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Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Mar 15, 2015; 6(2): 271-283
Published online Mar 15, 2015. doi: 10.4239/wjd.v6.i2.271
Role of phytoestrogens in prevention and management of type 2 diabetes
Mohammad Talaei, An Pan
Mohammad Talaei, An Pan, Saw Swee Hock School of Public Health, National University of Singapore, Singapore 117549, Singapore
An Pan, Department of Epidemiology and Biostatistics, MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
Author contributions: Talaei M and Pan A contributed to this paper.
Conflict-of-interest: The authors declare no conflicts of interest regarding this manuscript.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: An Pan, PhD, Department of Epidemiology and Biostatistics, MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Rd, Wuhan 430030, Hubei Province, China. panan@hust.edu.cn
Fax: +86-27-83692560
Received: September 21, 2014
Peer-review started: September 22, 2014
First decision: October 16, 2014
Revised: November 4, 2014
Accepted: December 16, 2014
Article in press: December 17, 2014
Published online: March 15, 2015
Abstract

Type 2 diabetes (T2D) has become a major public health threat across the globe. It has been widely acknowledged that diet plays an important role in the development and management of T2D. Phytoestrogens are polyphenols that are structurally similar to endogenous estrogen and have weak estrogenic properties. Emerging evidence from pre-clinical models has suggested that phytoestrogens may have anti-diabetic function via both estrogen-dependent and estrogen-independent pathways. In the current review, we have summarized the evidence linking two major types of phytoestrogens, isoflavones and lignans, and T2D from epidemiological studies and clinical trials. The cross-sectional and prospective cohort studies have reported inconsistent results, which may due to the large variations in different populations and measurement errors in dietary intakes. Long-term intervention studies

using isoflavone supplements have reported potential beneficial effects on glycemic parameters in postmenopausal women, while results from short-term small-size clinical trials are conflicting. Taken together, the current evidence from different study designs is complex and inconsistent. Although the widespread use of phytoestrogens could not be recommended yet, habitual consumption of phytoestrogens, particularly their intact food sources like soy and whole flaxseed, could be considered as a component of overall healthy dietary pattern for prevention and management of T2D.

Keywords: Type 2 diabetes, Phytoestrogen, Isoflavone, Lignan, Epidemiological study, Clinical trial

Core tip: Phytoestrogens are a group of polyphenols that are structurally similar to endogenous estrogen. Animal experiments and pre-clinical models have provided strong evidence that phytoestrogens may have anti-diabetic function via both estrogen-dependent and estrogen-independent pathways. A number of epidemiological studies and clinical trials have thus been conducted in different populations linking two major types of phytoestrogens, isoflavones and lignans, to the prevention and management of diabetes. Although the current evidence is complex and inconsistent, habitual consumption of phytoestrogens, particularly their intact food sources, could be considered as a component of overall healthy dietary pattern for prevention and management of diabetes.