It has been nearly three decades since California legalized medical marijuana cannabis, and in the intervening years, as 24 states and counting have legalized recreational use, the humble little plant has undergone a major rebranding – and not just the above-referenced name switch (back) from a Spanish-sounding moniker to a more scientific (and marketable) tag.

The herb once demonized as a corrupting vice among jazz musicians, beatniks and other degenerates has been transformed into a bonafide superstar of the wellness industry, with a diversified portfolio of tinctures, tonics and topicals; strains, concentrates and edibles that promise all variety of body-and-mind-enhancing benefits.

Head to a dispensary and your (ahem) ganjier might recommend a sativa-dominant strain to boost your energy and creativity, or an indica hybrid if you’re looking to zone out and relax. Does weed make you anxious? Well, your budtender might say, try the anti-anxiety properties in cannabidiol, aka CBD.

Alas, as it turns out, those claims may all be bullshit. 

According to recent scientific research conducted in Canada and the United States, and profiled on an episode of the podcast Science Vs, much of the most commonly touted weed wisdom doesn’t hold up under the microscope of peer-reviewed scientific scrutiny.

Now, that’s not to say that cannabis has zero proven health benefits. According to the National Institutes of Health, an overview of the past 20 years of research found that there’s “conclusive or substantial evidence” that cannabis can treat chronic pain, nausea and symptoms of patient-reported multiple sclerosis spasticity (muscle spasms).

There’s also moderate evidence that it can improve sleep for people with obstructive sleep apnea and ease symptoms of fibromyalgia, chronic pain and multiple sclerosis. And there is limited evidence that it helps a variety of other conditions, including appetite loss associated with HIV/AIDS, symptoms of Tourette syndrome and post-traumatic stress.

But a pillar of the commercial cannabis sales pitch is the ability for consumers to customize their high by selecting just the right strain to deliver their desired effects, whether that’s an energizing head high, a zonked-out, full-body couch stupor or a soothing sleep aid.

Until recently, though, very little genetic sequencing had been done on the plant – in part because cannabis’s status as a Schedule 1 narcotic severely limits the kind of research that can be performed in the United States.

But Sean Myles, an associate professor in agricultural science at Dalhousie University in Canada, set out to do just that. He and his team of researchers got a variety of strains from multiple Canadian growers – some White Rhino, some Dr. Grinspoon, some King’s Kush – and sequenced the DNA to see whether two different supplies of an allegedly single strain would be a genetic match.

In theory they should, just as two Honeycrisp apples bought at different grocery stores will be genetic twins. Instead, Myles and his team found no such resemblance. 

“[W]ith a lot of the samples, he couldn’t find much in common between them,” podcast senior producer Meryl Horn said. “And a third of the time, the White Rhino or whatever was more similar to a completely different thing than it was to the other White Rhino in his data set.”

He got the same results in other strains he studied. [Download the study here.]

“So in cannabis, you go to the store and they say, ‘this is Bubba Kush,’” Myles said. “And that’s the biggest piece of bullshit I’ve ever heard in my life. Cause that name means absolutely nothing.”

Okay, but what about the revered twin uber-ancestors: sativa and indica? Even a casual connoiseur can tell you that sativa tends to be invigorating and uplifting while indica gives a relaxing body high that might make you sleepy.

Myles studied this, too, analyzing samples both chemically and genetically, and found that while there were some minor differences in surface characteristics, like smell, the two allegedly distinct strains were indistinguishable scientifically.

His initial study was done with samples obtained from the Netherlands, but he repeated the study using Canadian weed and got the same results. A group of American researchers later performed similar tests on strains from California, Washington and Colorado and got the same result.

Myles theorized that decades of intensive cross-breeding are likely to blame.

“We’ve been using this plant like crazy and moving it around the world like mad, and it’s been shuffling and we’ve been mixing the genomes together like crazy, and then it goes underground and nobody’s allowed to talk about it,” he said. “And the only people who are able to go and do all this breeding are, you know, dudes smoking a ton of weed and, you know, breeding a bunch of cannabis. Things were flying around everywhere.”

He’s arguably besmirching the revolutionary work of the Emerald Triangle’s brave, pioneering cultivars, there, but evidently the results have held up in multiple studies.

What about CBD, though? This non-psychoactive compound is marketed everywhere these days, in gummies, topicals, toothpaste, even butt moisturizers and infused sports bras. The chemical is frequently touted as an effective treatment for anxiety, among other things.

Amir Englund, a research fellow at King’s College London, set up a double blind clinical trial to study CBD’s effects on relieving paranoia. He gave subjects varying levels of THC (the main psychoactive compound in cannabis) and CBD and had them report on their feelings of anxiety and paranoia.

The results indicated that CBD has no impact whatsoever. 

“And I was like, no, that can’t be true,” Englund told the hosts. “It was really depressing. It was just really, really consistent that CBD did not have an effect on pretty much anything that we studied.”

Except coughing. For some reason, the testing subjects who received higher levels of CBD coughed more.

Anxiety levels, Englund and other researchers say, are largely determined by the amount of THC consumed. So if you tend to get paranoid on weed, try consuming a bit less next time.

We should note, here, that the National Institutes of Health has left that research door open a crack, saying there is “limited evidence” that CBD can help alleviate anxiety in people with social anxiety disorders, as assessed by a public speaking test. And of course, the placebo effect can be powerful.

The Drug Enforcement Administration is reportedly reviewing the classification of cannabis, which would make it easier for scientists to conduct more scientific testing to enhance our understanding of cannabis and its effects. 

In the meantime, you can click here for a link to the Science Vs episode discussed in this post, and here’s a transcript of the episode complete with footnotes to the various studies referenced.

Feel free to comment below with observations on how the science discussed above is flawed or corrupt or otherwise bogus.

And here’s wishing all LoCO readers an excellent 4/20.