Rotterdam, The Netherlands—Supplements available on drugstore shelves could be helpful in reducing some of the symptoms associated with menopause, according to a new study.
An analysis of more than 60 studies, published in the Journal of the American Medical Association, found that some plant-based therapies could modestly reduce the frequency of hot flashes and vaginal dryness but had no effect on night sweats.

Background information in the articles notes that, because of potentially negative health effects of hormone replacement therapy on cardiovascular health and breast cancer, as many as half of women in Western countries opt to use complementary therapies, including plant-based therapies, to treat menopause symptoms. Those include oral use of phytoestrogens such as dietary soy isoflavones and soy extracts; herbal remedies such as red clover and black cohosh; and Chinese and other medicinal herbs.

Study authors led by researchers from Erasmus University Medical Center in Rotterdam note that, while randomized trials have been used to evaluate the therapies, most of the studies were small, had short follow-up periods, inconsistent findings, or other issues.

To remedy that, the study team reviewed and analyzed 62 randomized clinical trials involving 5,553 women that assessed plant-based therapies and the presence of hot flashes, night sweats, and vaginal dryness. 

Results indicate that use of phytoestrogens was generally associated with a decrease in the number of daily hot flashes, pooled mean difference of changes, –1.31, and vaginal dryness score, pooled mean difference of changes, –0.31, between the treatment groups but not in the number of night sweats, pooled mean difference of changes, –2.14.

Individual phytoestrogen interventions such as dietary and supplemental soy isoflavones, meanwhile, were associated with improvement in daily hot flashes and vaginal dryness score. On the other hand, supplementing with red clover, a rich source of phytoestrogens formononetin, biochanin A, daidzein, and genistein, was identified as improving night sweats but not reducing the frequency of hot flashes, according to the report.

In addition, several herbal remedies, although not Chinese medicinal herbs such as dong quai, were associated with an overall decrease in the frequency of vasomotor symptoms. No benefit was found for use of black cohosh, a commonly used agent, to improve menopause symptoms, study authors point out.

The study posits a “plausible biological argument for these associations of phytoestrogens with improved symptoms. The two major subtypes of phytoestrogen, isoflavones and lignans have a chemical structure similar to that of estradiol (i.e., a form of estrogen) and therefore also appear to have estrogen-like properties. However this mechanism of action also could be associated with adverse effects such as endometrial hyperplasia.”

Researchers caution, however, that the past research varied significantly in terms of scientific rigor and quality. 

“Because of general suboptimal quality and the heterogeneous nature of the current evidence,” the study authors conclude, “further rigorous studies are needed to determine the association of plant-based and natural therapies with menopausal health.”

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