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Int J Mol Epidemiol Genet 2012;3(1):18-29

Original Article
Correlations of urinary phytoestrogen excretion with lifestyle factors and
dietary intakes among middle-aged and elderly Chinese women

Xiaoyan Wu, Hui Cai, Yu-Tang Gao, Qi Dai, Honglan Li, Qiuyin Cai, Gong Yang, Adrian A Franke, Wei Zheng, Xiao Ou Shu

Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center and Vanderbilt-Ingram Cancer Center,
Nashville, TN, USA; Visiting from Department of Biostatistics, Public Health College, Harbin Medical University, Harbin, P. R.
China; Department of Epidemiology, Shanghai Cancer Institute, Shanghai, P. R. China; Cancer Research Center of Hawaii,
Honolulu, HI, USA

Received November 25, 2011; accepted December 16, 2011; Epub February 5, 2012; Published February 28, 2012

Abstract: Isoflavones and lignans, two major groups of phytoestrogens, have been postulated to have multiple health benefits,
including anti-estrogenic, anti-cancer, pro-cardiovascular health, and ameliorating menopausal symptoms. Urinary excretion of
isoflavonoids, including daidzein, genistein, glycitein, O-desmethylangolensin (O-DMA), dihydrodaidzein, dihydrogenistein, and
equol, and lignans, including enterodiol and enterolactone, have been used as biomarkers of phytoestrogen exposure in
epidemiologic studies. We evaluated the urinary excretion of phytoestrogens and their correlations with lifestyle and dietary
factors among 2,165 women who participated in the Shanghai Women’s Health Study (SWHS), a population-based
prospective cohort study of 74,942 urban Chinese women aged 40-70 years at study enrollment (1996-2000). The medians (in
nmol/mg creatinine) were: isoflavonoids, 17.13; daidzein, 5.57; genistein, 2.41; glycitein, 0.94; O-DMA, 1.52; dihydrodaidzein,
0.81; dihydrogenistein, 0.19; equol, 0.11; enterodiol, 0.30; and enterolactone, 1.18. These levels are 2- (enterodiol) to 126- (O-
DMA) fold higher than levels among US women similar in age range with the exception of enterolactone, for which a similar
level was observed for both populations. Urinary isoflavonoid excretion was higher among older women and women who
engaged in regular exercise and significantly associated with soy food intake, but was inversely related to fruit intake. Urinary
excretions of dihydrodaidzein, dihydrogenistein, equol, enterodiol, and enterolactone were inversely associated with body mass
index (BMI). Urinary excretion of isoflavones correlated with soy food intake and healthy lifestyle but was inversely associated
with fruit intake among middle-aged and elderly Chinese women. Our study adds important information to the rapidly growing
body of research on the potential health benefits of phytoestrogens. (IJMEG1111007).

Keywords: Isoflavonoids, lignans, phytoestrogens, dietary intakes, lifestyle factors

Address all correspondence to:
Dr. Xiao-Ou Shu
Division of Epidemiology
2525 West End Avenue, Suite 600
IMPH, Nashville, USA.
Tel: 37203-1738
E-mail: xiao-ou.shu@vanderbilt.edu