Marijuana Use Was Associated With Less Liver Fat in a 2023 U.S. Study, but Not Less Liver Scarring
A 2023 cross-sectional study found that adults who reported using marijuana within the previous 30 days had lower odds of liver steatosis—an accumulation of fat in the liver—than people who had never used it. The finding does not show that marijuana prevents or treats fatty liver disease, however. It describes an association, and the researchers said the biological explanation remains unclear.
For the study published in PLOS ONE, researchers analyzed data from 2,622 adults who participated in the 2017–2018 cycle of the CDC’s National Health and Nutrition Examination Survey. Participants were grouped as never users, past users, or current users; current use meant marijuana or hashish had been used on at least one day during the previous 30 days.
The investigators used vibration-controlled transient elastography, a noninvasive test that estimates liver fat through the controlled attenuation parameter and liver stiffness through liver stiffness measurement. After adjusting for factors including age, sex, body mass index, smoking, alcohol intake, diabetes, hypertension, and other health conditions, current marijuana use was associated with lower odds of steatosis compared with never use. Past use was not significantly associated with lower steatosis after adjustment. The association was also observed among participants who did not report heavy alcohol consumption.
The study did not find a significant relationship between marijuana use and liver fibrosis, the buildup of scar tissue that can lead to cirrhosis. That distinction is important: less measured liver fat is not the same as protection from progressive liver disease. The researchers also did not establish that marijuana caused the difference. Because the analysis examined data collected at one point in time, it cannot determine whether marijuana use changed liver health or whether other differences between users and nonusers accounted for the result.
The findings have several additional limitations. Marijuana use was self-reported, and the analysis did not fully account for diet or physical activity. The researchers could not assess the type, potency, or dose of marijuana, establish a dose-response relationship, or exclude every possible liver condition and medication that can promote steatosis. The authors therefore called for longitudinal and mechanistic studies before cannabis or its compounds could be considered as a treatment strategy.
For people with fatty liver disease, established care still centers on identifying and managing contributing conditions, improving diet, increasing physical activity, and achieving gradual weight loss when appropriate. The National Institute of Diabetes and Digestive and Kidney Diseases says that losing at least 3% to 5% of body weight can reduce liver fat, while greater weight loss may improve inflammation and fibrosis. Treatment options have also evolved since this study: the FDA has approved resmetirom and semaglutide for certain adults with noncirrhotic metabolic dysfunction-associated steatohepatitis—formerly called NASH—with moderate-to-advanced fibrosis. Those approvals do not make marijuana an established treatment for fatty liver disease.
