Q: I just found out that I have hepatitis C. I feel fine. I heard that milk thistle is good for the liver. Does it help people with hepatitis C?

A: More than 3 million Americans are infected with the virus that causes hepatitis C. About three-quarters of them are baby boomers -- anyone born between 1945 and 1965. Many of them got it through a blood transfusion.

Like you, most people are not aware they've been infected with the virus unless they get tested. Even without symptoms, chronic hepatitis C can cause the liver to become inflamed as the body fights the infection. Inflamed liver tissue can become scarred. Scar tissue replaces healthy tissue.

The liver is a resilient organ. It can heal if the illness is caught and treated successfully. But when scarring continues and becomes serious, it leads to cirrhosis and a poorly functioning liver.

More than half of Americans seek alternative treatments for medical ailments. There is the perception that milk thistle helps heal a damaged liver, so it's not surprising that many people with hepatitis C use it, alone or combined with doctor-prescribed drugs.

According to the results of a study just published in the Journal of the American Medical Association, silymarin was no more effective than a placebo. Silymarin is the active ingredient in milk thistle extract.

Two different doses of silymarin were tested. One of the doses was much higher than what most people take. But even that dose did not appear to dampen liver inflammation. Although the study didn't specifically address side effects, milk thistle extract did not appear to cause harm.

It's great that you got tested for the virus. The U.S. Centers for Disease Control and Prevention recommends that anyone born between 1945 and 1965 should have a one-time blood test for hepatitis C. Younger people at increased risk should also get tested.

Treatments can slow the infection and limit the damage hepatitis C causes. The first treatment used is pegylated interferon plus ribavirin. It's the most effective. But response rates are only 50 percent to 60 percent.

The U.S. Food and Drug Administration has approved two new antiviral drugs to treat hepatitis C. They are boceprevir (Victrelis) and telaprevir (Incivek). Either one can be combined with interferon and ribavirin. This triple therapy is 30 percent more effective than the standard double therapy.

(Howard LeWine, M.D., is a practicing internist at Brigham and Women's Hospital, Boston, MA, and Chief Medical Editor of Internet Publishing at Harvard Health Publications, Harvard Medical School.)

(For additional consumer health information, please visit http://www.health.harvard.edu.)