Skip to content
Home » cannabinoids

cannabinoids

marijuana cure cancer

Does marijuana cure cancer? Robust scientific evidence is lacking

Subjectively, one of the wilder claims one can find on social media is that marijuana can cure cancer. Or cannabis prevents cancer. It doesn’t matter what form – smoked, eaten, hemp oil (which is manufactured from the seeds of cannabis plants that don’t contain much THC, or tetrahydrocannabinol, the active hallucinogenic agent of cannabis) – some advocates for cannabis will try to make the argument that it is some miracle drug for cancer.

But is it? Yes, there are systematic reviews that indicate that cannabis may be effective in reducing nausea and vomiting in chemotherapy. But research has generated negative results in some well-done clinical trials and some positive results in others. But that has nothing to do with actually curing or preventing cancer itself, just dealing with the effects of the treatment.

Furthermore, a 2022 systematic review (again, the pinnacle of the hierarchy of biomedical research) showed that “evidence from RCTs (randomized clinical trials) that medicinal cannabis increases appetite in people with cancer is limited.

However, this article isn’t about appetite or nausea related to cancer, it’s about whether cannabis can cure or treat cancer.

So what has real clinical and scientific research said about whether marijuana can cure cancer? Well, not to give away the conclusion, but not very much. Let’s take a look.

Read More »Does marijuana cure cancer? Robust scientific evidence is lacking
cannabis sleep

Cannabis might be detrimental to sleep — new study

It’s clear that medical claims about cannabis, like improved sleep, are often used as a strawman for the attempts to get marijuana legalized. However, contrary to the popular belief about cannabis contributing to good sleep, it might actually be detrimental according to a new peer-reviewed study.

There are many of us that think that legal restrictions against marijuana was outright ridiculous, especially when other drugs, like cigarettes and alcohol, are completely legal. But where we draw the line is trying to push a narrative that cannabis has many medical benefits — most were overexaggerated or non-existent.

Marijuana cannot treat any of the 200 or more cancers. It cannot treat nonexistent vaccine injuries. Marijuana cannot treat most neurological conditions. I could go on and on, but scientific studies of most claims about cannabis as a treatment for anything have ended up with nothing.

So let’s take a look at the claims about cannabis and sleep.

Read More »Cannabis might be detrimental to sleep — new study
Marijuana medical benefits

Marijuana medical benefits – large review finds very few

Most states in the USA, and many countries across the world have passed legislation that allows the use of marijuana for medical purposes. Some of this legislation is dependent on various claims, many of which appear to be based on weak or nonexistent scientific evidence. Of all of the purported marijuana medical benefits, only a handful are supported by real evidence.

This review, Committee on the Health Effects of Marijuana: An Evidence Review and Research Agenda (pdf, which can be downloaded for free by registering or can be found online here), published by the influential and prestigious National Academies of Science, Engineering, and Medicine, examined more than ten thousand scientific studies that involved cannabis and various medical conditions. The value of such a review is that it examines not only the quantity of evidence supporting a claim but also the quality of such evidence. In the end, it gives much more weight to high-quality evidence.

I know many comments will drop on this article that “you haven’t read that incredible study published in Journal of Weed and Cancer Cures” – that misses the point. The National Academies is a highly respected institution, made up of the most respected scientists in the USA. And the committee that created this review is made up of leading public health, cancer, epidemiology, pharmacology, and psychiatry, all fields germane to understanding clinical and basic scientific research into cannabis.

Moreover, a review like this does two things – it gives more weight to well done clinical trials and pre-clinical studies, and it eliminates poorly done and biased studies. This is how science works – examine ALL of the evidence before coming to a conclusion. Pseudoscience, on the other hand, is to have a conclusion, like “weed cures cancer,” and only seeking evidence that supports that preordained conclusion.

Furthermore, and this cannot be stressed enough, this review is not opinion. It is not belief. It is not cherry picking. It is a critical analysis based on thousands of studies published in peer-reviewed journals. This is not published in a pro-cannabis website that cherry picks, misinterprets, and overrates a one-off study in an obscure journal. The report is over 400 pages long – most of you will not read even a few pages, because it is a dense scientific review written by some of the top scientists in the USA. Before you denigrate the study, I would suggest you read it carefully.

To save you time from reading the 400+ page opus, which I did, I divided up the medical evidence from strong to none of the evidence in support of benefits and of risks from smoking cannabis. Not to bury the lede, but there are only three conditions for which there is strong, overwhelming evidence benefits of marijuana. Just three.Read More »Marijuana medical benefits – large review finds very few

Marijuana for ADHD

Marijuana for ADHD – what’s the evidence?

Those of you who follow this website know that I frequently take down myths about the medical usefulness of marijuana. Let’s just say the evidence barely reaches the level of “sparse.” Recently, Tara Haelle pointed me to an article that trumpeted using marijuana for ADHD, attention deficit hyperactivity disorder.

ADHD is a psychological disorder in which the individual is unable to focus, is overactive, is unable to control behavior, or a combination of these, not appropriate for the age of the individual. Diagnosing ADHD is often difficult, because the differential diagnosis for the condition can be confused with or related to other emotional, psychiatric or neurodevelopmental disorders such as anxiety, major depressive disorder, and bipolar disorder.

There are some treatments available for ADHD, including stimulants such as the well-known medications, methylphenidate, or better known by its trademarked name, Ritalin, and Adderall, a mixture of two amphetamines. These stimulants are very effective for treating ADHD, but there are some risks to its use, and the effectiveness appears to lower over time.

So let’s look at marijuana for ADHD – it’s pretty weak, but let’s give it a good scientific skeptical analysis.

Read More »Marijuana for ADHD – what’s the evidence?

Part 6. Medical uses for cannabis – the TL;DR version

This is Part 6  of a series of six articles discussing various medical uses for cannabis or marijuana. In this part, I summarize all of the five previous articles into some bullet points so that you have quick and fast access to some scientific information about medical uses for cannabis or marijuana.

In case you missed them, here are the first five articles in this series:

Part 1. Marijuana and medicine assessing the science.

Part 2. Marijuana and cancer – assessing the science

Part 3. Marijuana and neurological disorders – assessing the science

Part 4. Marijuana and health risks – assessing the science

Part 5. Marijuana and pregnancy – assessing the science

Maybe you don’t agree with the science about marijuana’s role in medicine. But that’s not how science works. The evidence should lead you to a conclusion (actually, the acceptance or rejection of a hypothesis). One shouldn’t form an a prior conclusion, then go hunt for data. That’s not how it works.

As new systematic or meta reviews bring more clinical evidence of the benefits of the medical uses for cannabis – this takes time – maybe evidence based medicine can incorporate marijuana into the armamentarium of medical practice. But only real clinical evidence matters.

So let’s review where the evidence leads us.Read More »Part 6. Medical uses for cannabis – the TL;DR version

Part 1. Marijuana and medicine assessing the science

I suspect, like legal same sex marriage, social norms are changing across the USA (and the world), which has lead to the decriminalization of marijuana in 23 states and the District of Columbia for some medical conditions. The US Federal Government, has shown little enthusiasm in enforcing Federal law about cannabis, although the Federal government retains the highest authority in regulating certain drugs like marijuana. So let’s look at marijuana and medicine assessing the science critically.

It’s clear that rational people still want regulations for marijuana, including prohibitions against public smoking (I don’t want second hand cannabis smoke wafting over me or my children, as much as I don’t want to inhale other people’s tobacco smoke). And a safe society would have strict regulations that would forbid marijuana smoking by individuals who have roles in public health and safety like physicians, pilots, mass transit drivers, and others.

But I think those would be reasonable boundaries for legalization of cannabis that would be reasonable to most people. But this is not the point of this article.

As the push to legalize marijuana for personal or medical use gains traction in the USA, there has developed a strong belief, unsupported by evidence, of the value of the medical uses of cannabis. What is troublesome is that the pro-marijuana side seems to make claims about the medical uses of cannabis that appear to be only tenuously supported by real scientific evidence.

In fact, some of the claims are downright dangerous. The reasons for pushing this is probably, though I can only speculate, to make it appear that marijuana is some miracle product, so let’s speed up the legalization of it. It’s like the Food Babe telling us that kale is the miracle food, except that kale isn’t illegal. It does taste awful (but again, not the point).

Because of the amount of scientific information, this article is part 1 of a 5-part series about marijuana and medicine – assessing the science. For detailed analysis of various aspects of the science of marijuana and medicine, check out each of the subtopics:

Part 2 – Marijuana and cancer
Part 3 – Marijuana and neurological disorders
Part 4 – Marijuana health risks
Part 5 – Summary of marijuana and medicine

Read More »Part 1. Marijuana and medicine assessing the science

Part 2. Marijuana and cancer – assessing the science

This is Part 2 of a series of six articles discussing marijuana’s use in medicine and health care. In this part, we discuss marijuana and cancer – probably one of the most passionate and controversial “debates” associated with the use of cannabis.

It’s clear that there are numerous claims about the value of marijuana in preventing or treating various cancers. But what are facts? And what is smoke?

In this article, I’ll look at some of the more prominent claims, along with a skeptical analysis of those claims.

Read More »Part 2. Marijuana and cancer – assessing the science

Part 3. Marijuana and neurological disorders – assessing the science

This is Part 3  of a series of six articles discussing marijuana’s use in medicine and health care. In this part, we discuss marijuana and neurological disorders – probably the only field of study regarding medical uses of cannabis that has a robust area of clinical research.

Although research into the use of marijuana and cancer takes all the news these days, there is probably just as vigorous research into neurological disorders.  If you read the story regarding CNN’s chief medical correspondent, Dr. Sanjay Gupta, who claimed he changed his mind about marijuana, you’d know he was also convinced that marijuana had some great potential in mental health. But is there really any high quality evidence?

In this article, I’ll look at some of the more prominent claims, along with a skeptical analysis of those claims.Read More »Part 3. Marijuana and neurological disorders – assessing the science

Part 4. Marijuana and health risks – assessing the science

This is Part 4  of a series of six articles discussing marijuana’s use in medicine and health care. In this part, we discuss marijuana and health risks – even if there is evidence that marijuana had medical benefits, there must be a review of the risks of using it.

Only in junk medicine (see homeopathy or chiropractic, for example) is there a promise of great results with no risks. In real medicine, all benefits are balanced against the real risks of any medication or procedure.

The whole foundation of evidence (or science) based medicine is science – “it is the only set of methods for investigating and understanding the natural world.” Thus, the best factual evidence includes clinical research that describes not only the effectiveness, but also the risks, of a particular medical procedure.

In this article, I’ll look at marijuana and health risks – along with a skeptical analysis of those claims.Read More »Part 4. Marijuana and health risks – assessing the science

Marijuana and cancer – what are facts and what’s just smoke

Editor’s note–this article has been updated and included into a multi-part series on marijuana and medicine. Check it out there. 

If you spend any amount of time on Twitter, Facebook, or just researching cancer treatments on the internet, you will run across something about marijuana and cancer – someone will claim that smoking pot, eating pot, hemp oil (which is manufactured from the seeds of cannabis plants that don’t contain much THC, or tetrahydrocannabinol, the active hallucinogenic agent of cannabis), or some other consumption of cannabis will cure or prevent cancer.

Of one hand, studies of cannabis’ effectiveness in reducing nausea and vomiting in chemotherapy, one of the the most common claims,  has generated negative results in some well done clinical trials and some positive results in others. But that has nothing to do with actually curing or preventing the cancer itself, just dealing with the effects of the treatment.Read More »Marijuana and cancer – what are facts and what’s just smoke