Evidence of a lack of effect of a phytoestrogen regimen on the levels of C-reactive protein, E-selectin, and nitrate in postmenopausal women.
Phytoestrogens are thought to be beneficial to vascular health. Possible mechanisms of action could involve C-reactive protein (CRP), endothelial E-selectin, and nitric oxide. We therefore designed a randomized, placebo-controlled, double-blind trial in which we studied the effects of isoflavonoids on CRP, E-selectin, and nitrate-nitrite (NO(x); reflecting the release of nitric oxide) in postmenopausal women. Fifty-six postmenopausal women (FSH > 30 U/liter) with a history of breast cancer used (in a randomized order) phytoestrogen (114 mg isoflavonoids) or placebo tablets daily for 3 months; the treatment regimens were crossed over after a 2-month washout period. The serum levels of CRP and E-selectin, and plasma levels of NO(x) were measured before and on the last day of each treatment. The phytoestrogen regimen did not affect the levels of either CRP (P = 0.584) or NO(x) (P = 0.270), but the levels of E-selectin were reduced by 4.0% (2.9 ng/ml; P = 0.031) during phytoestrogen use and by 2.2% (1.3 ng/ml; P = 0.023) during placebo use. No difference was found at any marker at 3 months between the groups. In conclusion, our data, suggesting neutral effects of phytoestrogens on CRP, E-selectin, and nitric oxide, fail to support a vasoprotective role of phytoestrogens.
Nikander
E
E
Department of Obstetrics and Gynecology, Helsinki University Central Hospital, FIN-00029 Helsinki, Finland. eini.nikander@pp.fimnet.fi
Metsä-Heikkilä
M
M
Tiitinen
A
A
Ylikorkala
O
O
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms; D002097:C-Reactive Protein / Q000378:metabolism*; D018592:Cross-Over Studies; D019040:E-Selectin / Q000097:blood*; D004968:Estrogens, Non-Steroidal / Q000008:administration & dosage / Q000097:blood; D005260:Female; D006801:Humans; D007529:Isoflavones / Q000008:administration & dosage* / Q000097:blood; D008875:Middle Aged; D009566:Nitrates / Q000097:blood*; D048789:Phytoestrogens; D008517:Phytotherapy; D028321:Plant Preparations / Q000008:administration & dosage* / Q000097:blood
D019040:E-Selectin; D004968:Estrogens, Non-Steroidal; D007529:Isoflavones; D009566:Nitrates; D048789:Phytoestrogens; D028321:Plant Preparations; C004742:daidzein; D002097:C-Reactive Protein