People who use cannabis have a lower risk of developing alcohol-associated liver disease (ALD), according to new research.
The study of over 66,000 patients, which was published in the journal Liver International, found that people who use cannabis the most, including those living with cannabis use disorder, could have the highest level of protection against ALD. Even casual cannabis users showed significant protection, with a reduced risk of alcohol-related liver complications.
ALD results from excessive drinking and is one of the leading causes of poor liver health and mortality across the world. Symptoms range from loss of appetite and energy, digestive problems and lack of sleep, to the more severe, including jaundice, confusion and liver failure.
Current treatment for ALD centres on abstinence from alcohol and positive changes in diet, and in more acute cases, liver transplantation. ALD is the leading cause of liver-related illness and mortality in the UK, with a rising number of cases linked to increased alcohol misuse. Despite its growing burden, effective therapeutic options remain limited, underscoring the need to investigate novel treatment pathways to mitigate liver injury.
The research, led by scientists at Virginia Commonwealth University, analysed data from 66,228 patients diagnosed with alcohol use disorder between 2010 and 2022. Researchers separated participants into three groups: non-cannabis users, casual cannabis users, and those with cannabis use disorder (CUD). Building on previous research that suggests the hepatic endocannabinoid system (the part of the ECS that regulates liver function) could play a role in protecting the liver from the harmful effects of alcohol consumption, the team investigated whether cannabis use might offer protection against ALD.
The study used a ‘propensity‐matched’ method to match participants from the three different groups. They were matched on attributes such as age, sex, weight, diabetes status, and other relevant factors.
Researchers found that those in the CUD cohort had a roughly 40% lower risk of having ALD, a 17% lower risk of hepatic decompensation (when the liver becomes so badly damaged that it is no longer able to repair itself), and a 14% lower likelihood of dying from any cause compared to participants in the other cohorts.
“The risk reduction was observed across the ALD stages with a gradient of effect between [cannabis use] and CUD. This pattern may suggest a dose–response relationship, though its interpretation remains uncertain, as it relies on diagnostic codes with no direct measures of cannabis consumption,” the study authors wrote.
The casual cannabis user cohort showed a more modest but still meaningful reduction in liver disease risk. These patients had a 19% lower risk of developing composite alcohol-associated liver disease.
Notably, casual cannabis users did not show the broader protective effects seen in the CUD group. Their risks of hepatic decompensation were similar to non-cannabis users.
This pattern suggests a dose-response relationship, where heavier cannabis use (as represented by CUD) provides greater liver protection than casual use. The researchers noted this gradient effect supports the hypothesis that cannabinoids, particularly CBD, may offer therapeutic benefits in a dose-dependent manner.
The researchers emphasise that their study does not prove that cannabis directly protects the liver from alcohol damage. Instead, it reveals a strong association that warrants further investigation. The findings could point towards new therapeutic approaches, particularly involving CBD. Previous research has suggested that CBD may have liver-protective properties, potentially reducing inflammation and preventing the progression of liver disease through various biological mechanisms.
However, the study also carries important limitations. The researchers could not measure actual cannabis consumption levels, relying instead on medical diagnoses. They also note that cannabis use itself carries health risks, including potential psychiatric disorders and cognitive impairment.
“In this large, multi-institutional cohort, cannabis use was associated with a reduced risk of ALD, consistent with prior observations,” the study said.
“Based on preclinical evidence, the observed protective effect is possibly attributable to CBD. Given the expanding body of experimental data supporting the hepatoprotective properties of CBD and its favourable safety profile, further studies evaluating its impact in ALD, using appropriate dosing and treatment duration, are both justified and warranted.”
