In about 10% of cases, non-alcoholic fatty liver disease progresses to non-alcoholic steatohepatitis (NASH), a dangerous condition that ultimately produces liver fibrosis, cirrhosis, and even cancer.33,34 Milk thistle shows promise for this extremely serious form of liver disease as well.
In experimental non-alcoholic steatohepatitis, even a crude milk thistle extract reduced severity, lowered blood levels of liver enzymes, and dramatically reduced liver cytokine levels, while increasing liver glutathione (the liver’s protective natural antioxidant).36 Silybin has been shown to completely restore vital liver functions in animals with non-alcoholic steatohepatitis, improving insulin sensitivity and markers of oxidative and inflammatory damage.26,37
It also suppressed the transformation of normal liver structural cells into the tough, inelastic tissue characteristic of liver fibrosis and cirrhosis, the end-stage phases of liver disease that follows non-alcoholic steatohepatitis.28
Viral hepatitis is a catch-all phrase for infections by several very different viruses that affect the liver, causing liver damage and raising the risk for liver cancer—especially in the case of hepatitis B and C. Both hepatitis B and C can set up chronic, long-lived infection (chronic active hepatitis) that can progress to fibrosis and cirrhosis.38
Silymarin treatment in acute viral hepatitis can speed the normalization of liver enzymes in the blood, indicating a regression of active liver damage.39
A group of patients with chronic active hepatitis took 240 mg of silybin combined with phosphatidylcholine, or placebo, twice daily for 7 days.40 Supplemented patients had significant drops in all markers of liver damage, while control patients experienced no changes.
While effective against hepatitis-induced liver damage, oral silymarin produces no reduction in the number of virus particles infecting the body, but studies of silymarin given intravenously reveal a substantial antiviral effect in hepatitis C patients who have not responded to standard antiviral treatment.41
The characteristic yellowish skin of hepatitis victims is the result of high levels of bilirubin, a liver-produced substance normally excreted in stool. But patients receiving oral silymarin for hepatitis (regardless of which virus type) had earlier improvement in both skin coloration and clinical markers of liver damage compared to control patients.42
Milk thistle extracts have been shown to benefit cirrhosis, the end-stage result of liver damage. Cirrhosis can result from multiple causes, including alcoholic and non-alcoholic fatty liver disease, viral hepatitis, and many toxins.43 In other words, cirrhosis doesn’t represent a single diagnosis, but a largely preventable progression of the oxidation and inflammation produced by all those other causes.
Unfortunately, prevention has so far eluded most medical interventions. As a result, those with cirrhosis are faced with either a slow and uncomfortable death, or a liver transplant, which is costly, dangerous, and not available to everyone.
Fortunately, milk thistle extracts are showing considerable promise in this desperate situation. One early study found that in people with alcohol-induced cirrhosis, those taking silymarin survived longer than control subjects.44 A later study confirmed that finding, with 58% of silymarin-treated patients surviving longer than 4 years, compared with just 39% of the placebo group.45
Even when liver disease has reached the stage of cirrhosis, silymarin treatment can normalize elevated liver enzymes in the blood, indicating that it has slowed the progression of liver damage.46 Proof of this comes from a study in an extremely challenging population: alcoholic diabetics with cirrhosis. In that group, silymarin treatment, 600 mg/day, reduced markers of cell membrane oxidation and improved insulin resistance.3 In fact, silymarin recipients had less overproduction of their own insulin, and required less insulin by injection, compared with control patients.3 The early stages of type II diabetes are characterized by excess pancreatic secretion of insulin to suppress elevated glucose. As type II diabetes progresses, the pancreas loses its ability to produce enough insulin and some patients require insulin injections. A therapy that reduces the amount of insulin needed by injection, or its excess production in the pancreas is considered beneficial.