Milk thistle is a Mediterranean herb used to treat conditions of the liver and gallbladder. The primary active component of milk thistle, silymarin, acts in your body as an antioxidant, anti-inflammatory and bioflavonoid. In addition, the herbal supplement may be used to treat symptoms of menopause. Medline Plus explains that the effect in these cases may be due to milk thistle's ability to increase the effectiveness of estrogen. The herb may provide relief for some women, but its use may also adversely affect hormonally driven conditions.
Check with your doctor before using any herbal supplement.
Milk Thistle's Effect on Estrogen
Milk thistle's active component, silymarin, appears to attach to estrogen receptors in the body. This can prevent estrogen from attaching, leaving additional estrogen in the bloodstream. A 2003 article published in the "Journal of Biochemistry and Molecular Biology" found that administration of milk thistle appeared to have selective estrogenic effects. In this study, milk thistle increased the activity of bone-building osteoclasts but had no effect or an inverse effect on the cells of the uterus. Despite this supposed selectivity, Medline Plus explains that milk thistle may help to break down estrogen pills, causing the estrogen to be less effective.
Milk Thistle and Fertility
The estrogenic effects of milk thistle may cause hormonal changes that can impair fertility. A 2002 study published in the "Egyptian Journal of Hospital Medicine" found that milk thistle prevented fertile female rats from becoming pregnant. The study also found alterations in FSH, a hormone that facilitates pregnancy. Research regarding the effects of milk thistle on pregnant or breast-feeding women is limited. However, because of the potential for infertility as a result of hormonal changes, the University of Maryland Medical Center explains that milk thistle should be avoided by women who are pregnant or plan to become pregnant.
Milk Thistle and Menopause
Women who are in the midst of menopause, defined as the cessation of menstrual cycles, may experience uncomfortable symptoms caused by rapidly fluctuating hormone levels. For this reason, milk thistle may be suggested to relieve symptoms such as hot flashes and night sweats. However, research has not supported this use of the herb. In addition, Medline Plus cautions women who have a risk or history of hormonally driven cancer to avoid using milk thistle. These cancers, including breast and ovarian forms, may develop or worsen with the administration of an estrogenic herb.
Considerations
If you have an allergy to the aster, or daisy, family of flowers, avoid milk thistle, as it is a member of this family. The most commonly experienced side effects when taking milk thistle are gastrointestinal upset and itching, according to MayoClinic.com. In rare cases, milk thistle may lead to a hypoglycemic reaction, characterized by shakiness, sweating and nausea. Milk thistle seeds may have less estrogenic effects than other plant parts. Consult your doctor before using this herb.
References
- MayoClinic.com; Milk Thistle (Silybum Marianum); Safety
- JHB Inc.; Milk Thistle Extract Preparation; December 14, 2001
- Medline Plus: Milk Thistle
- National Cancer Institute: Milk Thistle
- National Center for Complimentary and Alternative Medicine: Milk Thistle
- "Egyptian Journal of Hospital Medicine"; Hormonal Profile and Histopathological Study on the Influence of Silymarin on Both Female and Male Albino Rats; Enas A.M.Khalil; 2002
- "Journal of Steroid Biochemistry and Molecular Biology"; Silymarin is a Selective Estrogen Receptor Beta...; D. Wuttke-Seidlova, et al.; 2003
Member Comments