Does CBD Elevate Liver Enzymes?
I am someone who doesn’t trust anything until I have researched it myself. In fact, before I would give my pets full spectrum hemp extract (CBD), I got my certificate in the biology and therapeutic uses of medical cannabis from the University of Vermont Larner College of Medicine. I also made it my mission to share as much research and information with pet parents about cannabis and other holistic methods of healing as possible.
One of the questions my team and I are asked often is whether CBD is safe and if it has any negative effects on pets. Because of a recent study, a stern warning from the FDA, and negative coverage in mainstream media outlets, the question has been posed: “Does CBD elevate liver enzymes to dangerous levels?” To find out the truth, I consulted the country’s top holistic veterinarians and did a little digging to find the most current research and medical opinion.
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NEW! Study Reports No Evidence of Liver Toxicity Associated With CBD
A New study on the “Observed Impact of Long-term Consumption of Oral Cannabidiol on Liver Function in Healthy Adults” has reported no evidence of liver toxicity associated with CBD. “Observational data gathered from 839 participants — ages 18–75 from across the U.S. and known to be taking hemp-derived CBD products orally for a minimum of 30 days — showed that CBD at the doses consumed in the study is not associated with clinical liver toxicity. Previous studies have suggested that prescribed cannabidiol (CBD) products may cause elevations in liver tests (LT).”
“This study compared the prevalence of elevated LT in an adult population self-administering CBD with the normal and general adult population prevalences. A total of 28,121 individuals were invited to participate in this study, 1475 enrolled, and 839 (female: 65.3%, male: 34.7%) completed the study. Full-spectrum hemp oil was used by 55.7%, CBD-isolate by 40.5%, and broad spectrum by 3.8%. The mean – SD daily dose of CBD was 50.3 + 40.7 mg. The prevalence of elevated ALT was 9.1%, aspartate aminotransferase (AST) 4.0%, alkaline phosphatase 1.9%, total bilirubin 1.7%, with 85.5% of the ALT elevations < 2 · the upper limit of normal (ULN) with only 0.3% having ALT levels > 3 · ULN. The prevalence of ALT and AST elevations (9.1% and 4.0%) were not significantly different from known adult general population prevalences (8.9% and 4.9%). There was no significant association between CBD dosage and LT values. Thirty-three individuals with elevated ALT levels had follow-up LT performed with 21 having normal LT, 8 having the same severity of ALT elevation, and 4 having an increase in severity, 1 of which ultimately became normal.”
The results of the study concluded “Self-medication of CBD does not appear to be associated with an increased prevalence of LT elevation and most of the LT elevations are likely due to the conditions/medications for which the individuals are taking CBD.”
What About The Study That Alleged CBD Was Unsafe for Dogs Because of Elevated Liver Enzymes?
The original study that alleged that CBD raised liver enzymes was published in a medical journal called Molecules, and was conducted by the University of Arkansas for Medical Sciences. Researchers looked at the effect of various dosage amounts on mice, using the recommended dosage amount for humans to scale. The study found that mice who received higher doses of CBD showed liver damage within 24 hours, with 75 percent on the brink of death in a matter of days. Scary stuff, right?
There is just one big problem with the study: it was conducted using Epidiolex, an FDA approved CBD isolate, and the dosage was astronomically high. Epidiolex is NOT a full spectrum hemp extract, which means that the entourage effect is not in place and the amounts given were purposefully misleading.
To conduct the experiment, scientists fed mice single doses of CBD ranging from “low” at 246 mg/kg up to a mega-dose of 2460 mg/kg CBD. To break it down, for every kilogram of body weight, they gave the mice about 2.5 grams of CBD. This dose is over ten times the normal dose – which is unreasonably high, and which caused the study to be skewed away from reasonable use from the start. The study’s abstract also presents math that is impossible. Since only 6 mice were studied, 75 percent of mice would have been 4.5, leaving only 1.5 mice to survive. Perhaps it is the animal lover in me, but I do hope that whichever mouse was able to survive in two halves is living a healthy life to this day, but something tells me that this figure is simply incorrect.
Why Would the Makers of Epidiolex Want Negative Results?
Epidiolex is made by a pharmaceutical company called GW Pharmaceuticals, who has taken great pains to corner the market on cannabis. In fact, they routinely lobby for stricter regulations that only they can meet, for example, they have pushed for legislation making it harder for medical cannabis companies to be marketed unless FDA approved. So, pushing researchers to find an issue with liver toxicity can only serve to benefit them by allowing them to be the only company able to provide a product that potentially will NOT elevate enzymes when used as directed. By raising consumer skepticism and fear of cannabis, they can effectively corner the market.
Do Vets Think CBD Is Safe For Dogs?
Dr. Gary Richter, a holistic veterinarian and owner and medical director of Holistic Veterinary Care in Oakland, CA, has been using medical cannabis to treat dogs and cats in his practice for years. After years of research, Dr. Richter has spoken publicly about this study and shares that your pet cannot overdose on CBD, and elevated liver enzymes were reported incorrectly.
including Tylenol, raise liver enzymes, and when given extremely high doses of these common medications (or small doses over long periods of time) liver damage can occur. However, research has not shown that life-long use of cannabis has an adverse effect on the liver. In fact, it has shown the opposite, because elevated liver enzymes cease as soon as cannabis leaves the system (unlike dangerous pharmaceuticals) and CBD can be tolerated in dogs at very high dosages without fatal side effects.
“You always have to look at the clinical picture. Looking at one study’s research regarding elevated liver enzymes and focusing on it is a fear-based approach to medicine. And, it’s inhibiting our ability to understand this plant as a whole.”- Dr. Zac Pilossoph
Is CBD Safe For Dogs?
Studies have shown that CBD is actually safer for dogs than many prescription medications, like phenobarbital. In a study conducted by Colorado State University, 10 mg/kg/day or 20mg/kg/day was administered to dogs for 6 days. CBD was tolerated in the study population. There was an elevation in serum ALP in 36 percent of patients, and all other blood parameters were normal – nothing more than a reaction to normal over the counter medications. Six of the 30 dogs had vomiting, and all had mild diarrhea. 11 of 30 dogs experienced erythema of pinna and 10 of 30 dogs experienced nasal and ocular discharge. These effects were significantly safer than many side effects of both over the counter and prescription medications.
Sitting outside a West Hollywood, Calif., café with Miles at her feet, Denise recalls how a friend suggested she try a glycerin tincture of marijuana that is sold as a pet medicine in dozens of licensed medical marijuana dispensaries throughout Los Angeles. Within an hour after she gave Miles the tincture, the dog’s appetite returned, and he was no longer vomiting. “It couldn’t have been a coincidence,” Denise said.
“The other great thing is that in the last couple of weeks, Miles has been going to the beach, he’s been running, he’s being himself,” she continued. “If Miles was on the tramadol, he’d be in bed, and he wouldn’t be enjoying anything or eating anything, and he’d probably be dead. I’m just really grateful we found this.”
Though initially hesitant about giving her pet an unapproved drug, Denise figured where’s the harm? Miles has terminal cancer and would die soon. Besides, people can’t overdose on marijuana, she reasoned. “I wasn’t that worried. I was actually pretty excited, because it has been used with human cancer patients for pain and nausea,” Denise said.
People need to understand that this isn’t about getting my dog high. It’s about improving his quality of life.”
Denise, a pet owner who turned to marijuana to help her dog, dying of cancer
|||States where medical marijuana is legal |||
Differences in state and federal marijuana laws aside, public attitudes about the drug are in flux. In April, the Pew Research Center reported that, for the first time in four decades, most Americans (52 percent) favor legalizing marijuana. In addition, 77 percent of those surveyed said marijuana has legitimate medical uses. Such sentiment is notable, given the Food and Drug Administration’s position that marijuana is neither safe nor efficacious for treating any human or animal disease.
If it’s good enough for me
|||After marijuana relieved Ernest Misko’s back pain, he started feeding the drug to his geriatric pet cat Borzo when the animal had difficulties walking. Within a few days, Borzo was walking normally again. (Photo by R. Scott Nolen )|||
“I don’t get high from (marijuana), but the pain goes away. So I tried it on my cat, my 24-year-old cat, who’s feeling better,” Misko said.
My position is the same as the (American Medical Association’s). We need to investigate marijuana further to determine whether the case reports I’m hearing are true or whether there’s a placebo effect at work.”
Dr. Douglas Kramer, an advocate for marijuana’s potential as a veterinary therapy
My gut reaction is they do probably provide some therapeutic effect benefit. But I’m never going to say there’s enough benefit that marijuana should be given to pets. I’m saying there’s enough justification that we need to study it.”
Dr. Dawn Boothe, Clinical Pharmacology Laboratory director, Auburn University College of Veterinary Medicine