Actaea racemosa or Cimicifuga racemosa is commonly called black cohosh. This botanical is used primarily for managing menopausal symptoms. An increasing number of dietary supplements specifically targeting women in menopause have appeared on the market. This popularity highlights the need for a critical evaluation of the effectiveness and safety of these products, because there are several concerns regarding their toxicity. Consult a health care professional before using botanicals to treat any disease.
Toxic Substances in Black Cohosh
Although most herbal dietary supplements are considered safe, a few contain constituents that can be converted to reactive biological metabolites, causing toxicity. In the October 2010 issue of Chemical and Biological Interactions, a review of medical literature identified compounds found in botanicals, which are increasingly popular due to their natural origin and the assumption that they're safe alternatives to prescription drugs. The authors said that compounds called quinones are found in sassafras, kava and black cohosh. These represent toxins of an intermediate reactivity that can generate damage to DNA and interfere with pharmaceuticals in a dose- and time-dependent manner.
Treatment of Menopause
The November 2008 issue of the American Journal of Obstetrics and Gynecology included a review of adverse effects of black cohosh used to treat symptoms that can occur during menopause. The aim of the article was to evaluate the clinical evidence for or against the safety of black cohosh. The authors conducted systematic literature searches in computerized databases and included case reports and observational studies. Most of the article reported that black cohosh is safe but cautioned that it has been associated with serious safety concerns that urgently require further investigation.
Literature Search
An article in the December 2005 American Journal of Medicine assessed the evidence for safety and therapeutic benefits of botanical preparations used to relieve menopausal symptoms. The author searched medical databases and considered only studies if they were controlled trials of a single botanical administered orally to perimenopausal or postmenopausal women, and if they included a placebo for comparison. Topical preparations, botanical combinations and dietary supplements with soy or protein were excluded. The article said most studies indicate that extract of black cohosh improves menopause-related symptoms; however, it identified shortcomings in the trials. This author found case reports of possible hepatotoxicity that have been published, even though many previous safety reviews suggest that black cohosh is well tolerated and that adverse events are rare when it's used properly.
Labeling of Black Cohosh
The July 2008 edition of Menopause included another review of the safety and efficacy of black cohosh. The author noted that regulatory agencies in Australia, Canada and the European Union have released statements questioning the "potential association" between black cohosh and toxicity of the liver. In response to this query, the Dietary Supplement Information Expert Committee of the U.S. Pharmacopeia's Council of Experts evaluated current safety information for black cohosh products. It found 30 reports of liver damage with possible links to black cohosh, but none were certain. In short, the pharmacological and toxicological information did not reveal adverse information. Based on this review, it determined that black cohosh products should be labeled to include a cautionary statement.
References
- "Chemical and Biological Interactions"; Biological reactive intermediates (BRIs) formed from botanical dietary supplements; B. Dietz et al; October 2010
- American Journal of Obstetrics and Gynecology: Black cohosh (Cimicifuga racemosa): a systematic review of adverse events; F. Borrelli et al; November 2008
- American Journal of Medicine: Menopause: a review of botanical dietary supplements; T. Low-Dog; December 2005
- Menopause: United States Pharmacopeia review of the black cohosh case reports of hepatotoxicity; G. Mahady et al; July 2008
Member Comments