Hepatitis C

PrintHepatitis C is a viral disease of the liver that afflicts an estimated four million Americans. Chronic hepatitis C is typically associated with fatigue, depression, joint pain and liver impairment, including cirrhosis and liver cancer.

Scientists suggest that the endocannabinoid system may moderate aspects of chronic liver disease.[1-2] Population data shows that adults with a history of cannabis use are less likely to suffer from specific liver problems, such as non-alcoholic fatty liver disease (NAFLD), than non-users. Specifically, a 2017 University of Massachusetts study reported that frequent consumers of cannabis were 52 percent less likely to be diagnosed with NAFLD as compared to non-users, while occasional consumers were 15 percent less likely to suffer from the disease.[3] A Stanford University study similarly reported that cannabis use independently predicted a lower risk of suspected NAFLD in a dose-dependent manner. “Active marijuana use provided a protective effect against NAFLD independent of known metabolic risk factors,” authors concluded.[4]

Patients diagnosed with hepatitis C frequently report using cannabis to treat both symptoms of the disease as well as the nausea associated with antiviral therapy.[5-6] An observational study by investigators at the University of California at San Francisco (UCSF) reports that hepatitis C patients who used cannabis were significantly more likely to adhere to their treatment regimen than patients who didn’t use it.[7]

While some early observational studies initially cautioned that heavy cannabis use among hepatitis C patients may adversely impact the liver,[8-10] more recent studies report that cannabis inhalation is not associated with the promotion of liver disease in hepatitis C subjects,[11] and, in some cases, may even act as a protective agent against it.[12-14] Specifically, a 2019 review of nine studies involving nearly six million subjects concluded, “Marijuana use [does] not increase the prevalence or progression of hepatic fibrosis in HCV and HCV-HIV-coinfected patients. On the contrary, we noted a reduction in the prevalence of NAFLD in marijuana users.”[15]

Separate longitudinal data documents that patients co-infected with hepatitis C and HIV who consume cannabis are also less likely to suffer from insulin resistance as compared to non-users.[16] More notably, co-infected HIV/hepatitis C patients with a history of cannabis use possess a reduced mortality risk compared to non-users, according to the results of a five-year longitudinal study published in 2019 in the journal AIDS and Behavior. Authors of the study reported: “Regular/daily cannabis use, elevated coffee intake, and not currently smoking [tobacco] were independently associated with reduced HCV-mortality. … [P]otential benefits of cannabis-based therapies [should be further] investigated.”[17]

REFERENCES

[1] Zamora-Valdes et al. 2005. The endocannabinoid system in chronic liver disease (PDF). Annals of Hepatology 4: 248-254.

[2] Gabbey et al. 2005. Endocannabinoids and liver disease – review. Liver International 25: 921-926.

[3] Adejumo et al. 2017. Cannabis use is associated with reduced prevalence of non-alcoholic fatty liver disease: A cross-sectional study. PLoS One [open access journal].

[4] Kim et al. 2017. Inverse association of marijuana use with nonalcoholic fatty liver disease among adults in the United States. PLoS One [open access journal].

[5] Schnelle et al. 1999. Results of a standardized survey on the medical use of cannabis products in the German-speaking area. Forschende Komplementarmedizin (Germany) 3: 28-36.

[6] MedScape Today. 2004. “Hepatitis C – Current state of the art and future directions.” MedScape Today.

[7] Sylvestre et al. 2006. Cannabis use improves retention and virological outcomes in patients treated for hepatitis C. European Journal of Gastroenterology & Hepatology. 18: 1057-1063.

[8] Hezode et al. 2005. Daily cannabis smoking as a risk factor for progression of fibrosis in chronic hepatitis C. Hepatology 42: 63-71.

[9] Ishida et al. 2008. Influence of cannabis use on severity of hepatitis C disease. Clinical Gastroenterology and Hepatology 6: 69-75.

[10] Parfieniuk and Flisiak. 2008. Role of cannabinoids in liver disease. World Journal of Gastroenterology 14: 6109-6114.

[11] Brunet et al. 2013. Marijuana smoking does not accelerate progression of liver disease in HIV-hepatitis C coinfection: a longitudinal cohort analysis. Clinical Infectious Diseases 57: 663-670.

[12] Nordmann et al. 2017. Daily cannabis and reduced risk of steatosis in human immunodeficiency virus and hepatitis C virus co-infected patients. Journal of Viral Hepatitis [online ahead of print].

[13] Adejumo et al. 2018. Reduced incidence and better liver disease outcomes among chronic HCV infected patients who consume cannabis. Canadian Journal of Gastroenterology & Hepatology.[open access journal].

[14] Barre et al. 2021. Cannabis use and reduced risk of elevated fatty liver index in HIV-HCV co-infected patients: A longitudinal analysis. Expert Review of Anti-Infective Therapy [online ahead of print]. 

[15] Farooqui et al. 2019. Marijuana is not associated with progression of hepatic fibrosis in liver disease: A systemic review and meta-analysisEuropean Journal of Gastroenterology & Hepatology 31: 149-156. 

[16] Patrizia-Carrie et al 2015. Cannabis use and reduced risk of insulin resistance in HIV-HCV infected patients: A longitudinal analysis. Clinical Infectious Diseases 61: 40-48.

[17] Santos et al. 2020. HCV-related mortality among HIV/HCV co-infected patients: The importance of behaviors in the HCV cure eraAIDS and Behavior 24: 1069-1084.