).
cancer symptoms
Cannabis has been the subject of many conclusive studies regarding its effectiveness in stimulating the appetite as well as treating nausea and vomiting that chemotherapy can often cause (47).
The FDA approved a THC-based medication called Marinol to treat the symptoms of nausea and vomiting suffered by chemotherapy patients (48).
Inflammation
The two main cannabinoids found in cannabis, THC and CBD, are both of great help in reducing inflammation, including for people with multiple sclerosis, rheumatoid arthritis and irritable bowel disease. With the reduction or suppression of inflammation comes pain relief (49).
Lastly, the cannabis plant contains hundreds of cannabinoids and terpenes, each with its unique medical properties. When they act together, a synergy called the "entourage effect" occurs. This is when the effects of the plant multiply and become more powerful (50).
The benefits of the plant described above are only a small part of the picture and, certainly, the medical discoveries related to cannabis are far from over. Many more studies will be conducted in the coming years to allow us to discover more about the medical potential of cannabis.
In conclusion: What is the verdict?
It is very difficult to establish exactly how dangerous cannabis is to human health, as the risks associated with it depend largely on variables such as the profile of the user, the manner and frequency with which the plant is consumed and even the strain of cannabis chosen (51). The prohibition that has reigned in North America in the last century, in addition to the fact that cannabis is still illegal in many parts of the world, certainly makes it more difficult to carry out in-depth studies on the subject.
The more studies and research on cannabis will see the day, the more we will learn about this plant with 1001 virtues which probably still reserves many surprises in the medical field.
Taking into account the difficulties in proving the causal link between cannabis use and its associated risks, in addition to its many medicinal properties, could we say that the good weighs more heavily in the balance than the bad?
It's up to you to conclude!
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