Three Reasons to Be Wary of Recently Publicized Milk Thistle Doubt
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The extract of milk thistle is widely accepted as the most effective herbal remedy for liver ailments, including chronic Hepatitis C. This popular herb is taken by those who don’t want or are ineligible for Hepatitis C treatment, have previously failed treatment or who want to increase their chances of a successful treatment. Based on a long history of being liver-specific, a potent antioxidant, an anti-inflammatory and an immune modulator, it’s no surprise that people with chronic Hepatitis C often supplement with milk thistle extract. However, a recent presentation at the 2011 American Association for the Study of Liver Diseases Annual Meeting cast doubt on this popular liver wellness practice.
The basis of hundreds of medical studies, milk thistle extract has demonstrated a beneficial liver effect in the lab, in animal studies and human trials more often than it has shown no benefit:
- As published in the March 2011 edition of the Journal of Research in Medical Sciences, researchers found that patients with chronic Hepatitis C taking milk thistle (650 mg of silymarin a day) for six months had improved levels of Hepatitis C RNA, improved liver enzyme levels (ALT and AST), reduced hepatic fibrosis and improved quality of life.
- As published in the February 2008 edition of Hepatology, a large trial of over 1,000 previous non-responders with advanced chronic Hepatitis C found that supplementing with milk thistle resulted in significant improvements in fatigue, nausea, liver pain, anorexia, muscle and joint pain and general health.
Read the article “Milk Thistle Bolsters HCV Treatment” to learn of five more studies of milk thistle and Hepatitis C.
Although there are many documented reasons for people with chronic Hepatitis C to take a milk thistle supplement, there are several institutions that work diligently to discredit milk thistle’s impact on liver health.
According to a recent study under the direction of Michael W. Fried, M.D., professor of medicine and director of hepatology at the University of North Carolina at Chapel Hill, milk thistle was found to do little more than placebo for fighting the Hepatitis C virus. Based on his study evaluating 154 participants, patients with Hepatitis C who failed interferon treatment showed no symptoms of improvement or slowing of disease progression with milk thistle extract.
After 24 weeks, Fried’s study’s primary endpoint was a normal alanine transaminase (ALT) level or a 50 percent reduction of ALT. The secondary endpoints included any significant difference in ALT, Hepatitis C RNA levels or participants’ quality of life. Using oral dosing of a milk thistle extract, Fried’s study found that both primary and secondary endpoints did not differ between those on milk thistle and those on placebo. While this conclusion may appear to be discouraging, there are three reasons to be cautious of Fried’s assumption that milk thistle is ineffectual on the liver – absorption, damage control and associations:
1. Absorbability– Although a standard formulation of milk thistle’s most clinically effectual constituent was used in Fried’s study, absorbability was not addressed. Clinicians familiar with the pharmacodynamics of milk thistle know that it is a notoriously difficult substance to be absorbed. As described by an independent research company, the bioavailability of milk thistle extract is low due to only 20 to 50 percent absorption in the gastrointestinal tract. In acknowledgment of this characteristic, Fried admitted that intravenous administration of milk thistle appeared to be superior.
Researchers in a previous study used an intravenous (IV) formulation of milk thistle in Hepatitis C infected previous non-responders. In just two weeks, a significant reduction of Hepatitis C RNA was seen in nearly half of the study’s participants. Fried recognized this study and discussed the need for a more potent oral formulation; however, innovation on enhancing milk thistle’s absorbability was notably absent from his presentation. Improving bioavailability by up to ten times, an Italian nutraceutical company has already devised a solution for milk thistle’s poor absorption via phytosome technology. Known as silybin phytosome, a more potent oral milk thistle formulation already exists in the marketplace.
2. Damage Control – Extraneous damaging factors must be controlled when testing any substance’s ability to influence liver health while infected with the Hepatitis C virus. This is particularly important when it comes to alcohol consumption, which could easily negate any potential benefits of the tested substance. Unfortunately, the Fried study made no mention of alcohol restriction (or banning other potentially harmful items) for its participants during the study period.
3. Associations- Regarded as coming from a potentially biased source, research conducted by persons affiliated with or rewarded by a particular cause may be suspect in their conclusions. In medical or pharmaceutical research, reporting of associations is mandatory. Affecting how much credibility we may give to this particular study, Dr. Fried falls under this category, as his best interests are served by supporting the pharmaceutical industry. As stated in the press release, Dr. Fried reports serving as a consultant for Genentech, Tibotec, Vertex, Merck, Abbott, and Pharmasset; receiving grants and other research support from Genentech, Tibotec, Vertex, Merck, Anadys, BMS, and Abbott; serving as an advisor for GlaxoSmithKline – and being a shareholder in Pharmasset.
For certain individuals, there is a possibility that Fried’s conclusion about milk thistle being ineffectual on liver enzymes and Hepatitis C RNA is true. However, this one study defies many more that have found the opposite to be true – and it contains a few reasons to doubt its credibility. Milk thistle may not be a cure for Hepatitis C, but there is an abundance of evidence that intravenous milk thistle extract or the highly absorbable and bioavailable supplement dramatically increase the likelihood of improving liver health.
References:
http://www.medscape.com/viewarticle/753370?src=mp&spon=20, Milk Thistle Proven Ineffective for Treating Liver Disease, Neil Canavan, Retrieved November 26, 2011, Medscape Medical News, 2011.
http://www.ncbi.nlm.nih.gov/pubmed/22091246, Effects of silybum marianum on patients with chronic hepatitis C, Kalantari H., et al, Retrieved November 26, 2011, Journal of Research in Medical Sciences, March 2011.
http://www.ncbi.nlm.nih.gov/pubmed?term=Milk%20Thistle%20Research%20-%20Herbal%20product%20use%20by%20persons%20enrolled%20in%20the%20HALT-C%20Trial, Herbal product use by persons enrolled in the hepatitis C Antiviral Long-Term Treatment Against Cirrhosis (HALT-C) Trial, Seeff, LB, et al, Retrieved November 26, 2011, Hepatology, February 2008.
http://www.salamresearch.com/html/milk_thistle_product.html, Report: Milk Thistle Product, Retrieved November 26, 2011, Salam Research, 2011.
