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Meta-Analysis
. 2015 Apr;18(2):260-9.
doi: 10.3109/13697137.2014.966241. Epub 2014 Dec 1.

Efficacy of phytoestrogens for menopausal symptoms: a meta-analysis and systematic review

M-N Chen  1 , C-C Lin, C-F Liu
Affiliations
Meta-Analysis

Efficacy of phytoestrogens for menopausal symptoms: a meta-analysis and systematic review

M-N Chen et al. Climacteric. 2015 Apr.

Abstract

Objective: To perform a meta-analysis examining the efficacy of phytoestrogens for the relief of menopausal symptoms.

Methods: Medline, Cochrane, EMBASE, and Google Scholar databases were searched until September 30, 2013 using the following key words: vasomotor symptoms, menopausal symptoms, phytoestrogens, isoflavones, coumestrol, soy, red clover. Inclusion criteria were (1) randomized controlled trial (RCT), (2) perimenopausal or postmenopausal women experiencing menopausal symptoms, (3) intervention with an oral phytoestrogen. Outcome measures included Kupperman index (KI) changes, daily hot flush frequency, and the likelihood of side-effects.

Results: Of 543 potentially relevant studies identified, 15 RCTs meeting the inclusion criteria were included. The mean age of the subjects ranged from 49 to 58.3 and 48 to 60.1 years, respectively, in the placebo and phytoestrogen groups. The number of participants ranged from 30 to 252, and the intervention periods ranged from 3 to 12 months. Meta-analysis of the seven studies that reported KI data indicated no significant treatment effect of phytoestrogen as compared to placebo (pooled mean difference = 6.44, p = 0.110). Meta-analysis of the ten studies that reported hot flush data indicated that phytoestrogens result in a significantly greater reduction in hot flush frequency compared to placebo (pooled mean difference = 0.89, p < 0.005). Meta-analysis of the five studies that reported side-effect data showed no significant difference between the two groups (p = 0.175).

Conclusion: Phytoestrogens appear to reduce the frequency of hot flushes in menopausal women, without serious side-effects.

Keywords: CLIMACTERIC; ESTROGEN; HOT FLUSH; ISOFLAVONE; LIGNAN; MENOPAUSE; META-ANALYSIS.

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Figures

Figure 1
Figure 1
Flow diagram of study selection
Figure 2
Figure 2
Meta-analysis (a) with sensitivity evaluation (b) for change in Kupperman index between placebo and phytoestrogen groups (seven studies included). The random-effects approach was used due to significant heterogeneity (Q = 370.03, I2 = 98.38, p < 0.001). CI, confidence interval
Figure 3
Figure 3
Meta-analysis (a) with sensitivity evaluation (b) for change of hot flush frequency between placebo and phytoestrogen groups (10 studies included). The random-effects approach was used due to significant heterogeneity (Q = 22.75, I2 = 60.43, p = 0.007). CI, confidence interval
Figure 4
Figure 4
Meta-analysis (a) with sensitivity evaluation (b) for the likelihood of side-effects between the placebo and phytoestrogen groups (five studies included). The random-effects approach was used due to significant heterogeneity (Q = 10.15, I2 = 60.60, p = 0.038). OR, odds ratio; CI, confidence interval
Figure 5
Figure 5
Evaluation of publication bias for (a) Kupperman index, (b) hot flush frequency, and (c) side-effects
Figure 6
Figure 6
Quality assessment
See this image and copyright information in PMC

Comment in

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