TY - JOUR
T1 - Effect of a soymilk supplement containing isoflavones on urinary F2 isoprostane levels in premenopausal women
AU - Nhan, Sukwan
AU - Anderson, Karl E.
AU - Nagamani, Manubai
AU - Grady, James J.
AU - Lu, Lee Jane W.
N1 - Funding Information:
Research supported by NIH CA65628, NIH CA95545, AICR grant 01B110, U.S. Army MRMC under DADM17-01–1-0417, NCRR GCRC MO1 RR00073, and NIH NIEHS ES06676. Address correspondence to Lee-Jane W. Lu, PhD, at Department of Preventive Medicine and Community Health, The University of Texas Medical Branch, 700 Harborside Drive, Galveston, TX 77555–1109. Phone: (409) 772–1730. E-mail [email protected].
PY - 2005
Y1 - 2005
N2 - Epidemiological studies have associated soy diets with reduced risk of breast and some other cancers, and oxidative cellular damage may contribute to the development of these and other diseases. We tested the effect of a soy milk supplement rich in isoflavones on a measure of cellular lipid peroxidation in a controlled feeding study. Eight premenopausal women consumed a constant diet that included soy-milk containing 113-207 mg/day total isoflavones and 4 mo later a constant soy diet low (<5 mg/day) in isoflavones, both for a complete menstrual cycle. The average daily urinary excretions of daidzein and genistein were 24.6 ± 10.1 and 9.2 ± 6.1 mg/day, respectively, during the high-isoflavone soy diet and were below the detection limit during the low-isoflavone diet. F2 isoprostane 8-iso-PGF-2α excretion varied widely within and between subjects, and the group mean was not significantly different during the high- and low-isoflavone soy diet (7.67 ± 1.13 and 8.65 ± 1.18 nmol/12 h, mean ± SD, respectively). However, individual changes in 8-iso-PGF-2α between the two soymilk drinks were significantly associated with age (r = -0.87; P = 0.006) and several measures of isoflavone exposure, namely, daidzein dose (r = 0.81; P = 0.015), combined daidzein and genistein dose (r = 0.77; P = 0.03), and total urinary excretion of isoflavones (daidzein, genistein, and equol) (r = 0.71; P = 0.05). The findings suggest that soy isoflavones may reduce lipid peroxidation in an age-dependent manner, with greater effects in older women, and with lower doses of isoflavones.
AB - Epidemiological studies have associated soy diets with reduced risk of breast and some other cancers, and oxidative cellular damage may contribute to the development of these and other diseases. We tested the effect of a soy milk supplement rich in isoflavones on a measure of cellular lipid peroxidation in a controlled feeding study. Eight premenopausal women consumed a constant diet that included soy-milk containing 113-207 mg/day total isoflavones and 4 mo later a constant soy diet low (<5 mg/day) in isoflavones, both for a complete menstrual cycle. The average daily urinary excretions of daidzein and genistein were 24.6 ± 10.1 and 9.2 ± 6.1 mg/day, respectively, during the high-isoflavone soy diet and were below the detection limit during the low-isoflavone diet. F2 isoprostane 8-iso-PGF-2α excretion varied widely within and between subjects, and the group mean was not significantly different during the high- and low-isoflavone soy diet (7.67 ± 1.13 and 8.65 ± 1.18 nmol/12 h, mean ± SD, respectively). However, individual changes in 8-iso-PGF-2α between the two soymilk drinks were significantly associated with age (r = -0.87; P = 0.006) and several measures of isoflavone exposure, namely, daidzein dose (r = 0.81; P = 0.015), combined daidzein and genistein dose (r = 0.77; P = 0.03), and total urinary excretion of isoflavones (daidzein, genistein, and equol) (r = 0.71; P = 0.05). The findings suggest that soy isoflavones may reduce lipid peroxidation in an age-dependent manner, with greater effects in older women, and with lower doses of isoflavones.
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U2 - 10.1207/s15327914nc5301_9
DO - 10.1207/s15327914nc5301_9
M3 - Article
C2 - 16351509
AN - SCOPUS:30444437174
SN - 0163-5581
VL - 53
SP - 73
EP - 81
JO - Nutrition and Cancer
JF - Nutrition and Cancer
IS - 1
ER -