That Alarming CBD Liver Damage Study Is Pure Trash

July 22, 2019

It’s 2019 and we still live in a world where one small study, on mice, with a highly questionable methodology, published in a marginal journal, with major flaws, leads to a clickbait media panic.

Recently, you may have seen a Forbes article headlined “Marijuana Study Finds CBD Can Cause Liver Damage” that reported on a study out of the University of Arkansas for Medical Sciences.

It’s scary stuff:

Shockingly, researchers discovered that the mice given higher doses of CBD showed signs of liver damage within 24 hours. To that end, 75 percent of these animals in the sub-acute phase had either died or were on the verge of death within a few days.

But this panic and misinformation is nothing new—back in 1974, a study conducted at Tulane University supposedly showed that “the active ingredient in marijuana [THC] impairs the brain circuitry,” leading the press to dutifully run articles claiming that pot causes brain damage without a trace of skepticism.

The 1974 study was deeply flawed. In Smoke Signals: A Social History of Marijuana, author Martin Lee called out this exceedingly small study of rhesus monkeys as “a textbook case of scientific fraud”:

Shackled in air-tight gas masks, Heath’s monkeys were [regularly] forced to inhale the equivalent of 63 high-potency marijuana cigarettes in five minutes. Lo and behold, the primates suffered brain damage from suffocation and carbon monoxide poisoning, but Heath attributed the results to marijuana toxicity.

Lucky for us—if not Forbes readers—Project CBD, a non-profit dedicated to boosting science-based understanding of cannabidiol (CBD), have just released a detailed rebuttal to the Forbes article.

The Rebuttal

Much has changed in the last forty-five years, but the National Institute on Drug Abuse (NIDA) still holds a monopoly on the sole supply of cannabis that can be used for federally-approved studies. And the research they approve remains laser-focused on finding harm—either that or trying to create a pathway to patenting synthetic THC as a prescription drug.

Regardless of your feelings on the CBD study, it is hard to argue with dead mice—even if you are an all-knowing marijuana expert.

Mike Adams, author of the Forbes, wrote another article in which he claims there’s no such thing as an expert in cannabis because not enough is known about the plant and its effects on human beings. That’s a highly questionable claim, and I suppose it explains why he didn’t quote anyone in his article who might have poured cold water on the study’s more alarming claims.

For example, Project CBD.

In their rebuttal of the Forbes article, Project CBD says:

The breathless reporting in Forbes focuses on a single, flawed, preclinical study and exaggerates it to the point of falsehood… A close examination of the Molecules study reveals a Pandora’s box of strange statements, problematic publishing, and unreasonable experimental design. On the first page, the abstract makes a claim that is fundamentally impossible, stating that, with chronic administration of CBD, ‘75% of mice gavaged with 615 mg/kg developed a moribund condition.’ But there were only 6 animals that received this dose! One doesn’t need an advanced degree in science or math to recognize that something is amiss. Seventy-five percent of six equals 4.5.

Dead mice aside (or rather, dead half-mice), the biggest problem with the study, according to Project CBD, is that just like in the 1974 rhesus monkey study, the dosage administered was astronomically high.

Scientists force-fed mice a single dose of CBD, ranging from the supposedly ‘low’ dosage of 246 mg/kg up to a mega-dose of 2460 mg/kg CBD… The maximum human dosage recommended for the CBD-isolate Epidiolex is 20 mg/kg, which is over 100x less than what the Little Rock researchers force fed their experimental mice.

The researchers explain away this mega-dosing by pointing to something called allometric scaling, which is basically a set of guidelines for estimating an equally potent dose of a substance for humans and other animals based on body weight and body-mass index.

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