Vaginal, Endometrial, and Reproductive Hormone Effects of Herbal Remedies and Soy
By Dónal P. O'Mathúna, PhD. Dr. O'Mathúna is Senior Lecturer in Ethics, Decision-Making & Evidence, School of Nursing, Dublin City University, Ireland; he reports no financial relationships to this field of study.
Source: Reed SD, et al. Vaginal, endometrial, and reproductive hormone findings: Randomized, placebo-controlled trial of black cohosh, multibotanical herbs, and dietary soy for vasomotor symptoms: The Herbal Alternatives for Menopause (HALT) Study. Menopause 2008;15:51-58.
The aim of this study was to evaluate vaginal, endometrial, and reproductive hormone effects of three herbal regimens compared with placebo and hormone therapy (HT).
Design: This was a one-year, randomized, double-blind, placebo-controlled trial of 351 women, ages 45-55, with two or more vasomotor symptoms per day. Women were randomly assigned to: 1) black cohosh; 2) a multibotanical containing black cohosh; 3) the same multibotanical plus dietary soy counseling; 4) HT; or 5) placebo. Women were ineligible if they had used HT in the previous three months or menopausal herbal therapies in the previous month. Data on vaginal cytology and dryness were collected at baseline and three and 12 months. Daily menstrual diaries were maintained by 313 women with a uterus, and abnormal bleeding was evaluated. Serum estradiol, follicle-stimulating hormone, luteinizing hormone, and steroid hormone-binding globulin were assessed at baseline and 12 months among 133 postmenopausal women. Gynecologic outcomes of the five groups were compared.
Results: The five groups did not vary in baseline vaginal cytology profiles, vaginal dryness, menstrual cyclicity, or hormone profiles. The HT group had a lower percentage of parabasal cells and vaginal dryness than the placebo group at three and 12 months (P < 0.05). Abnormal bleeding occurred in 53 of 313 (16.9%) women. There were no differences in frequency of abnormal bleeding between any of the herbal and placebo groups, whereas women in the HT group had a greater risk than those in the placebo group (P < 0.001). Among postmenopausal women, HT significantly decreased follicle-stimulating hormone and increased estradiol; none of the herbal interventions showed significant effects on any outcomes at any time point.
Conclusion: Black cohosh, used alone or as part of a multibotanical product with or without soy dietary changes, had no effects on vaginal epithelium, endometrium, or reproductive hormones.
Commentary
Menopausal symptoms are one of the most common indications for which herbal remedies are used by women, especially following the reports in 2002 of higher incidences of certain adverse events after long-term use of hormone replacement therapy. Black cohosh is one of the most commonly used herbal remedies for treating menopausal symptoms. In 2006, its sales were eighth among all herbal remedy sales in the United States at almost $10 million.1 However, the findings from clinical trials of black cohosh's effectiveness have not been consistent. Earlier trials were mostly favorable, but limited in their quality, numbers of subjects, and duration. More recent trials have found black cohosh to be as effective in relieving menopausal symptoms as some synthetic steroids used in hormone replacement therapy.2 Black cohosh has fewer adverse effects than hormone replacement therapy.3
The Herbal Alternatives for Menopause (HALT) Study is the largest and longest randomized, double-blind trial of black cohosh for menopausal symptoms published to date. The primary outcomes of the HALT Study were published in 2006.4 These found no significant differences between the herbal remedies and placebo for any of the measures of vasomotor symptom frequency or intensity. No differences were found at three, six, or 12 months or for the overall average values. During the course of the study, lasting one year, the menopausal symptoms for those in the placebo group decreased by almost one-third in both frequency and severity.
The article reviewed here reported further outcomes concerning vaginal cytology, vaginal dryness, menstrual cyclicity, and several hormone profiles. As with the primary outcomes, the herbal interventions did not show significant improvements over placebo on any of the outcomes reported here. The vaginal cytology allowed calculation of the maturation index (MI), which reflects the response of vaginal tissues to the presence of estrogen or estrogen-like substances. The lack of significant differences between the herbal interventions and placebo in MI and vaginal dryness would go against claims that black cohosh has estrogen-like activity.
Concerns have been expressed that black cohosh might increase the risk of endometrial hyperplasia. The HALT Study did not find evidence to support this concern. In contrast, no women in the study were diagnosed with endometrial hyperplasia over the 12 months of the trial. The lack of change in other hormone levels supports this finding. These results are in agreement with another study directly examining the effect of black cohosh on endometrial tissues.5
The multiherb remedy used in this study, ProGyne, was labeled as containing several herbs commonly recommended to relieve menstrual symptoms. The daily dose would deliver black cohosh 200 mg, alfalfa 400 mg (Medicago sativa), boron 4 mg, chaste tree 200 mg (Vitex agnus-castus), dong quai 400 mg (Angelica sinensis), false unicorn 200 mg (Chamaelirium luteum), licorice 200 mg (Glycyrrhiza glabra), oats 400 mg (Avena sativa), pomegranate 400 mg (Punica granatum), and Siberian ginseng 400 mg (Eleutherococcus senticosus, standardized constituents eleutherosides E 0.8% and B 0.5%). Independent assessment of the herbal product failed to detect the presence of dong quai, false unicorn, and pomegranate. Such results raise concerns about the quality of the product, but also point to the importance of evaluating the quality of herbal remedies tested in clinical trials.
It should also be noted that this study did not use the proprietary black cohosh preparation (Remifemin®), which has been the subject of much the previous clinical research. Differences between the products and how they are prepared could account for some of the conflicting results in clinical trials.
References
1. Blumenthal M, et al. Total sales of herbal supplements in United States show steady growth. HerbalGram 2006;71:64-66.
2. Bai W, et al. Efficacy and tolerability of a medicinal product containing an isopropanolic black cohosh extract in Chinese women with menopausal symptoms: A randomized, double blind, parallel-controlled study versus tibolone. Maturitas 2007; 58:31-41.
3. Huntley A, Ernst E. A systematic review of the safety of black cohosh. Menopause 2003;10:58-64.
4. Newton KM, et al. Treatment of vasomotor symptoms of menopause with black cohosh, multibotanicals, soy, hormonal therapy or placebo: A randomized trial. Ann Intern Med 2006;145:869-879.
5. Raus K, et al. First-time proof of endometrial safety of the special black cohosh extract (Actaea or Cimicifuga racemosa extract) CR BNO 1055. Menopause 2006;13: 678-691.
O’Mathuna D. Vaginal, Endometrial, and Reproductive Hormone Effects of Herbal Remedies and Soy. 2008;10:78-79.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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