What’s in Your Weed?
What you don’t know might hurt you
Editor’s note: Some of you may have seen this story appear on the Scienceline site a few days ago and then disappear. It was removed to make sure it was fully copy edited as per our usual editing stream to double check for grammatical errors. If you have any questions about our editing policies, please email firstname.lastname@example.org.
When Valerie Curran asked college students to put her in touch with their doobie-smoking friends, she was being serious.
Curran is neither a drug dealer nor abuser, but she does tote a license to carry marijuana. She is a scientist at University College London, where she’s studying the impact of drugs on memory. Her most recent research explored marijuana use in a naturalistic setting: college-aged kids, in their own homes, smoking from their own stashes.
That may sound controversial, but Curran has a pragmatic outlook on illegal drug use: “Cannabis is the world’s most popular illegal substance,” she said. “If people are going to use it, they should be safe and we should know the possible impacts.”
In fact, as the scientific studies about marijuana accumulate, it’s getting harder to understand why the substance remains illicit, said Paul Armentano, deputy director of the National Organization for the Reform of Marijuana Laws in Washington, D.C.
Curran’s study, published in the British Journal of Psychiatry in October, tested each of its 134 participants on two separate days—once when they were sober and once when they were stoned. On both days, she read them a short passage and tested their memory of its content immediately after hearing it, and again 30 to 40 minutes later. Then she took a sample of their marijuana to test in the lab later.
It turned out the kids smoking weed containing lots of the chemical cannabidiol (CBD) could remember details of the story just as well stoned as sober. Meanwhile, those smoking the low-CBD marijuana fit the stereotype of the forgetful pothead.
The findings fit into a growing library of data demonstrating the possible health benefits of CBD, which is naturally found in marijuana. CBD appears to fend off cancerous tumors, prevent diabetes and epileptic seizures, and protect nerve cells from degradation. It doesn’t combat the effects of THC, the ingredient in marijuana that causes a “high,” and can even prevent anxiety. On top of all that, Curran’s preliminary research suggests that CBD can help prevent marijuana users from becoming addicted to the substance.
“CBD has a vast array of potential therapeutic properties,” said Armentano. “We don’t have conventional medicine on the market right now that can yield these responses.”
But what worries Curran is that recreational users in Europe and America smoke marijuana that’s increasingly low in CBD, at the expense of their health and possibly their own smoking preference; seventy-five percent of the study’s participants smoked strains with high THC and low CBD, but only 34% said it was their favorite type of weed. “Experienced users probably prefer high CBD, but they can’t get it,” said Curran, pointing out CBD’s anti-anxiety properties.
Leslie King, a forensic scientist and consultant for the United Kingdom’s Department of Health, speculates that this pattern is supply-driven: the threat of fines and jail-time for marijuana possession drives dealers to grow their product instead of import it. And as they breed the plants with the sole aim of increasing THC levels, CBD falls by the wayside simply due to chance, he surmises.
Strains with high THC and high CBD do exist, but recreational users have no way of knowing the CBD content of their weed—you can’t see it, smell it, or taste it.
In California, where medical marijuana is legal, analytics labs like Steep Hill and Rm3 test patients’ marijuana samples for their THC and CBD content, but only for medical purposes, and only in California.
ProjectCBD, a group that promotes research on the medical utility of CBD, and the San Francisco Patient and Resource Center, a medical marijuana supplier, provide the THC and CBD levels of several strains of cannabis on their websites. This information has limited applicability, however, since what passes for “Purple Diesel” in Los Angeles isn’t necessarily the same weed as “Purple Diesel” in San Francisco, let alone New York.
Although standardization cannot be achieved on the black market, it could be if marijuana were legalized, said Tom Angell, spokesman for Yes on Prop 19, an organization advocating the legalization and taxation of marijuana in California. As evidence he cites the labs testing for potency, mold, contaminants, and CBD content that sprang up once California legalized medical marijuana.
Armentano has no doubt that standardization and labeling would become regular practice if recreational marijuana were legalized.
“What if every time you bought a can of beer you had no idea how drunk it was going to get you?” he asked. “I think all consumers want to know what’s in the products they’re using.” Proper labeling is essential to protect consumers and allow them to make informed choices, he added.
“We definitely can’t have that right now, under Prohibition,” Angell points out. “We leave all that up to the gangs and the drug cartels.”
Even if legalization and standardization for recreational use would make marijuana safer, Angell and Armentano agree that it’s not likely to happen anytime soon. Organizations like Nip It In The Bud and the League Against Intoxicants are opposed to marijuana legalization under any circumstances, and the federal government still classifies marijuana as a Schedule I Controlled Substance, meaning it’s considered to have no potential medical use.
When asked to comment on whether legalization could potentially lead to standardization for optimal health and safety, a public affairs officer for the U.S. Drug Enforcement Administration simply reiterated that “scientific studies have never established that marijuana can be used safely and effectively for the treatment of any disease or condition.”
Others disagree about what the science says. “We know it has medical benefits,” said Peter Clark, a bioethicist at Saint Joseph’s University in Philadelphia. “The issue now is legal and political.”
And despite indications that CBD has a slew of potential health benefits on its own, doesn’t impact mood, doesn’t cause intoxication, and has a lower risk of overdose than ibuprofen, only a handful of researchers in the United States can acquire permission to work with the substance. This is simply because of its association with the marijuana plant, said Armentano. He hopes policies and attitudes will change as we continue learning about marijuana and CBD from studies like Curran’s, which are carried out in other countries.
“Unfortunately,” he added, “in the United States especially, I don’t think science drives public policy.”