If you’ve been reading up on cannabis science, you’ve probably seen lots of references to how cannabis is a much healthier alternative to certain pharmaceutical options that can negatively impact your liver.
All kinds of medications can build up in your liver and cause health problems later on, even over-the-counter pills like aspirin. But few people discuss whether cannabis in any form may have an impact on our livers as well.
Cannabis consumers may be especially interested in how cannabis edibles may affect liver health. Are they OK to consume? Or, because the liver is key to digesting food, do marijuana edibles overwork the liver even more, making edibles a less-than-healthy choice for everyone?
When it comes to the science of cannabis and livers, we unfortunately have very little data to work with. Few studies have addressed liver-related issues and cannabis, and those that have were mostly rodent studies and not direct studies on humans. Still, these studies, while limited, provide valuable insight into the ways cannabis may affect your liver.
To get a better idea of cannabis and its impact on liver health, we spoke with HelloMD’s Chief Medical Officer Dr. Patricia Frye to learn more about how to approach liver health as a cannabis consumer.
When it comes to cannabis edibles, Dr. Frye points out the lack of studies on this specific question. She also notes that she isn’t “aware of any data that suggests that edibles are hepatotoxic,” or in other words, damaging to liver cells.
She also points to the lack of studies on how cannabis—in any form—affects healthy livers. Most of the studies on cannabis and liver health have been designed to look at how cannabis affects folks with liver conditions or health issues that may impact the liver.
So, while we have some data for those with liver issues, for folks with healthy livers, it’s especially challenging to say how cannabis may affect their liver health. There just haven’t been any studies that look at this issue in healthy people.
In some ways, no news is good news. With so many cannabis consumers, it seems likely that medical professionals would have noticed liver issues in folks who take marijuana by now. But it’s always possible that long-term effects have gone unnoticed or have been attributed to other causes. We need more research on human models to really answer the question.
While we don’t have much data on cannabis’s effect on healthy livers, we do have some data regarding livers that are already compromised by some type of issue.
And it does seem like there may be benefits to consuming cannabis for certain liver conditions, such as:
When it comes to the research we do have, Dr. Frye says that “CB2 activation and blocking CB1 receptors in the liver may be hepatoprotective—decreasing fibrosis, inflammation and promoting hepatocyte survival and regeneration.” This could mean that cannabinoids which activate the endocannabinoid receptor CB2 but block the CB1 receptor are actually helpful for liver health.
As Dr. Frye explains it, “Hepatic CB1 receptors upregulate hepatic fatty acid production and promote liver fibrosis.” On the other hand, “CB2 receptors can suppress fatty liver disease and protect the liver from damage caused by decreased oxygen delivery.”
With CB2 activation people see decreased:
Still, cannabis’s effect on the liver depends greatly on the exact liver condition someone has. For example, Dr. Frye points out that “in patients with hepatitis C, the antiviral effect may be of some benefit. But this does not apply to hepatitis B.” For other conditions, cannabis seems to offer the liver some protection from damage.
Also, among alcohol users, for example, individuals who also consume cannabis showed significantly lower odds of progressing through the stages the alcoholic liver disease and developing:
And the data suggests that cannabidiol (CBD) may offer even more protection from nonalcoholic fatty liver disease (NAFLD). According to Dr. Frye, one German study even showed 20% reduced prevalence of NAFLD in patients who took cannabis. These cannabis consumers also saw reduced rates of obesity and diabetes, which are commonly associated with NAFLD.
And a new study on cannabis and liver health demonstrated that cannabis can play yet another a protective role, helping protect the liver in patients suffering from psychosis.
The study looked specifically at liver health for patients suffering from psychosis and found cannabis consumption was associated with a lower risk of liver steatosis in psychosis. Scientists aren’t sure if this protective effect has to do with cannabis’s metabolic effects on weight gain or if marijuana’s positively affecting liver tissue directly, but cannabis certainly seems to be beneficial.
It’s clear that cannabis can be helpful for certain liver conditions, but it could it also be harmful? As it turns out, there’s some evidence that cannabis may pose risks for your liver as well.
When it comes to taking cannabis for your liver, Dr. Frye warns that “heavy use may exacerbate end-stage cirrhosis.” So if you have this condition, you may want to avoid consuming much cannabis.
Those with chronic hepatitis C may also want to be cautious, despite the beneficial antiviral effects cannabis may have.
A 2008 study showed that daily cannabis consumers had higher incidence of fatty liver associated with chronic hepatitis C. Still, Dr. Frye points out that it’s “not clear if there is cause and effect.” It’s impossible to tell from the study whether those patients were simply more symptomatic, and so consumed more cannabis to address their symptoms or if cannabis was actually causing the fatty liver disease.
There’s also some worry after a study in which high doses of CBD given to mice led to the death of some of the subjects involved. The researchers concluded the mice died from liver issues because they had elevated liver enzymes and increased liver size.
Still, other researchers have noted issues with this research. For one thing, the dose was incredibly high—more than most humans would ever ingest and 100 times higher than the maximum recommended dose for Epidiolex, the only FDA-approved CBD-based medicine.
The CBD administered to the mice was also extracted using hexane—a solvent with known neurotoxic properties. So it’s unclear whether the hexane could have been a factor in the mice death.
In addition, the test was on a very small sample size—only six mice. And the researchers reported that 75% of the subjects died. But as critics have pointed out, this would mean that four and a half mice would have died, a true impossibility. Errors like this should certainly lead people to question the truth of the rest of the data in this study.
Still, testing of Epidiolex also found elevated liver enzymes in human subjects, too. So, we shouldn’t simply ignore this data. But we should take it with a grain of salt and balance it against the data showing CBD can be helpful for the liver in other studies.
If you’re concerned about your own liver health with cannabis, it’s best to talk to a doctor familiar with cannabis who can help you to figure out whether the plant—and in what form—is right for your situation.
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