December 26, 2005

Milk thistle ineffective for liver disease

By Anne Harding

NEW YORK (Reuters Health) - Milk thistle, an herbal remedy
used worldwide for liver disease, does not appear to be
effective, and there is not enough evidence to conclude that it
is safe, an international team of researchers has concluded.

"We can't see beneficial effects, we can't exclude harmful
effects, and in order to know more we need to do more
randomized trials to find out do they actually help," Dr.
Christian Gluud of Copenhagen University Hospital in Denmark,
the study's lead author, told Reuters Health.

The market for milk thistle is enormous, Gluud noted, given
that as many as 1 billion people around the world have liver
disease due to alcoholism or hepatitis B or C. It could even be
larger, he added, because some people may decide to take milk
thistle for prevention.

Gluud and his colleagues reviewed 13 clinical trials of
milk thistle for liver disease due to alcoholism or hepatitis B
or C. The gold standard for clinical trials is for them to be
placebo-controlled and double-blind, meaning neither patients
nor the study administrators know whether a patient is taking
the real drug or placebo. Just six of the trials analyzed met
this standard.

As they report in the American Journal of Gastroenterology,
the researchers found no effect of milk thistle versus placebo
on mortality rates or liver disease complications. While the
remedy appeared to reduce death from liver-related causes when
all data was included, an analysis limited to the best-quality
studies found no effect.

No increased risk of adverse events was seen with milk
thistle, but this does not necessarily mean the remedy is
harmless, Gluud said. Even the highest-quality clinical trials,
he noted, can miss catching potential harm from drugs.

According to Gluud, herbal remedies should be held to the
same standards as conventional medicine. Sellers of such
remedies must be required, he said, to have good evidence for
any claims they make.

"My advice to people is don't use them before you have seen
valid, trustworthy, low bias clinical trials that these drugs
may actually benefit you more than they may harm you," he

SOURCE: The American Journal of Gastroenterology, November