Use of Plant-Based Therapies and Menopausal Symptoms: A Systematic Review and Meta-analysis.

IMPORTANCE: Between 40% and 50% of women in Western countries use complementary therapies to manage menopausal symptoms.

OBJECTIVE: To determine the association of plant-based therapies with menopausal symptoms, including hot flashes, night sweats, and vaginal dryness.

DATA SOURCES: The electronic databases Ovid MEDLINE, EMBASE, and Cochrane Central were systematically searched to identify eligible studies published before March 27, 2016. Reference lists of the included studies were searched for further identification of relevant studies.

STUDY SELECTION: Randomized clinical trials that assessed plant-based therapies and the presence of hot flashes, night sweats, and vaginal dryness.

DATA EXTRACTION: Data were extracted by 2 independent reviewers using a predesigned data collection form.

MAIN OUTCOMES AND MEASURES: Hot flashes, night sweats, and vaginal dryness.

RESULTS: In total, 62 studies were identified, including 6653 individual women. Use of phytoestrogens was associated with a decrease in the number of daily hot flashes (pooled mean difference of changes, -1.31 [95% CI, -2.02 to -0.61]) and vaginal dryness score (pooled mean difference of changes, -0.31 [95% CI, -0.52 to -0.10]) between the treatment groups but not in the number of night sweats (pooled mean difference of changes, -2.14 [95% CI, -5.57 to 1.29]). Individual phytoestrogen interventions such as dietary and supplemental soy isoflavones were associated with improvement in daily hot flashes (pooled mean difference of changes, -0.79 [-1.35 to -0.23]) and vaginal dryness score (pooled mean difference of changes, -0.26 [-0.48 to -0.04]). Several herbal remedies, but not Chinese medicinal herbs, were associated with an overall decrease in the frequency of vasomotor symptoms. There was substantial heterogeneity in quality across the available studies, and 46 (74%) of the included randomized clinical trials demonstrated a high risk of bias within 3 or more areas of study quality.

CONCLUSIONS AND RELEVANCE: This meta-analysis of clinical trials suggests that composite and specific phytoestrogen supplementations were associated with modest reductions in the frequency of hot flashes and vaginal dryness but no significant reduction in night sweats. However, because of general suboptimal quality and the heterogeneous nature of the current evidence, further rigorous studies are needed to determine the association of plant-based and natural therapies with menopausal health.