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  • Black cohosh (Cimicifuga racemosa)
    • Date: March 25, 1998HC# 012781-131

    Re:Prof. Tyler writes about Black Cohosh

    Tyler, Varro. The bright side of black cohosh Prevention. :.

    Black cohosh (Cimicifuga racemosa) is a woodland plant native to North America. It was used by the Native Americans primarily in the treatment of women's diseases. The roots and racemes (underground stems) are the medicinal parts of the plant. This short article discusses the therapeutic benefits of black cohosh, along with a little history of its use. The article also contains Dr. Tyler's answers to questions about wild yam and Siberian ginseng.

    Black cohosh was introduced to the white settlers and later became the active ingredient in a popular turn-of-the-century remedy known as 'Lydia Pinkham's Vegetable Compound.' It was sold as a cure-all for women's complaints such as premenstrual syndrome (PMS) and symptoms of menopause. While critics had attributed the effect of the remedy to the 18 percent alcohol content, a daily dose of Vegetable Compound actually contained a therapeutic dose of black cohosh.

    The therapeutic activity of black cohosh is due to some of its constituents, primarily triterpenes and flavonoids. Some of these compounds act on the pituitary to suppress the secretion of luteinizing hormone (LH). LH is associated with many of the uncomfortable symptoms of menopause, such as hot flashes, night sweats, headaches, heart palpitations, and the drying and thinning of the vaginal walls. Unlike hormone replacement therapy (a combination of estrogen and progestin), black cohosh is selective in its effect and does not alter the production of the other pituitary hormones, follicle stimulating hormone (FSH) and prolactin. The result is fewer side effects than standard hormone replacement therapy.

    Black cohosh also contains compounds that bind to estrogen receptors, mimicking estriol. Estriol is not associated with increased risk of breast, ovarian, or endometrial cancers, like a related compound, estradiol. Other constituents of black cohosh produce a mild sense of relaxation.

    In an uncontrolled study of 812 women, black cohosh had a positive effect on the psychological symptoms of menopause. Over a 12 week period, the plant extract improved conditions such as irritability, anxiety, difficulties in concentration, depression, hot flashes, and sleeplessness. Forty-one percent of the women reported 'very good' results, and another 41 percent reported 'good' results with the use of the proprietary extract, made in Germany.

    A double-blind study compared black cohosh extract with conjugated estrogens and a placebo in 80 participants over a 12 week period. The effectiveness of the herb was superior for both psychological and physiological symptoms of menopause. Another trial found black cohosh better than a placebo at relieving hot flashes and vaginal dryness in 110 women.

    Black cohosh has been approved by the German equivalent of the FDA (Commission E) for the treatment of PMS, painful menstruation, and menopausal symptoms. A therapeutic daily dose is 40 milligrams. The only reported side effect is occasional stomach upset. No other contraindications or drug interactions are known. Long-term safety has not been evaluated, and experts recommend limiting treatment to three to six months.

    Black cohosh should not be mistaken for blue cohosh (Caulophyllum thalictroides), as safety and efficacy has not been established for the latter. Dr. Varro also recommends consulting with a physician before self-medicating with black cohosh.

    In answer to a question about the therapeutic effects of wild yam (Dioscorea species), Prof. Tyler says that the steroidal precursors found in the plant may be converted to various androgens in the laboratory, but there is no evidence that they change into useful hormones in the human body. The perceived hormonal activity of wild yam products may be due to 'spiking' of the remedy with a chemical that produces hormonal effects. Thus the claims of ads for these products should be viewed with some skepticism.

    - Leela Devi, MSN, RN

    Enclosure Bin #131Referenced article reprinted by permission of PREVENTION Magazine. Copyright 1997 Rodale Press, Inc. All rights reserved. For subscription information, call 1-800-666-2503.