Effect of isoflavone supplementation on menopausal symptoms:
a systematic review and meta-analysis of randomized controlled trials
- Affiliations
-
- 1Department of Food Science and Nutrition, Jeju National University, Jeju 63243, Korea
- 2Interdisciplinary Graduate Program in Advanced Convergence Technology and Science, Jeju National University, Jeju 63243, Korea
- 3Department of Radiation Oncology, Korea University Ansan Hospital, Ansan 15355, Korea
- 4Korea University Medical College, Seoul 02841, Korea
- 5Division of Functional Food & Nutrition, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Korea
- 6Department of Food Science and Technology, Seoul National University of Science and Technology, Seoul 01811, Korea
- 7Department of Food and Nutrition, School of Bio-Health Convergence, Sungshin Women’s University, Seoul 01133, Korea
Abstract
- BACKGROUND/OBJECTIVES
Complementary and alternative medicines can be used to alleviate climacteric symptoms that significantly affect the quality of life of postmenopausal women. Isoflavones are the most common plant-based therapies for postmenopausal changes, but the results of previous studies have been controversial.
MATERIALS/METHODS
To investigate whether isoflavones would affect menopausal symptoms as well as ovarian hormones, we performed a systematic review and metaanalysis. The PubMed and EMBASE databases were used to perform the systematic search.
Included studies were limited to randomized controlled trials (RCTs) assessing the impact of isoflavone supplementation on menopausal symptoms.
RESULTS
Eleven studies were included for the final quantitative assessment. Isoflavone intervention was varied between 49.3 and 135 mg of isoflavones per day for 12 wk–2 yrs.
The meta-analysis showed that supplementation of isoflavones significantly increased the estradiol levels (standardized mean difference [SMD] = 0.615, P = 0.035) and Kupperman index (SMD = 3.121, P = 0.003) but had no significant effect on hot flashes, folliclestimulating hormone, and luteinizing hormone. However, both estradiol and the Kupperman index showed significant heterogeneity among studies (I2 = 94.7%, P < 0.001 and I2 = 98.1%, P < 0.001, respectively).
CONCLUSIONS
Although the results showed a significant SMD in estradiol and the Kupperman index, the results should be interpreted with caution due to the high heterogeneity. Further validation with a larger RCT will be necessary. Overall, isoflavone supplementation has distinct effects on the climacteric symptoms and hormonal changes in postmenopausal women.