Cannabis Is (Slowly) Becoming Legal
Cannabis has recently become legal in Canada, it is legal in 9 US states and medical use is legal in almost all states. There are many other countries around the world that have legalized or decriminalized cannabis use, as you can see from the map below.
Legal — Illegal but decriminalized — Illegal but often unenforced — Illegal
Cannabis Legalization Does Not Mean It’s Harmless
The world consensus is moving in favor of legalization, but that does not mean it is healthy. Alcohol and tobacco are both legal, and both cause cancer (1). The governments are simply giving people the choice. Individuals have to inform themselves of the pros and cons. It is not becoming legal because it is a benign and harmless substance. Any drug, legal or illegal, has advantages and disadvantages.
There is also the route of administration to consider. The most common by far is smoking, which is what I will start with.
The 4 Dangers of Smoking Cannabis
1. Smoking Cannabis With Tobacco Causes Cancer
If you smoke cannabis with tobacco you will still incur all of the same health risks as smoking tobacco. There is no safe level of tobacco use. Furthermore, it is a known cause of many different cancers:
Smoking is currently responsible for a third of all cancer deaths in many Western countries. It has been estimated that every other smoker will be killed by tobacco. (2)
2. Smoking Cannabis Without Tobacco Causes Cancer
Marijuana smoke contains many of the same carcinogens found in tobacco smoke. Therefore, even if you are only smoking cannabis, you are still increasing your risk of cancer. A 2010 meta-analysis found:
increased risks of prostate and cervical cancers among non–tobacco smokers, as well as adult-onset glioma [brain & spine tumors] (3)
3. Joints Are MUCH Worse Than Cigarettes
Compared to tobacco smoke, cannabis smoke contains double the amount of carcinogenic polyaromatic hydrocarbons (4). In addition, cannabis joints are smoked without filters, are less densely packed, inhaled more deeply and for longer. These factors led to 5 times greater absorption of carbon monoxide than an equivalent tobacco cigarette. Despite similar concentrations of carbon monoxide in cannabis and tobacco smoke (5).
A 2008 New Zealand study found smoking marijuana increased lung cancer more than tobacco (6). Furthermore, in terms of lung cancer risk, one joint a day was equivalent to smoking 20 cigarettes a day. This finding is not isolated and consistent with other research (7, 8).
4. Smoking Cannabis Increases Stroke & Heart Disease
A 2016 review of the literature found:
Smoking marijuana has been shown to increase the risk of MI [myocardial infarctions/ heart attacks] onset by a factor of 4.8 for the 60 minutes after marijuana consumption, and to increase the annual risk of MI in the daily cannabis user from 1.5% to 3% per year (9)
So, your risk of a heart attack increases almost 5 fold, directly after having a joint. In addition, daily cannabis smoking increases your risk by 1-3% per year. Furthermore, an Australian study found cannabis use more than doubled the risk of stroke (10).
Smoking Cannabis vs. Eating or Vaping Cannabis
The dangers discussed above are mostly due to the effects of inhaling cannabis smoke. And, not the effects of the active ingredient THC or the other cannabinoids found in marijuana. Eating and vaping are far safer than smoking, but you are still ingesting a drug (THC). And, all drugs have pros and cons.
Eating cannabis is likely the safest route, as the long-term effects of vaping are still unknown (11). However, vaping is definitely a lot better than smoking, and the best evidence to date confirms this (12). One study found only trace amounts of 3 toxins in cannabis vapor, compared to 111 toxins in cannabis smoke (13). But, before you start baking your hash brownies, there are a number of dangers to consider.
The 5 Dangers of Eating/ Vaping Cannabis
1. 10% of Users Become Addicted
In 2000, the American Psychiatric Association reported that 4.3% of the American population had been dependent on marijuana, at some point in their lives (13). Since then, this figure would have increased due to increasing legalization and changing public attitudes.
In 1993, US admissions for marijuana addiction constituted 7% of total addiction patients. In 2010, this rose to 19% of total admissions (14). It fell in 2014 to 15%. However, this fall may be due to increasingly liberal attitudes towards marijuana use. Users may not be perceiving addiction as necessarily negative, and therefore are not seeking treatment.
The drug produces withdrawal symptoms after dependency, which last for 1-3 weeks. These include irritability, anger, depression, insomnia, cravings, and reduced appetite (15).
2. Cannabis Use Increases Mental Health Problems
You can see from the graph below, that cannabis use clearly increases the risk of mental health problems (16). Namely, psychosis which is:
A severe mental disorder in which thought and emotions are so impaired that contact is lost with external reality. (17)
Psychosis is not something to be taken lightly. Moderate cannabis users double their risk of the psychosis, heavy users quadruple their risk. This effect is due to the THC and other cannabinoids, as the risk is distinct to cannabis consumption and not smoking.
3. Cannabis Use Damages Your Brain
We all know that when you are high, you are not at your sharpest. But, some of these effects can persist, even after one abstains from the drugs for 3 weeks or longer. Studies have found long-term impairments in attention, concentration, verbal fluency and decision making (18).
4. THC Decreases Male Fertility
- THC reduces sperm motility (19).
- Cannabis use decreases sperm concentration (20).
- THC decreases sperm viability (21).
- THC consistently reduces testosterone in animals. In humans, the results are mixed (20).
- ‘THC interferes with the normal physiology and functioning of the male reproductive organs’ and may increase the risk of testicular tumors (20).
It is clear that THC and cannabis are no good for men’s reproductive health. This is important as there has been a 52% decline in sperm counts over the last 40 years.
5. Cannabis Use During Pregnancy Increases Child Cancers & Behavioural Problems
Pregnant women should not use cannabis. Cannabis use during pregnancy decreases babies’ birth weights and increases birth problems (22). Moreover, children exposed to cannabis in the womb have increased inattention and impulsivity; decreased cognitive functioning, memory and learning (23). Furthermore, cannabis use during pregnancy increases the risk of leukemia, brain cancer, and muscle & bone cancers in children (24). Generally speaking, if a compound is damaging to babies it damaging to adults. Babies are just more sensitive to toxins.
THC crosses the placental barrier and directly affects the fetus (25). In an experiment on monkeys, administration of THC caused multiple miscarriages and premature births which all resulted in death (26). Only 8 of the 15 babies survived. THC was also found in the milk of nursing mothers when administrated during lactation.
- Cannabis is legal in several countries, and will probably become legal in several more.
- Cannabis is a drug (THC is the active ingredient) and is not benign and harmless.
- Smoking cannabis causes cancer and increases the risk of stroke and heart disease.
- 1 cannabis joint is equivalent to smoking 20 cigarettes.
- Vaping cannabis is much safer than smoking.
- Eating cannabis is the safest way to consume it, but it still has risks (listed below)
- 10% of users become addicted to THC.
- THC increases your risk of psychosis 4 fold.
- Long-term cannabis use reduces cognitive functioning.
- THC reduces sperm concentration and motility.
- THC is not safe for pregnant women, as it increases the risk of child cancers and behavioral problems.
Disclaimer: This post and its author does not endorse the use of illegal drugs. This information is for educational purposes only.
13. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association; 2000. Text Revision, DSM-IV-TR.