A major concern about cannabidiol (CBD) involves liver safety. And a study on this topic carried out by researchers at the University of Arkansas for Medical Sciences has had rippling effects across the CBD community, leading many to wonder if CBD is as safe as they thought.
Here, we break down the science of these results:
In this study, 8-week-old male mice (considered to be the equivalent age of adult humans) were given different dosages of a concentrated CBD-enriched extract.[1] Acute toxicity (24h) as well as sub-acute toxicity (10 days) was investigated. CBD doses were chosen to provide estimated equivalency to human doses.
The highest dose (2,460 mg/kg) showed clear evidence of acute liver toxicity. Lower doses did not show similar results administered acutely; however, given over a 10-day duration, lower doses also showed signs of liver toxicity.
The researchers concluded that “despite the beneficial effects of CBD in the treatment of certain therapy-resistant seizures, it poses a risk for liver injury. Furthermore, the probability of CBD-drug interactions appears quite high.”[1]
The results of this mouse study has raised a lot of eyebrows so we have outlined its limitations here:
The dose in the study was unrealistic.
The first point of contention is the dose of CBD that was used in this study. The maximum dose equivalent is way above what is normally consumed by most CBD users. The authors even noted that the dose of “200 mg/kg CBD is not applicable to most real-life scenarios.”[1]
Many drugs taken in excessive amounts could cause liver damage.
Paracetamol, which is a common over-the-counter drug, is known to cause liver damage when taken in high doses acutely or over a prolonged duration of time.[2] And this is true for many, many products.
Epidiolex®, prescription CBD for epilepsy, can also cause abnormal liver values and there is indeed a warning on the medication label concerning elevated liver values. However, since this is prescribed for severe epilepsy (thus requiring a high dosage), a doctor must recommend the medication to a patient and monitor their liver values before and during treatment.
One study alone should not cause panic.
The results from this study should instead serve to inform the public that toxicity at high doses should be a concern as with other medications. Caution should also be exercised when taking CBD together with other medication, as it can cause interactions.
We always recommend speaking to your doctor before starting CBD or medical cannabis and always, always remember the tips on how to buy quality CBD.
Image Credit: Steve Buissinne
Image Source: https://pixabay.com/photos/capsule-pill-health-medicine-1079838/
References
- Ewing LE et al. (2019): Hepatotoxicity of a cannabidiol-rich cannabis extract in the mouse model. 2019;24(9):1694.
- Tanne J. Paracetamol causes most liver failure in UK and US. BMJ. 2016;332(7542):628.