Cigarette smoking combined with the hepatitis C virus is known to be a heavy
risk factor in developing primary hepatocellular carcinoma. (Int J Cancer
While many people are aware of smoking's negative effect on the lungs, less consideration is usually given to its effects on the liver. Tobacco and marijuana smoke are rich airborne stews of toxic benzpyrene, polycyclic aromatic hydrocarbons, cyanide, acetaldehyde, tars, acrolein, etc. Since these get into the bloodstream through the lungs, the liver must detoxify them. And virtually all the constituents of smoke are known to be at least mildly liver-damaging (The Liver: Master Organ for Optimal Nutrition).
A recent study biopsied 310 Hep C patients. 176 were current smokers (who were more often males, younger, alcohol consumers, and more often had a history of IVDU than those who had never smoked.) The results were adjusted to consider these factors. The authors concluded that “Smoking increases the severity of hepatic lesions in patients with chronic hepatitis C.” Source: Hepatology 2001;34:121-125, “Cigarette smoking and hepatic lesions in patients with chronic hepatitis C.