Short-term phytoestrogen supplementation alters insulin-like growth factor profile but not lipid or antioxidant status.
Phytoestrogens are plant compounds that have been proposed to have a variety of health benefits. The aim of this study was to assess the effects of these compounds on a number of physiological endpoints. Subjects were given a single intake of a phytoestrogen-rich (80 mg total phytoestrogens) supplement containing soy, rye and linseed (Phase 1), followed by a week-long intervention using the same supplement (Phase 2) (80 mg total phytoestrogens daily). A number of biochemical endpoints were assessed including urinary phytoestrogen metabolites, lipids, antioxidant status, DNA damage and insulin-like growth factor-1 (IGF-1) and IGF binding protein-1 (IGFBP-1) and -3 (IGFBP-3). Ten healthy female subjects took part in the study. Excretion of the isoflavones genistein, daidzein and equol in urine increased in both phases of the study. No other endpoint was altered in Phase 1. However, in Phase 2, concentrations of IGF-1 and IGFBP-3 were increased by phytoestrogen supplementation [IGF-1, median (IQ range), baseline 155 (123, 258), postweek 265 (228, 360) ng/ml, P<.05; IGFBP-3, baseline 3725 (3631, 4196), postweek 4420 (4192, 4935) ng/ml, P<.05]. There was no effect of supplementation on lipids or markers of antioxidant status. Short-term phytoestrogen supplementation increases urinary phytoestrogen excretion and increases IGF-1 and IGFBP-3. These results require elucidation in further controlled studies.
Woodside
Jayne V
JV
Department of Medicine, Centre for Cardiovascular and Genetics Research, The Queen's University of Belfast, Belfast BT12 6BJ, UK. j.woodside@qub.ac.uk
Campbell
Maeli J
MJ
Denholm
Erica E
EE
Newton
Lynne
L
Honour
John W
JW
Morton
Michael S
MS
Young
Ian S
IS
Leathem
Anthony J C
AJ
D000328:Adult; D000975:Antioxidants / Q000032:analysis*; D004249:DNA Damage; D004032:Diet; D060754:Equol; D005260:Female; D019597:Flax; D019833:Genistein / Q000652:urine; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D007529:Isoflavones / Q000652:urine; D007700:Kinetics; D017705:Lignans / Q000652:urine; D008055:Lipids / Q000097:blood*; D008875:Middle Aged; D048789:Phytoestrogens / Q000008:administration & dosage* / Q000652:urine; D013025:Glycine max
C007610:4',7-dihydroxy-3,4-dihydroisoflavone; D000975:Antioxidants; D018972:Insulin-Like Growth Factor Binding Protein 3; D007529:Isoflavones; D017705:Lignans; D008055:Lipids; D048789:Phytoestrogens; D060754:Equol; C004742:daidzein; D007334:Insulin-Like Growth Factor I; C029498:2,3-bis(3'-hydroxybenzyl)butane-1,4-diol; D019833:Genistein