PI Perspective #46

September 2008     View PDF     En español

Milk thistle may help improve liver health
in people with HIV and hepatitis C

by Alan McCord

Those co-infected with HIV and hepatitis C (HCV) can face significant challenges with sustaining their liver health. This is due to how the two viruses affect the liver over time as well as the ongoing side effects from taking drugs that treat the two diseases. For these and other reasons, there’s an urgent need to find methods of improving liver function for people co-infected with HIV/HCV.

A report from a small study of the popular herbal supplement, milk thistle, was presented at the 2008 International AIDS Conference. The study looked at its ability to improve liver function in co-infected people. Milk thistle, or silybum marianum, has been shown in other studies to benefit liver function in various situations, though many of those studies were not well designed or came to inconsistent conclusions. This study used an extract from the milk thistle seed called silymarin.

This 52-week study of 21 co-infected volunteers examined how safely milk thistle performed. They were randomly assigned to take either a placebo or 180mg of 80% standardized silymarin extract 3 times a day. Out of the 21 who started, 15 finished the study with 7 who were on silymarin and 8 who took placebo. In both groups, volunteers were about equally men and women and were mainly African American and Latino.

The results showed no impact on CD4 counts or HIV or HCV viral loads. There were no serious adverse effects, although the abstract for this study lacked details on what adverse effects were seen. Since HIV viral load was not affected, this suggests that milk thistle may not interact with HIV or HCV drugs, although there was no information on HIV regimens used by study participants.

The most notable result was a trend in lowering the aspartate aminotransferase (AST) levels in those who took milk thistle. (AST is a blood marker that indicates tissue damage in the liver.) There was a decline in AST of 8.4 for those on milk thistle, while the placebo group showed an increase of 27.9 in their ASTs.

Although this looks like good news, people should be careful not to run out and pick up over-the-counter milk thistle products for this use. The study used an extract of milk thistle, which may or may not be found in retail products. These products also often contain other ingredients that can alter their effectiveness. Additionally, since this was a small safety study, not enough data is known about how milk thistle interacts with the various HIV and HCV regimens available today. The degree of improved liver function and how long it may last also need to be furthered studied.