May 24, 2005 – Two new studies on the effectiveness of black cohosh in relieving symptoms of menopause have just been published. One concludes that it is effective, the other does not.
The results of the first study, a 12-week, double-blind, placebo-controlled clinical trial in Germany with 304 postmenopausal women1, indicate that the end-use product Remifemin, a standardized extract of black cohosh, is more effective than a placebo in relieving symptoms of menopause. According to the researchers, it would be particularly effective against hot flashes. The results obtained in this regard were comparable to those of synthetic hormones commonly used for this purpose in conventional medicine.
According to gynecologist Henneicke-von Zepelin, who was part of the team that conducted this trial, the mode of action of black cohosh is different from that of replacement hormones. The plant would act in particular by modulating the production of the hypothalamic hormone, also called “trigger factor”. Note that Ms. Henneicke-von Zepelin is employed by the manufacturer of Remifemin.
The second study consisted of a crossover trial, conducted over eight weeks in the United States with 132 women. According to the results obtained, Remifemin would not have been shown to be more effective than placebo in relieving hot flashes.2, although a pilot test carried out last year by the same researchers had produced similar results to those of the German researchers3. Note, this time, that the study was published by researchers from the North Central Cancer Treatment Group, an organization active in research into hormonal treatments to relieve symptoms of menopause.
Very popular in Europe for relieving symptoms of menopause, especially since doubts have been expressed about the risks associated with the use of replacement hormones, black cohosh is still very little recommended by North American doctors.
It therefore seems that it is still too early to say definitively on the effectiveness of black cohosh.
Pierre Lefrançois – PasseportSanté.net
According to Reuters Health and The Globe and Mail
1. Osmers R, Friede M, et al. Efficacy and safety of isopropanolic black cohosh extract for climacteric symptoms.Obstet Gynecol. 2005 May; 105 (5): 1074-83.
2. Mayo Clinic. Study Finds Black Cohosh No Better Than Placebo in Treating Hot Flashes. Presentation at a conference of the American Society of Clinical Oncology (ASCO), United States, May 2005. [Consulté le 20 mai 2005]. www.mayoclinic.org
3. Pockaj BA, Loprinzi CL, et al. Pilot evaluation of black cohosh for the treatment of hot flashes in women.Cancer Invest. 2004; 22 (4): 515-21.