Smoking Marijuana Worsens Liver Damage of Individuals Infected with Hepatitis C

24 Mar 2013

Hepatitis C (HCV) virus is the most common liver infection in America affecting nearly 4 million people. Many of these individuals have been treated for their infection but many more have progressive liver disease for a number of reasons. Some people do not respond to the known treatments, others do not know they have the infection and still others participate in a life style that continues to damage their liver. The most common scenario is continued exposure to the virus from intravenous drug use, regular tobacco smoking or from daily consumption of alcohol.

Recently, it has been discovered that another risk factor that causes the acceleration of liver disease in those infected with HCV is the regular use of marijuana. There are now three independent studies published that all reveal this same finding (see references).

This new revelation is disconcerting in light of the fact that the most common recreational drug used in the United States is marijuana and it use is rising because it is becoming legalized both for medical and recreational use in many parts of the country.

The vast majority of my patients with HCV infection also smoke marijuana on a regular basis for various reasons. Some claim it helps with fatigue from liver disease, some feel it helps their appetite, others just use it recreationally and some feel it helps with their aches and pains.

When I inform these individuals about the risk they are posing to their liver, they certainly are free to continue using or change their lifestyle. But, unfortunately many individuals are unaware of their HCV infection and are also using marijuana because of the relaxed attitude about its use in America.

When the question to legalize marijuana in the state of Washington (my residence) was being debated last year the questions about its safety were never brought to the attention of the voters. Now that it is legal to openly smoke marijuana in the state, I wonder how many individuals are damaging their liver.

This is a public health issue as the fastest rising cancer incidence in America is now liver cancer that results from HCV-induced liver disease and other forms of liver disease. If people with HCV infection are not educated about this added risk of smoking marijuana many may eventually die from liver cancer.

Hepatology 2005;42:63-71.
Clinical Gastroenterology and Hepatology 2008;6:69-75.
Gastroenterology 2008;134:432-439.