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. Continue reading “Marijuana medical benefits – large review finds very few”
I have alerts set up to tell me whenever something is published on the internet about any adverse events that occur with respect to vaccines. A lot of it is nonsense pushed by the anti-vaccine religion, without any merit. Some are legitimate published articles, generally refuting myths about adverse effects. But today, we get the merging of my favorite topics – marijuana treats vaccine adverse effects. Yes, you read that right.
We all know about the pseudoscience surrounding the vaccine adverse effects myth – it’s almost always based on a misreading of the vaccine package inserts, anecdotes, false claims, and almost anything but facts. Rarely, vaccines can cause a serious adverse effect, no medical procedure is perfectly safe – however, the potential benefits far outweigh the risks of the vaccination.
So let’s take a look at this new nonsensical claim about both vaccines and marijuana. Grab a bag of Doritos and enjoy. Continue reading “Marijuana treats vaccine adverse effects – more pseudoscience”
I’ve always been amused by marijuana advocates – they vastly overstate the benefits and understate the risks, sort of the opposite of the anti-vaccine religion. Current research on cannabis shows that there is little robust evidence supporting most of its claimed medical benefits – for example, it does not cure cancer, despite what you see on the internet. On the other hand, there has been only a small amount of research examining the risks of marijuana smoking. But a 2016 article in a major journal examined the effects of secondhand marijuana smoke, and the results should cause us to examine laws to regulate public smoking of marijuana in the same way we do cigarettes.
Here in California, we would be calling the local swat teams to round up all the cigarette smokers in a public space, if the air has even a hint of cigarette smoke. Ironically, no one seems to care about cannabis smoke wafting over us and our children. Maybe some of us just assume that secondhand marijuana smoke was inherently safer than secondhand cigarette smoke. What does the scientific evidence say? Continue reading “Secondhand marijuana smoke – it may be unhealthier than cigarettes”
The internet is filled with crackpot ideas. I know, that’s a shocker. In today’s crazy, we have this article, “Six pharmaceutical drugs that immediately destroy your health.” Setting aside the odd “pharmaceutical drugs,” let me counter that with “pharmaceuticals save lives.” Even more, vaccines save lives (since they attack two of my favorite vaccines).
I don’t genuflect at the altar of Big Pharma. I realize they are a big business that need to generate more and more profits, and they frequently make decisions that favor profits over ethics. But for good or bad, more often than not, pharmaceuticals and vaccines save lives. And there’s plenty of evidence of that.
But when some random rant on the internet tries to claim that important drugs (and the list of six are worthwhile drugs) are dangerous and destroy your health, it needs to be addressed.
So let me examine their claims. This should be interesting. Continue reading “Vaccines save lives – a response to some ridiculous claims about drugs”
I’ve written extensively about marijuana treatment for various diseases. For example, using it to prevent or treat cancer? No clinical evidence support its use. In fact, a large review of published science on medical marijuana showed little evidence of it having a clinical benefit except for just a few conditions, one of which was chronic pain.
Apparently, there is little scientific evidence to draw conclusions about the benefits and harms of marijuana treatment for patients with posttraumatic stress disorder (PTSD) and chronic pain, according to two studies published recently in the respected journal Annals of Internal Medicine.
Let’s take a look at these two articles and determine what they say about marijuana treatment of PTSD and chronic pain. Continue reading “Marijuana treatment of PTSD and chronic pain – probably does not work”
Subjectively, one the wilder claims one can find on social media is that marijuana cures 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 the cancer itself, just dealing with the effects of the treatment.
So what has real research said about “marijuana cures cancer?” Well, not to give away the conclusion, but not very much. Let’s take a look.
Continue reading “Marijuana cures cancer? Scientific research says probably not”
This is Part 5 of a series of six articles discussing various medical uses for cannabis or marijuana. In this article, I review and summarize some of the evidence that marijuana supporters have used to claim that smoking weed during pregnancy is safe. And I look at data from high quality reviews that shows it isn’t. So let’s assess the science regarding marijuana and pregnancy.
As I have written previously, consumption of and growing marijuana should be completely decriminalized. And the laws need to be rewritten, not in the haphazard way it is now, but with protection and respect of rights of people to consume or grow (for personal use) cannabis. The criminal prosecution of marijuana use and distribution is a ridiculous waste of public resources.
There are numerous health claims made about marijuana, including its use for cancer, neurological disorders, and other medical uses. There’s even a whole area of belief that claims smoking cannabis is perfectly safe during pregnancy. Let’s look at this. Continue reading “Part 5. Marijuana and pregnancy – assessing the science”
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.
Continue reading “Marijuana for ADHD – what’s the evidence?”
On Sunday evening (8 May 2016), John Oliver, the English comedian and political satirist, talked about science and how we should embrace it during his HBO show, Last Week Tonight. The upshot is that John Oliver promotes real science – and critical thinking about bad science. And states that vaccines don’t cause autism.
Oliver is one of the best satirists on TV. His attacks on stupidity in politics and culture are classics. He’s been doing his shtick for many years on American TV, being one of featured correspondents for the Daily Show with Jon Stewart. I always looked forward to his reports, though always funny, they were generally pointed and quite intelligent.
His recent segment on science on his HBO show was a classic. And let’s take a look at how John Oliver promotes real science – and why it’s kind of sad that a comedian has to hit it out of the park.
Continue reading “John Oliver promotes real science – a comedian gets it right”
Editor’s note: This article was originally published in December 2014. It has been revised and updated to include more comprehensive information, to improve readability, or to add current research.
The name of this blog, of course, is the Skeptical Raptor. I’m not sure how I invented that name, but I like raptors, either the fossil dinosaur version, or the living dinosaur versions, birds of prey. They both actually work as a metaphor of what I try to do–provide scientific and knowledgeable analyses of the scientific consensus or critiques of beliefs and pseudoscience. Usually one leads to another.
Of course, I don’t pretend to be very nice about my critiques, probably another reason why I chose to put “Raptor” in the blog’s name.
So, you know I’d get super annoyed by those who reject science, then misappropriate the word “skeptic” (or for those of you who prefer the Queen’s English, sceptic). A denier is not a skeptic – the former actually reject the rationality and open-mindedness of real skepticism (and science), but they pretend they are the real skeptics. Oh really? Continue reading “I call it as I see it–a denier is not a skeptic”