How Cannabis Affects Your Liver
Research on how cannabis affects the human liver is still quite limited, but from the studies that have been done, we know that the relationship between the two can be somewhat complicated and can vary depending on the liver condition involved.
For most healthy individuals, cannabis use shouldn’t cause liver complications and may even potentially play a protective role against developing alcoholic liver disease and nonalcoholic fatty liver disease.
For those with more severe liver conditions, however, or those who are taking other medications, care should be taken to ensure that you are helping and not hurting your liver.
Although medicine still has many questions on medical marijuana and the liver, here is what science can tell us.
How cannabis interacts with the liver
To understand the effects of cannabis on the liver, we have to start with an explanation of how the liver is affected by the endocannabinoid system (ECS). The ECS modulates many of the human body’s most crucial functions — like sleep, energy, memory, hunger, inflammation, and mood, to name just a few — and helps keep them in homeostasis or internal balance.
The endocannabinoid system can be activated by common cannabinoids found in the cannabis plant, like THC and CBD, but our body also naturally produces its own cannabinoids (endocannabinoids) — and they also activate the ECS.
Studies show that activation of certain endocannabinoid receptors may worsen cirrhosis, enhancing factors like fibrogenesis, fibrosis, ascites, and steatosis. Activating a different endocannabinoid receptor, however, seems to have the opposite effect, counteracting fibrosis, steatosis, collagen deposition, and inflammation — promoting a healthy liver.
Endocannabinoids have also been shown to impact cirrhosis of the liver. Some can even act against fibrogenesis, improving liver health. So researchers are looking to further explore endocannabinoids as a potential target for the treatment of liver disease.
The benefits of cannabis for liver health
Existing research on the endocannabinoid system shows that activating its receptors via endocannabinoids may have a big impact on the liver — either helping or harming its progress. So how does cannabis, a plant that activates these same receptors, impact the liver?
First of all, it’s important to note that research on medical marijuana and the liver is still in its early stages, and the effects of cannabis on the liver have mostly been studied in populations with liver disease of different kinds — not healthy livers. That said, one small study did look at the influence of chronic cannabis use on liver function in general.
In this study, researchers found no significant differences in liver function for those with higher levels of THC markers in their blood — but they did find slightly better liver function for those with higher THC-OH levels. This research was limited due to a small sample size but suggests that chronic medical marijuana use doesn’t negatively impact liver health for healthy individuals.
Other research looks at cannabis and liver health relative to specific conditions or symptoms. For example, one condition that the effects of cannabis have been investigated is alcoholic liver disease (ALD). ALD is caused by heavy, long term alcohol use, and cannabis just might serve a protective role for this disease.
One very broad study found that those with the highest levels of medical marijuana use had significantly lower levels of ALD at all stages of the disease. These heavy cannabis users saw a 45% reduction in steatosis, or alcoholic fatty liver disease, a 40% reduction in steatohepatitis, or alcoholic hepatitis, a 55% reduction in alcoholic cirrhosis and fibrosis and an impressive 75% reduction in hepatocellular carcinoma, or liver cancer.
Another study, which tied lower levels of ALD to CBD use, seems to suggest that cannabis use (or even just CBD) may actually be protective against the deadly long term effects of alcohol use.
But it’s not just alcohol-induced liver disease that cannabis may help. marijuana may also protect against non-alcoholic fatty liver disease. One study found that cannabis use was tied to lower levels of this condition, in addition to ALD. So medical marijuana may be protective for our livers in general, not just as a protection against drinking.
Cannabis may also play a protective role in other specific conditions.
One study found that cannabis can protect the livers of patients suffering from psychosis — lowering the risk of steatosis.
Animal models also show evidence that cannabis use can improve symptoms of hepatic encephalopathy, likely via the anti-inflammatory properties of cannabis. Unfortunately, there have been no human studies on this condition to confirm the results.
Risk factors for cannabis and the liver
For other liver related conditions, however, cannabis use may have more complicated interactions. Chronic hepatitis C virus, for example, may be worsened by cannabis use. Animal studies show cannabis can actually worsen liver fibrosis and steatosis in hepatitis C. Human studies show that marijuana use can lead to suppression of anti-viral immunity in hepatitis C patients. In addition, studies on hepatitis C patients found that steatosis risk was predicted by daily cannabis smoking.
On the other hand, other studies have reported positive effects for hepatitis C patients using cannabis. One 2018 study found cannabis using hepatitis C patients had lower levels of cirrhosis and lower total health costs than nonusers. Another study found hepatitis C patients who used cannabis were better at adhering to their antiviral treatment and thus had better virologic outcomes. So for patients with this condition, cannabis could be helpful or harmful.
Beyond studies on hepatitis C, other worries for cannabis and the liver come from a study on CBD and mice. In this study, a high dosage of CBD led to fatalities for some of the mice subjects. Researchers noted elevated liver enzymes and increased liver size in the mice who died and concluded they died from liver issues. Other researchers, however, have pointed out some methodological problematic issues in the study.
For one thing, the dose of CBD administered was extremely high — a dose 100 times higher than the maximum recommended dose for Epidiolex, the only FDA approved CBD-based medicine for humans. But more importantly, the CBD was extracted using hexane — a solvent with known neurotoxic properties. It’s unclear whether the hexane was a factor in the mice’s death.
Beyond this, the sample size was only six mice, which is too small to have much statistical significance. Researchers on the study reported that 75% of the mice died — which would mean 4.5 mice died. Since this is an impossibility, we might wonder what other errors were made in this study. More research is needed to confirm or discredit these findings.
Another important area of risk management related to cannabis and the liver is drug interactions. Cannabis can interact with the drug metabolizing enzymes in the liver, which, if taken with certain medications, can cause them to become more or less potent and efficacious. In addition, certain drugs may make cannabis more or less potent.
While there has been little study on these drug interactions, we can deduce from what we know about pharmacology that certain drugs are more likely to have these interactions. For example, fluoxetine, fluvoxamine, fluconazole, clarithromycin, verapamil, itraconazole, voriconazole, and ketoconazole are all more likely to increase the concentration of THC and CBD in the blood by inhibiting its elimination from the body. In the other direction, the drug rifampin has been reported to reduce THC levels in the blood by 20-40% and CBD levels by 50-60%.
In conclusion, cannabis use is growing in popularity, and that should be no surprise considering its wide range of health benefits. Still, while the research is still limited, there are some interesting studies showing both risks and benefits of cannabis use on the liver. For healthy individuals, cannabis should not have a significant impact on liver function — it may even serve a protective role against developing alcoholic liver disease and nonalcoholic fatty liver disease. Still, for those with hepatitis C, or those using certain medications, cannabis use can cause complications.
If you do have a liver condition, it is advisable to work with a cannabinoid specializing physician to ensure you are taking the best steps for your liver health.
Cannabis use shouldn’t cause liver complications and may even potentially play a protective role against developing alcoholic liver disease. Read more
Marijuana May Protect the Liver from Alcohol — But Experts Urge Caution
Share on Pinterest Researchers are actively exploring cannabinoids that could be used to prevent or treat liver disease. Getty Images
The negative health consequences of misusing alcohol are becoming clearer every day.
Regularly exceeding the recommended daily limits of one drink for women and two drinks for men is associated with an increased risk for high blood pressure, stroke, and numerous cancers, including liver cancer.
Recently, researchers sought to understand the effects of regular alcohol and cannabis use on the liver.
While it may not be a good idea to combine intoxicating drugs, recent research finds that using alcohol and cannabis regularly has an unexpected effect on your health.
A 2018 study looked at about 320,000 people with a history of both misusing alcohol and using cannabis to discover what effect, if any, using both drugs had on liver health. What they found out was surprising.
Dr. Terence Bukong of the University of Massachusetts Medical School and the INRS-Institut Armand-Frappier Research Centre told Healthline: “The primary aim of our study was to assess the impact of cannabis use and the development of alcoholic liver disease.”
“Given that no clinical studies had previously evaluated the impact of cannabis use and the development of progressive stages of alcoholic liver disease in humans, we thought that this was an important research area which needed urgent investigation,” he added.
Dr. Hardeep Singh, gastroenterologist at St. Joseph Hospital in Orange, California, told Healthline, “Alcohol increases fibrosis in the liver, it has a direct toxic effect to liver cells and causes them to become inflamed. This causes scarring to the liver — advanced scarring of the liver is cirrhosis.”
He emphasized that the effect was very individual, with some people harmed by much lower alcohol intake than others.
But Bukong and team found that regular users of alcohol and marijuana significantly reduced the risk of alcoholic liver disease (ALD), and the heaviest cannabis consumers benefited the most.
The anti-inflammatory effects of cannabis are well-documented. Previous research had already found that cannabinoid receptors in the liver are potential targets for new ways to treat liver disease.
Activating these receptors with cannabis reduces the inflammation that happens early in ALD, slowing the progression of the disease.
However, Bukong cautioned, “Our studies could not ascertain which cannabis strains were used. So we couldn’t determine the cannabinoid content of what each individual ingested. We also couldn’t ascertain the dosage or modes of use, although it’s most likely through smoking.”
Singh emphasized, “However, some of this scarring goes away as the healthy liver regenerates, so cirrhosis can improve if an individual simply stops drinking. But, some scarring will remain.”
“My research group is currently working to discover which cannabinoids or cannabinoid formulations will provide the best therapeutic benefits for specific liver diseases,” Bukong said.
These anti-inflammatory properties are already being used to relieve pain, colitis (inflammation of the colon), multiple sclerosis, and arthritis.
“Our findings revealed that cannabis users were less likely to develop alcoholic liver disease, and cannabis-dependent individuals were the least likely individuals to develop alcoholic liver disease,” said Bukong.
He’s confident that “specific formulations of cannabinoids might soon be used [to] prevent or treat liver disease. My research group is actively working on important cannabis formulations which we hope will be important drug leads for future testing in the prevention and treatment of liver disease from inflammatory, metabolic, and even viral causes.”
Dr. Singh cautioned that one liver disease, hepatitis, is made worse by cannabis.
“Patients with hepatitis C who used cannabis had way more liver scarring than those who didn’t and more progression of their liver disease. Something in the cannabis could actually be increasing fatty liver disease and fibrosis,” he said.
Singh theorizes that some people have sensitivity to cannabis that influences whether they can benefit from it or not. “You can’t just tell the public marijuana is good for your liver, because there may also be people whose liver is harmed by it.”
He said current treatment, in limited cases, consists of “a short course of a steroid drug called prednisolone, for about eight weeks, which can help combat the effects of alcohol on the liver.”
He added that in some people with fatty liver disease, drinking two to three cups of black coffee per day has helped reverse scarring in the liver, although it’s not known which ingredient in coffee is providing the benefit.
According to National Institute on Alcohol Abuse and Alcoholism (NIAAA), drinking is responsible for roughly 88,000 deaths per year.
Could cannabis help reduce alcohol dependency to prevent liver disease?
A 2017 study looked at a clinical population of people with depression and alcohol use disorder (AUD) to find that marijuana had no beneficial effect, and could have worsened their depression.
The study concluded that — at least in people with depression — marijuana isn’t an effective treatment.
More evidence that cannabis won’t help wean people with AUD off alcohol is demonstrated in research that found that people treated for AUD, who also used marijuana, relapsed sooner than people who didn’t use marijuana.
There is strong evidence that stimulating the natural cannabinoid receptors in the liver can slow or even prevent the development of cancerous liver tumors. The health benefits associated with marijuana and cannabis products in general has created a lot of buzz.
Singh insists that, right now, too little is known about what effects cannabis compounds have on health.
“There are many substances in cannabis and it could be that one is really bad for the liver while another is beneficial. The take-home point is that more research is needed because we need data on both sides, good and bad,” he said.
The fact remains that cannabis is illegal in many parts of the United States and the world. It’s also important to remember that cannabis, like almost all drugs, is not harmless.
However, in a nod to the growing evidence that cannabis has medical benefit, the Food and Drug Administration (FDA) announced it will hold a public hearing May 31 to gather more information on the science, manufacturing, and sale of cannabis compounds.
Recent research finds that marijuana use is associated with a reduced risk of alcohol-related liver damage — including liver cancer.
However, there’s scant evidence that people who drink excessively can use marijuana to overcome a disorder. Research actually shows that it can worsen depression in some people with an alcohol use disorder.
As evidence grows that cannabis and cannabis-derived products can treat or prevent a broad range of health issues, it’s important to remember that marijuana is still illegal in many parts of the world.
Cannabis is a drug, and like any other drugs, has the potential to cause harm if misused.
A recent study shows that certain components in cannabis may help reduce inflammation associated with alcohol use and serious liver health issues.